--- - chapter_identifier: alaska confidence: "Given the evidence base and remaining uncertainties:\r\nVery high confidence for summer sea ice decline. High confidence for summer sea ice disappearing by mid-century.\r\nVery high confidence for altered marine ecosystems, greater ship access, and increased vulnerability of communities to coastal erosion.\r\nHigh confidence regarding offshore development opportunity.\r\n" evidence: "The key message and supporting chapter text summarize extensive evidence documented in the Alaska TIR.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Technical input reports (85) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input. \r\nAlthough various models differ in the projected rate of sea ice loss, more recent CMIP5 models6e730a84-66a2-4e74-96cb-c9e6824cf185 that most accurately reconstruct historical sea ice loss project that late-summer sea ice will virtually disappear by the 2030s, leaving only remnant sea ice. \r\nEvidence is strong about the impacts of sea ice loss.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Because the sea ice cover plays such a strong role in human activities and Arctic ecosystems, loss of the ice cover is nearly certain to have substantial impacts.9d6e6cea-7b84-4ab3-8b27-b245b3800e4d \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/alaska/finding/summer-sea-ice-reduction-effects.yaml identifier: summer-sea-ice-reduction-effects ordinal: 1 process: "A central component of the assessment process was the Alaska Regional Climate assessment workshop that was held September 12-15, 2012, in Anchorage with approximately 20 attendees; it began the process leading to a foundational Technical Input Report (TIR).6e174e7d-28f7-4ce4-9141-c378d82b4f53 The report consists of 148 pages of text, 45 figures, 8 tables, and 27 pages of references. Public and private citizens or institutions were consulted and engaged in its preparation and expert review by the various agencies and non-governmental organizations (NGOs) represented by the 11-member TIR writing team. The key findings of the report were presented at the Alaska Forum on the Environment and in a regularly scheduled, monthly webinar by the Alaska Center for Climate Assessment and Policy, with feedback then incorporated into the report.\r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences. These included careful expert review of the foundational TIR6e174e7d-28f7-4ce4-9141-c378d82b4f53 and of approximately 85 additional technical inputs provided by the public, as well as the other published literature and professional judgment. These discussions were followed by expert deliberation of draft key messages by the writing team in a face-to-face meeting before each key message was selected for inclusion in the Report. These discussions were supported by targeted consultation with additional experts by the lead author of each message, and they were based on criteria that help define “key vulnerabilities” (Ch. 26: Decision Support)." report_identifier: nca3 statement: 'Arctic summer sea ice is receding faster than previously projected and is expected to virtually disappear before mid-century. This is altering marine ecosystems and leading to greater ship access, offshore development opportunity, and increased community vulnerability to coastal erosion.' uncertainties: "Important new evidence confirmed many of the findings from a prior Alaska assessment (http://nca2009.globalchange.gov/alaska), which informed the 2009 NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a \r\nEvidence from improved models (for example,6e730a84-66a2-4e74-96cb-c9e6824cf185) and updated observational data from satellite, especially new results, clearly show rapid decline in not only extent but also mass and thickness of multi-year ice,f1a5ebbc-6aba-405c-861f-62d88bae060e information that was not available in prior assessments. \r\nNearly all studies to date published in the peer-reviewed literature agree that summer Arctic sea ice extent is rapidly declining and that, if heat-trapping gas concentrations continue to rise, an essentially ice-free summer Arctic ocean will be realized before mid-century. However, there remains uncertainty in the rate of sea ice loss, with the models that most accurately project historical sea ice trends currently suggesting nearly ice-free conditions sometime between 2021 and 2043 (median 2035).6e730a84-66a2-4e74-96cb-c9e6824cf185 Uncertainty across all models stems from a combination of large differences in projections among different climate models, natural climate variability, and uncertainty about future rates of fossil fuel emissions. \r\nEcosystems: \r\nThere is substantial new information that ocean acidification, rising ocean temperatures, declining sea ice, and other environmental changes are affecting the location and abundance of marine fish, including those that are commercially important, those used as food by other species, and those used for subsistence.34d601bb-7781-4785-bde8-3b10be88994c,b33c6aba-d652-4f20-9809-e0948a06bcfd,7ab1d9e1-75a1-48c5-8d85-02258496f919,d8db2d8d-d1d1-4d24-b662-67b26b8ac92b,215b842d-1f34-40c2-8e0e-04965ad303d6,8d612e8b-b96e-48db-a8b4-17bcc3550f7d However, the relative importance of these potential causes of change is highly uncertain.\r\nRegarding offshore oil and gas development, a key uncertainty is the price of fossil fuels. Viable avenues to improving the information base are determining the primary causes of variation among different climate models and determining which climate models exhibit the best ability to reproduce the observed rate of sea ice loss.\r\nCoastal erosion:\r\nThere is new information that lack of sea ice causes storms to produce larger waves and more coastal erosion.6e174e7d-28f7-4ce4-9141-c378d82b4f53 An additional contributing factor is that coastal bluffs that were “cemented” by permafrost are beginning to thaw in response to warmer air and ocean waters, and are therefore more vulnerable to erosion.1fb3ac6c-0180-4195-ae1d-5d28ef1ade64 Standard defensive adaptation strategies to protect coastal communities from erosion such as use of rock walls, sandbags, and riprap have been largely unsuccessful.550d81ed-d1b4-4b46-bf5e-ea47ab3e5dea There remains considerable uncertainty, however, about the spatial patterns of future coastal erosion.\r\n" uri: /report/nca3/chapter/alaska/finding/summer-sea-ice-reduction-effects url: ~ - chapter_identifier: alaska confidence: "High confidence that glacier mass loss in Alaska and British Columbia is high, contributing 20% to 30% as much to sea level rise as does shrinkage of the Greenland Ice Sheet.\r\nHigh confidence that due to glacier mass loss there will be related impacts on hydropower production, ocean circulation, fisheries, and global sea level rise. \r\n\r\n" evidence: "The key message and supporting chapter text summarize extensive evidence documented in the Alaska Technical Input Report.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Technical input reports (85) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input. \r\nEvidence that glaciers in Alaska and British Columbia are shrinking is strong and is based on field studies,2c0068c4-bde0-4d10-8d9b-9135868ec825,16e8187e-a734-4d60-ae4c-95021657d756 energy balance models,c426adb7-b055-4726-80f1-82d7846f46c0 LIDAR remote sensing,b6bd09ac-2fd9-4720-b8a3-089a37a42e95,0a0ac996-a92d-4584-9d24-f94dd27844c6 and satellite data, especially new lines of evidence from the Gravity Recovery and Climate Experiment (GRACE) satellite.0c05253e-78bc-4ca2-80a9-468a42bf0060,0a0ac996-a92d-4584-9d24-f94dd27844c6,f755e69d-3511-4ec0-baab-4c1d0663888e,5b564190-3aa3-4704-ac92-a1d439727fea\r\nEvidence is also strong that Alaska ice mass loss contributes to global sea level rise,6e84ea40-9754-4273-9281-f8d6fc563917 with latest results permitting quantitative evaluation of losses globally.7578c40e-dfbf-435c-bb83-36eada4f0095\r\nNumerous peer-reviewed publications describe implications of recent increases, but likely longer-term declines, in water input from glacial rivers to reservoirs and therefore hydropower resources.09961450-e217-4cf4-b11f-fab19c8ea9ed,6e174e7d-28f7-4ce4-9141-c378d82b4f53,3132328b-bb58-47c8-a3b2-53054951f331\r\nGlacial rivers account for 47% of the freshwater input to the Gulf of Alaska3132328b-bb58-47c8-a3b2-53054951f331 and are an important source of organic carbon,dbc23531-4169-4dad-bfbd-fac80c5f40bb,cc023336-fbff-49f7-a87f-d5353f24c903 phosphorus,a955e6c1-f593-435f-aea3-61fc83bfd7b8 and irone27d4082-48ed-4f8b-a477-dfabe8e4b40e that contribute to the high productivity of near-shore fisheries.cc023336-fbff-49f7-a87f-d5353f24c903,7312e00b-5455-4a22-9ad9-dd805a462473,27f2a255-5137-466d-a34d-6899eb4132fa,93088c9e-c280-4065-88cf-934e8de6697f Therefore, it is projected that the changes in discharge of glacial rivers will affect ocean circulation patterns and major U.S. and locally significant fisheries. \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/alaska/finding/glacier-shrinkage-implications.yaml identifier: glacier-shrinkage-implications ordinal: 2 process: "A central component of the assessment process was the Alaska Regional Climate assessment workshop that was held September 12-15, 2012, in Anchorage with approximately 20 attendees; it began the process leading to a foundational Technical Input Report (TIR).6e174e7d-28f7-4ce4-9141-c378d82b4f53 The report consists of 148 pages of text, 45 figures, 8 tables, and 27 pages of references. Public and private citizens or institutions were consulted and engaged in its preparation and expert review by the various agencies and non-governmental organizations (NGOs) represented by the 11-member TIR writing team. The key findings of the report were presented at the Alaska Forum on the Environment and in a regularly scheduled, monthly webinar by the Alaska Center for Climate Assessment and Policy, with feedback then incorporated into the report.\r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences. These included careful expert review of the foundational TIR6e174e7d-28f7-4ce4-9141-c378d82b4f53 and of approximately 85 additional technical inputs provided by the public, as well as the other published literature and professional judgment. These discussions were followed by expert deliberation of draft key messages by the writing team in a face-to-face meeting before each key message was selected for inclusion in the Report. These discussions were supported by targeted consultation with additional experts by the lead author of each message, and they were based on criteria that help define “key vulnerabilities” (Ch. 26: Decision Support)." report_identifier: nca3 statement: 'Most glaciers in Alaska and British Columbia are shrinking substantially. This trend is expected to continue and has implications for hydropower production, ocean circulation patterns, fisheries, and global sea level rise.' uncertainties: "Important new evidence confirmed many of the findings from a prior Alaska assessment (http://nca2009.globalchange.gov/alaska), which informed the 2009 NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a \r\nAs noted above, major advances from GRACE and other datasets now permit analyses of glacier mass loss that were not possible previously. \r\nKey uncertainties remain related to large year-to-year variation, the spatial distribution of snow accumulation and melt, and the quantification of glacier calving into the ocean and lakes. Although most large glaciated areas of the state are regularly measured observationally, extrapolation to unmeasured areas carries uncertainties due to large spatial variability. \r\nAlthough there is broad agreement that near-shore circulation in the Gulf of Alaska is influenced by the magnitude of freshwater inputs, little is known about the mechanisms by which near-term increases and subsequent longer-term decreases in glacier runoff (as the glaciers disappear) will affect the structure of the Alaska Coastal Current and smaller-scale ocean circulation, both of which have feedback on fisheries. \r\nThe magnitude and timing of effects on hydropower production depend on changes in glacial mass, as described above. \r\n" uri: /report/nca3/chapter/alaska/finding/glacier-shrinkage-implications url: ~ - chapter_identifier: alaska confidence: "Very high confidence that permafrost is warming.\r\nHigh confidence that landscapes in interior Alaska are getting drier, although the relative importance of different mechanisms is not completely clear. \r\nMedium confidence that thawing permafrost results in more wildfires. There is high confidence that wildfires have been increasing in recent decades, even if it is not clear whether permafrost thaw or hotter and drier weather is more important. \r\nHigh confidence that climate change will lead to increased maintenance costs in future decades. Low confidence that climate change has led to increased maintenance costs of infrastructure in recent decades.\r\nVery high confidence that ecological changes will cause Alaska to become a source of greenhouse gases to the atmosphere, even though evidence that Alaska is currently a carbon source is only suggestive. \r\n" evidence: "The key message and supporting chapter text summarize extensive evidence documented in the Alaska Technical Input Report.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Technical input reports (85) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input. \r\nPrevious evidence that permafrost is warming9e5e3d14-8ead-4580-90ce-fc5549cc4c47 has been confirmed and enhanced by more recent studies.6a2437ca-35ac-44c4-bd6d-f38b69efdd6a,5a612de8-a07d-48c0-a7ca-c4b705157070 The most recent modeling efforts (for example, Avis et al. 2011; Jafarov et al. 2012622eec71-9cca-4231-949d-a24ac34f45fa,85521935-98c8-4946-a895-6dc3e3dce4d7) extend earlier resultsb5c9b9f8-3f13-4cb6-b4d6-e0b44cfe34c9,4920e8b8-02c6-48d6-9bb7-d466fda80871 and project that permafrost will be lost from the upper few meters from large parts of Alaska by the end of this century. \r\nEvidence that permafrost thaw leads to drier landscapes40707b8e-1def-49f8-bc7c-75355ef5a597,2db000de-866a-4a94-96d9-4a778cc81bad is beginning to accumulate, especially as improved remote sensing tools are applied to assess more remote regions.622eec71-9cca-4231-949d-a24ac34f45fa\r\nSatellite data has expanded the capacity to monitor wildfire across the region, providing additional evidence of wildfire extent.ea92c82d-60a2-47e5-b48e-31b32ae85b6d This new evidence has led to increased study that is beginning to reveal impacts on ecosystems and wildlife habitat, but much more work is needed to understand the extent of natural resilience. \r\nImpacts of permafrost thaw on the maintenance of infrastructureab52be13-af0f-4dad-ba10-db328e20159d,269e8640-18d1-4f61-aa0f-55eb3fbea2d2,3800bb8e-2dea-4285-9aaf-42f7eecc3e0d,41fa8b2f-6581-4633-85d8-f7e3d3ff475a,058cd073-9f08-4809-9522-451f48581dbf is currently moderate but rapidly accumulating. Evidence that permafrost thaw will jeopardize efforts to offset fossil fuel emissions is suggestive (Ch. 2: Our Changing Climate).509ac5ff-2189-49aa-b046-4ab9ea19d6ea,0e2a44dc-cf4a-490b-ab13-8f1b8faa3cb7,fcc250cc-66a0-416f-aa0c-400c9d02e458\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/alaska/finding/rising-permafrost-temperature-effects.yaml identifier: rising-permafrost-temperature-effects ordinal: 3 process: "A central component of the assessment process was the Alaska Regional Climate assessment workshop that was held September 12-15, 2012, in Anchorage with approximately 20 attendees; it began the process leading to a foundational Technical Input Report (TIR).6e174e7d-28f7-4ce4-9141-c378d82b4f53 The report consists of 148 pages of text, 45 figures, 8 tables, and 27 pages of references. Public and private citizens or institutions were consulted and engaged in its preparation and expert review by the various agencies and non-governmental organizations (NGOs) represented by the 11-member TIR writing team. The key findings of the report were presented at the Alaska Forum on the Environment and in a regularly scheduled, monthly webinar by the Alaska Center for Climate Assessment and Policy, with feedback then incorporated into the report.\r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences. These included careful expert review of the foundational TIR6e174e7d-28f7-4ce4-9141-c378d82b4f53 and of approximately 85 additional technical inputs provided by the public, as well as the other published literature and professional judgment. These discussions were followed by expert deliberation of draft key messages by the writing team in a face-to-face meeting before each key message was selected for inclusion in the Report. These discussions were supported by targeted consultation with additional experts by the lead author of each message, and they were based on criteria that help define “key vulnerabilities” (Ch. 26: Decision Support)." report_identifier: nca3 statement: 'Permafrost temperatures in Alaska are rising, a thawing trend that is expected to continue, causing multiple vulnerabilities through drier landscapes, more wildfire, altered wildlife habitat, increased cost of maintaining infrastructure, and the release of heat-trapping gases that increase climate warming.' uncertainties: "Important new evidence confirmed many of the findings from a prior Alaska assessment (http://nca2009.globalchange.gov/alaska), which informed the 2009 NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a \r\nThis evidence included results from improved models and updated observational data. The assessment included insights from stakeholders collected in a series of distributed engagement meetings that confirm the relevance and significance of the key message for local decision-makers. \r\nKey uncertainties involve: 1) the degree to which increases in evapotranspiration versus permafrost thaw are leading to drier landscapes; 2) the degree to which it is these drier landscapes associated with permafrost thaw, versus more severe fire weather associated with climate change, that is leading to more wildfire; 3) the degree to which the costs of the maintenance of infrastructure are associated with permafrost thaw caused by climate change versus disturbance of permafrost due to other human activities; and 4) the degree to which climate change is causing Alaska to be a sink versus a source of greenhouse gases to the atmosphere.\r\n" uri: /report/nca3/chapter/alaska/finding/rising-permafrost-temperature-effects url: ~ - chapter_identifier: alaska confidence: "Given the evidence base and remaining uncertainties:\r\nHigh confidence of increased ocean temperatures and changes in chemistry. \r\nMedium confidence that fisheries will be affected.\r\n" evidence: "The key message and supporting chapter text summarize extensive evidence documented in the Alaska Technical Input Report.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Technical input reports (85) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input. \r\nNumerous peer-reviewed publications describe evidence that ocean temperatures are rising and ocean chemistry, especially pH, is changing.6e174e7d-28f7-4ce4-9141-c378d82b4f53 New observational data from buoys and ships document increasing acidity and aragonite under-saturation (that is, the tendency of calcite and aragonite in shells to dissolve) in Alaskan coastal waters.\r\nAccumulating strong evidence suggests that these changes in ocean temperature and chemistry, including pH, will likely affect major Alaska marine fisheries, although the relative importance of these changes and the exact nature of response of each fishery are uncertain.34d601bb-7781-4785-bde8-3b10be88994c,b33c6aba-d652-4f20-9809-e0948a06bcfd,7ab1d9e1-75a1-48c5-8d85-02258496f919,79042600-c08d-4569-8741-7f00d598cd02,d8db2d8d-d1d1-4d24-b662-67b26b8ac92b,215b842d-1f34-40c2-8e0e-04965ad303d6,8d612e8b-b96e-48db-a8b4-17bcc3550f7d\r\nAlaska’s commercial fisheries account for roughly 50 percent of the United States’ total wild landings. Alaska led all states in both volume and ex-vessel value of commercial fisheries landings in 2009, with a total of 1.84 million metric tons worth $1.3 billion.4e7a9c25-dc8f-4b57-b72b-adafed7627df\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/alaska/finding/ocean-temp-chem-affect-fisheries.yaml identifier: ocean-temp-chem-affect-fisheries ordinal: 4 process: "A central component of the assessment process was the Alaska Regional Climate assessment workshop that was held September 12-15, 2012, in Anchorage with approximately 20 attendees; it began the process leading to a foundational Technical Input Report (TIR).6e174e7d-28f7-4ce4-9141-c378d82b4f53 The report consists of 148 pages of text, 45 figures, 8 tables, and 27 pages of references. Public and private citizens or institutions were consulted and engaged in its preparation and expert review by the various agencies and non-governmental organizations (NGOs) represented by the 11-member TIR writing team. The key findings of the report were presented at the Alaska Forum on the Environment and in a regularly scheduled, monthly webinar by the Alaska Center for Climate Assessment and Policy, with feedback then incorporated into the report.\r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences. These included careful expert review of the foundational TIR6e174e7d-28f7-4ce4-9141-c378d82b4f53 and of approximately 85 additional technical inputs provided by the public, as well as the other published literature and professional judgment. These discussions were followed by expert deliberation of draft key messages by the writing team in a face-to-face meeting before each key message was selected for inclusion in the Report. These discussions were supported by targeted consultation with additional experts by the lead author of each message, and they were based on criteria that help define “key vulnerabilities” (Ch. 26: Decision Support)." report_identifier: nca3 statement: 'Current and projected increases in Alaska’s ocean temperatures and changes in ocean chemistry are expected to alter the distribution and productivity of Alaska’s marine fisheries, which lead the U.S. in commercial value.' uncertainties: "Important new evidence confirmed many of the findings from a prior Alaska assessment (http://nca2009.globalchange.gov/alaska), which informed the 2009 NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a \r\nThe new evidence included results from improved models and updated observational data. The assessment included insights from stakeholders collected in a series of distributed engagement meetings that confirm the relevance and significance of the key message for local decision-makers. \r\nA key uncertainty is what the actual impacts of rising temperatures and changing ocean chemistry, including an increase in ocean acidification, will be on a broad range of marine biota and ecosystems. More monitoring is needed to document the extent and location of changes. Additional research is needed to assess how those changes will affect the productivity of key fishery resources and their food and prey base.\r\n" uri: /report/nca3/chapter/alaska/finding/ocean-temp-chem-affect-fisheries url: ~ - chapter_identifier: alaska confidence: 'There is high confidence that cumulative effects of climate change in Alaska strongly affect Native communities, which are highly vulnerable to these rapid changes but have a deep cultural history of adapting to change' evidence: "The key message and supporting chapter text summarize extensive evidence documented in the Alaska Technical Input Report.6e174e7d-28f7-4ce4-9141-c378d82b4f53 Technical input reports (85) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input. \r\nEvidence exists in recorded local observational accounts as well as in the peer-reviewed scientific literature of the cumulative effects of climate-related environmental change on Native communities in Alaska; these effects combine with other socioeconomic stressors to strain rural Native communities (Ch. 12: Indigenous Peoples).0a6d16f1-2362-46a1-8bfa-622dc2a43268,c26ea745-0499-488b-abdd-5599688deaaf,2e959d54-a5b5-49e2-8b87-eb5d6afb0e5a,c79a2225-9c80-4a6a-932e-73d4f8c499e4 Increasing attention to impacts of climate change is revealing new aspects, such as impacts to health and hunter safety (for example, Baffrey and Huntington 2010; Brubaker et al. 201193caee88-a37f-47dc-9b76-4351c6f122f5,a09df4b5-c276-4f3f-a251-c6dfd75cefe7). There is also strong evidence for the cultural adaptive capacity of these communities and peoples over time.6d7cc16a-7168-46d1-b22b-75244d6bc079,6ca055db-9671-4dbc-9d65-aa72ac9e9510,d46dee37-df23-4446-98de-f00d606317b6,c19771cd-e002-4973-ad8f-8ead63eb1d83,588b8649-ccfe-4107-b615-477cf05db8d7\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/alaska/finding/climate-change-affects-alaska-native.yaml identifier: climate-change-affects-alaska-native ordinal: 5 process: "A central component of the assessment process was the Alaska Regional Climate assessment workshop that was held September 12-15, 2012, in Anchorage with approximately 20 attendees; it began the process leading to a foundational Technical Input Report (TIR).6e174e7d-28f7-4ce4-9141-c378d82b4f53 The report consists of 148 pages of text, 45 figures, 8 tables, and 27 pages of references. Public and private citizens or institutions were consulted and engaged in its preparation and expert review by the various agencies and non-governmental organizations (NGOs) represented by the 11-member TIR writing team. The key findings of the report were presented at the Alaska Forum on the Environment and in a regularly scheduled, monthly webinar by the Alaska Center for Climate Assessment and Policy, with feedback then incorporated into the report.\r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences. These included careful expert review of the foundational TIR6e174e7d-28f7-4ce4-9141-c378d82b4f53 and of approximately 85 additional technical inputs provided by the public, as well as the other published literature and professional judgment. These discussions were followed by expert deliberation of draft key messages by the writing team in a face-to-face meeting before each key message was selected for inclusion in the Report. These discussions were supported by targeted consultation with additional experts by the lead author of each message, and they were based on criteria that help define “key vulnerabilities” (Ch. 26: Decision Support)." report_identifier: nca3 statement: 'The cumulative effects of climate change in Alaska strongly affect Native communities, which are highly vulnerable to these rapid changes but have a deep cultural history of adapting to change.' uncertainties: "Important new evidence confirmed many of the findings from a prior Alaska assessment (http://nca2009.globalchange.gov/alaska), which informed the 2009 NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a \r\nThe precise mechanisms by which climate change affects Native communities are poorly understood, especially in the context of rapid social, economic, and cultural change. Present day responses to environmental change are poorly documented. More research is needed on the ways that Alaska Natives respond to current biophysical climate change and to the factors that enable or constrain contemporary adaptation.\r\nAlaska Native communities are already being affected by climate-induced changes in the physical and biological environment, from coastal erosion threatening the existence of some communities, to alterations in hunting, fishing, and gathering practices that undermine the intergenerational transfer of culture, skill, and wisdom. At the same time, these communities have a long record of adaptation and flexibility. Whether such adaptability is sufficient to address the challenges of climate change depends both on the speed of climate-induced changes and on the degree to which Native communities are supported rather than constrained in the adaptive measures they need to make.0a6d16f1-2362-46a1-8bfa-622dc2a43268\r\n" uri: /report/nca3/chapter/alaska/finding/climate-change-affects-alaska-native url: ~ - chapter_identifier: hawaii confidence: There is very high confidence that ocean acidification and decreased aragonite saturation is taking place and is projected to continue. There is high confidence that ocean warming is taking place and is projected to continue; there is medium confidence that the thermal anomalies will lead to continued coral bleaching and coral disease outbreaks. evidence: "The key message was chosen based on input from the extensive evidence documented in the Hawai‘i Technical Input Report7350d7b3-6e95-4375-ba23-26756b441fc2 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nOcean warming: There is ample evidence that sea-surface temperatures have already risen throughout the region based on clear observational data, with improved data with the advent of satellite and in situ (ARGO & ship-based) data.05b4968a-410a-43f0-b668-b96c5af0373c Assessment of the literature for the region by other governmental bodies (such as Australian Bureau of Meteorology [ABOM] and the Commonwealth Scientific and Industrial Research Organization [CSIRO]) point to continued increases under both B1 and A2 scenarios.a639a8f6-3355-43d7-ab21-ef29364db75a \r\nOcean acidification: Globally, the oceans are currently absorbing about a quarter of the carbon dioxide emitted to the atmosphere annually, and becoming more acidic as a result (Ch. 2: Our Changing Climate, Key Message 12). Historical and current observations of aragonite saturation state (Ωar) for the Pacific Ocean show a decrease from approximately 4.9 to 4.8 in the Central North Pacific (Hawaiian Islands); in the Western North Pacific (Republic of Marshall Islands, Commonwealth of Northern Mariana Islands, Federated States of Micronesia, Republic of Palau, Guam), it has declined from approximately 4.5 to 3.9 in 2000, and to 4.1 in the Central South Pacific (American Samoa)(this chapter: Figure 23.3; Ch. 24: Oceans and Marine Resources).1ee9bb2b-9b22-48f0-b540-f942ccfd9c71 Projections from CMIP3 models indicate the annual maximum aragonite saturation state will reach values below 3.5 by 2035 in the waters of the Republic of the Marshall Islands (RMI), by 2030 in the Federated States of Micronesia (FSM), by 2040 in Palau, and by 2060 around the Samoan archipelago. These values are projected to continue declining thereafter.7350d7b3-6e95-4375-ba23-26756b441fc2 The recently published Reefs at Risk Revisited3d9112b9-6aa1-4614-9599-6966c9591ef9 estimates aragonite saturation state (as an indicator of ocean acidification) for CO2 stabilization levels of 380 ppm, 450 ppm, and 500 ppm, which correspond approximately to the years 2005, 2030, and 2050 under the A1B emissions scenario (which assumes similar emissions to the A2 scenario through 2050 and a slow decline thereafter) (Figure 4.4 from Keener et al. 20127350d7b3-6e95-4375-ba23-26756b441fc2). \r\nBleaching events: These have been well-documented in extensive literature worldwide due to increasing temperatures, with numerous studies in Hawai‘i and the Pacific Islands.ada58825-78cb-47be-a121-d5553c7e2870,f41beadd-748c-4117-a3b4-768138622179,745d74fa-44f3-4eaa-83b7-feb3743b9046 \r\nDisease outbreaks: Reports of coral diseases have been proliferating in the past years,9e0aded6-29e7-4d1c-a3fe-f0c5c750cd17,03f1ed25-ab43-4ab2-b13d-3358cc2e2e62,b15c3b47-5e74-4a10-ac4d-f61d17dd376b but few have currently been adequately described, with causal organisms identified (for example, fulfill Koch’s Postulates). \r\nReduced growth: There is abundant evidence from laboratory experiments that lower seawater pH reduces calcification rates in marine organisms (for example, Feely et al. 20091ee9bb2b-9b22-48f0-b540-f942ccfd9c71). However, actual measurements on the effects of ocean acidification on coral reef ecosystems in situ or in complex mesocosms are just now becoming available, and these measurements show that there are large regional and diel variability in pH and pCO2.3da133aa-972c-4f41-b43c-347f202a8554 The role of diel and regional variability on coral reef ecosystems requires further investigation.\r\nDistribution patterns of coastal and ocean fisheries: Evidence of the effects of ocean acidification on U.S. fisheries in Hawai‘i and the Pacific Islands is currently limited (Lehodey et al. 2011)1f38f63f-a854-44c5-8ebe-b8ec718bdf70 but there is accumulating evidence for ecosystem impacts. \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/hawaii/finding/ocean-warming-acidity-affect-fish.yaml identifier: ocean-warming-acidity-affect-fish ordinal: 1 process: "A central component of the assessment process was convening three focus area workshops as part of the Pacific Islands Regional Climate Assessment (PIRCA). The PIRCA is a collaborative effort aimed at assessing the state of climate knowledge, impacts, and adaptive capacity in Hawai‘i and the U.S. Affiliated Pacific Islands. These workshops included representatives from the U.S. federal agencies, universities, as well as international participants from other national agencies and regional organizations. The workshops led to the formulation of a foundational Technical Input Report (TIR).7350d7b3-6e95-4375-ba23-26756b441fc2 The report consists of nearly 140 pages, with almost 300 references, and was organized into 5 chapters by 11 authors. \r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences that permitted a careful review of the foundational TIR7350d7b3-6e95-4375-ba23-26756b441fc2 and of approximately 23 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. These discussions included a face-to-face meeting held on July 9, 2012. These discussions were supported by targeted consultation among the lead and contributing authors of each message. There were several iterations of review and comment on draft key messages and associated content." report_identifier: nca3 statement: 'Warmer oceans are leading to increased coral bleaching events and disease outbreaks in coral reefs, as well as changed distribution patterns of tuna fisheries. Ocean acidification will reduce coral growth and health. Warming and acidification, combined with existing stresses, will strongly affect coral reef fish communities. ' uncertainties: "New information: Since the 2009 National Climate Assessment,e251f590-177e-4ba6-8ed1-6f68b5e54c8a considerable effort has been employed to understand the impacts of ocean acidification (OA) on marine ecosystems, including recent ecosystem-based efforts.4b4c5af2-fce0-4c54-a098-6ea277602621,1f38f63f-a854-44c5-8ebe-b8ec718bdf70 Studies of OA impacts on organisms has advanced considerably, with careful chemistry using worldwide standard protocols making inroads into understanding a broadening range of organisms. \r\nHowever, predicting the effect of ocean acidification on marine organisms and marine coral reef ecosystems remains the key issue of uncertainty. The role of community metabolism and calcification in the face of overall reduction in aragonite saturation state must be investigated. \r\nUnderstanding interactions between rising temperatures and OA remains a challenge. For example, high temperatures simultaneously cause coral bleaching, as well as affect coral calcification rates, with both impacts projected to increase in the future. \r\n" uri: /report/nca3/chapter/hawaii/finding/ocean-warming-acidity-affect-fish url: ~ - chapter_identifier: hawaii confidence: 'Freshwater systems are inherently fragile in many Pacific Islands. Historical observations show strong evidence of a decreasing trend for rainfall in Hawai‘i and many other Pacific Islands (Ch. 2: Our Changing Climate).7350d7b3-6e95-4375-ba23-26756b441fc2 There is abundant and definitive evidence that air temperature has increased and will continue to increase. All of the scientific approaches to detecting sea level rise come to the conclusion that a warming planet will result in higher sea levels. Based on the evidence base and remaining uncertainties, we have high confidence in the key message. ' evidence: "There is abundant and definitive evidence that air temperature has increased and is projected to continue to increase over the entire region,a639a8f6-3355-43d7-ab21-ef29364db75a,c70e33c2-49f5-499b-ac5a-a63cbf83b698,d28411c8-f40c-446a-b6a9-2dd1c844deea,dde62a65-2752-4101-bd95-cfcc0e89dc66 as there is globally (Ch. 2: Our Changing Climate, Key Message 3).\r\nIn Hawai‘i and the Central North Pacific (CNP), projected annual surface air temperature increases are 1.0°F to 2.5°F by 2035, relative to 1971-2000.634424c9-14a9-4133-9ed6-8948faa0b11e,eff5ce0d-c403-455b-9358-98be45351c7b In the Western North Pacific (WNP), the projected increases are 2.0°F to 2.3°F by 2030, 6.1°F to 8.5°F by 2055, and 4.9°F to 9.2°F by 2090.a639a8f6-3355-43d7-ab21-ef29364db75a In the central South Pacific (CSP), projected annual surface air temperature increases are 1.1°F to 1.3°F by 2030, 1.8°F to 2.5°F by 2055, and 2.5°F to 4.9°F by 2090.a639a8f6-3355-43d7-ab21-ef29364db75a (Please note that the islands that comprise the U.S. Pacific Islands Region are shown in Figure 23.1).\r\nIn Hawai‘i, mean precipitation, average stream discharge, and stream baseflow have been trending downward for nearly a century, especially in recent decades and with high variability related to El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO).8e3247e0-fd15-4c29-8ed4-4aafd9c8660f,9a5c2112-9d46-45f0-b97a-64a8a8c574b1,a7bc5b58-4952-4499-9285-af61da992262 For the WNP, a decline of 15% in annual rainfall has been observed in the eastern-most islands in the Micronesia region and slight upward trends in precipitation have been seen for the western-most islands, with high ENSO-related variability.a639a8f6-3355-43d7-ab21-ef29364db75a In American Samoa, no trends in average rainfall are apparent based on the very limited available data.a639a8f6-3355-43d7-ab21-ef29364db75a,ab312e6f-70ad-4653-ac9f-78ce77e4ded7 \r\nFor the region as a whole, models disagree about projected changes in precipitation. Mostly models predict increases in mean annual rainfall and suggest a slight dry season decrease and wet season increase in precipitation.a639a8f6-3355-43d7-ab21-ef29364db75a However, based on statistical downscaling, one study2aea4790-7e38-4922-bc92-d20c06d23b7d projected a 5% to 10% reduction in precipitation for the wet season and a 5% increase in the dry season for Hawai‘i by the end of this century.\r\nOn most islands, increased temperatures coupled with decreased rainfall and increased drought will reduce the amount of freshwater for drinking and crop irrigation.6eb1ee99-0b99-452a-a8cb-48b961fd4ac5,ca2a1adf-0f5a-4838-aa81-fc0c44f50369,c600849a-ed32-4109-a103-1571e136f0b6 Atolls will be particularly vulnerable due to their low elevation, small land mass, geographic isolation, and limited potable water sources and agricultural resources.15a85bcf-1235-4258-860c-24948df66935 The situation will also be exacerbated by the increased incidence of intrusion of saltwater from the ocean during storms as the mean sea level rises over time (Key Message 4, this chapter; Ch. 2: Our Changing Climate, Key Message 10).7350d7b3-6e95-4375-ba23-26756b441fc2 \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/hawaii/finding/freshwater-supplies-more-limited.yaml identifier: freshwater-supplies-more-limited ordinal: 2 process: "A central component of the assessment process was convening three focus area workshops as part of the Pacific Islands Regional Climate Assessment (PIRCA). The PIRCA is a collaborative effort aimed at assessing the state of climate knowledge, impacts, and adaptive capacity in Hawai‘i and the U.S. Affiliated Pacific Islands. These workshops included representatives from the U.S. federal agencies, universities, as well as international participants from other national agencies and regional organizations. The workshops led to the formulation of a foundational Technical Input Report (TIR).7350d7b3-6e95-4375-ba23-26756b441fc2 The report consists of nearly 140 pages, with almost 300 references, and was organized into 5 chapters by 11 authors. \r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences that permitted a careful review of the foundational TIR7350d7b3-6e95-4375-ba23-26756b441fc2 and of approximately 23 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. These discussions included a face-to-face meeting held on July 9, 2012. These discussions were supported by targeted consultation among the lead and contributing authors of each message. There were several iterations of review and comment on draft key messages and associated content." report_identifier: nca3 statement: 'Freshwater supplies are already constrained and will become more limited on many islands. Saltwater intrusion associated with sea level rise will reduce the quantity and quality of freshwater in coastal aquifers, especially on low islands. In areas where precipitation does not increase, freshwater supplies will be adversely affected as air temperature rises.' uncertainties: "Climate change impacts on freshwater resources in the Pacific Islands region will vary because of differing island size and height, which affect water storage capability and susceptibility to coastal inundation. The impacts will also vary because of natural phase variability (for example, ENSO and PDO) in precipitation and storminess (tropical and extra-tropical storms) as well as long-term trends, both strongly influenced by geographic location.\r\nClimate model simulations produce conflicting assessments as to how the tropical Pacific atmospheric circulation will respond in the future to climate change.\r\n" uri: /report/nca3/chapter/hawaii/finding/freshwater-supplies-more-limited url: ~ - chapter_identifier: hawaii confidence: 'Terrestrial and marine ecosystems are already being impacted by local stressors, such as coastal development, land-based sources of pollution, and invasive species.7350d7b3-6e95-4375-ba23-26756b441fc2,3d9112b9-6aa1-4614-9599-6966c9591ef9 There is abundant and definitive evidence that air temperature has increased and will continue to increase. Historical observations show strong evidence of a decreasing trend for rainfall in Hawai‘i and many other Pacific Islands.7350d7b3-6e95-4375-ba23-26756b441fc2 Given the evidence base and remaining uncertainties, confidence is high in this key message. ' evidence: "In Hawai‘i and the Central North Pacific (CNP), projected annual surface air temperature increases are 1.0°F to 2.5°F by 2035, relative to 1971-2000.634424c9-14a9-4133-9ed6-8948faa0b11e,eff5ce0d-c403-455b-9358-98be45351c7b In the Western North Pacific (WNP), the projected increases are 2.0°F to 2.3°F by 2030, 6.1°F to 8.5°F by 2055, and 4.9°F to 9.2°F by 2090.a639a8f6-3355-43d7-ab21-ef29364db75a In the Central South Pacific (CSP), projected annual surface air temperature increases are 1.1°F to 1.3°F by 2030, 1.8°F to 2.5°F by 2055, and 2.5°F to 4.9°F by 2090.a639a8f6-3355-43d7-ab21-ef29364db75a In Hawai‘i the rate of increase has been greater at high elevations.c70e33c2-49f5-499b-ac5a-a63cbf83b698 (Please note that the islands that comprise the U.S. Pacific Islands Region are shown in Figure 23.1). \r\nIn Hawai‘i mean precipitation, average stream discharge, and stream baseflow have been trending downward for nearly a century, especially in recent decades and with high ENSO and PDO-related variability.8e3247e0-fd15-4c29-8ed4-4aafd9c8660f,9a5c2112-9d46-45f0-b97a-64a8a8c574b1,a7bc5b58-4952-4499-9285-af61da992262,692a84a8-b5db-4ab2-82bf-e5244a63402a Projects based on statistical downscaling2aea4790-7e38-4922-bc92-d20c06d23b7d suggest the most likely precipitation scenario for Hawai‘i for the 21st century to be a 5% to 10% reduction for the wet season and a 5% increase in the dry season.\r\nOn high islands like Hawai‘i, decreases in precipitation and baseflowa7bc5b58-4952-4499-9285-af61da992262 are already indicating that there will be impacts on freshwater ecosystems and aquatic species, and on water-intensive sectors such as agriculture and tourism.\r\nHawaiian high-elevation alpine ecosystems on Hawai‘i and Maui islands are already beginning to show strong signs of increased drought and warmer temperatures.d1588faa-2aa9-4cdd-ba04-489c464fca3f Demographic data for the Haleakalā silversword, a unique (endemic to upper Haleakalā volcano) and integral component of the alpine ecosystem in Haleakalā National Park, Maui, have recorded a severe decline in plant numbers over the past two decades.04621537-01f9-459c-ac49-b531db72c3f2 Many of Hawai‘i’s endemic forest birds, marvels of evolution largely limited to high-elevation forests by predation and disease, are increasingly vulnerable as rising temperatures allow the disease-vectoring mosquitoes to thrive upslope and thereby reduce the extent of safe bird habitat.85ce98bb-ac2b-47a8-acf9-75007bcde4b9,73af9d00-a709-4b04-975e-e3f90431695a\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/hawaii/finding/increasing-temps-stress-plants-animals.yaml identifier: increasing-temps-stress-plants-animals ordinal: 3 process: "A central component of the assessment process was convening three focus area workshops as part of the Pacific Islands Regional Climate Assessment (PIRCA). The PIRCA is a collaborative effort aimed at assessing the state of climate knowledge, impacts, and adaptive capacity in Hawai‘i and the U.S. Affiliated Pacific Islands. These workshops included representatives from the U.S. federal agencies, universities, as well as international participants from other national agencies and regional organizations. The workshops led to the formulation of a foundational Technical Input Report (TIR).7350d7b3-6e95-4375-ba23-26756b441fc2 The report consists of nearly 140 pages, with almost 300 references, and was organized into 5 chapters by 11 authors. \r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences that permitted a careful review of the foundational TIR7350d7b3-6e95-4375-ba23-26756b441fc2 and of approximately 23 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. These discussions included a face-to-face meeting held on July 9, 2012. These discussions were supported by targeted consultation among the lead and contributing authors of each message. There were several iterations of review and comment on draft key messages and associated content." report_identifier: nca3 statement: 'Increasing temperatures, and in some areas reduced rainfall, will stress native Pacific Island plants and animals, especially in high-elevation ecosystems with increasing exposure to invasive species, increasing the risk of extinctions.' uncertainties: "Climate change impacts in the Pacific Islands region will vary because of differing island size and height. The impacts will also vary because of natural phase variability (for example, El Niño-Southern Oscillation and Pacific Decadal Oscillation) in precipitation and storminess (tropical and extra-tropical storms) as well as long-term trends, both strongly influenced by geographic location.\r\nClimate model simulations produce conflicting assessments as to how the tropical Pacific atmospheric circulation will respond in the future to climate change.7350d7b3-6e95-4375-ba23-26756b441fc2,a639a8f6-3355-43d7-ab21-ef29364db75a\r\nClimate change ecosystem response is poorly understood.7350d7b3-6e95-4375-ba23-26756b441fc2 \r\n" uri: /report/nca3/chapter/hawaii/finding/increasing-temps-stress-plants-animals url: ~ - chapter_identifier: hawaii confidence: "Evidence for global sea level rise is strong (Ch. 25: Coasts; Ch. 2: Our Changing Climate). Confidence is therefore very high. Modeling studies have yielded conflicting results as to how ENSO and other climate modes will vary in the future. As a result, there is low confidence in the prediction of future climate states and their subsequent influence on regional sea level.6fd7abfe-17d7-49a9-bc90-bf85fa4041d3 Recent assessments of future extreme conditions generally place low confidence on region-specific projections of future storminess.5138b20c-7049-433e-a1ec-24417cccd3c2\r\nFor aspects of the key message concerning impacts, confidence is high. \r\n" evidence: "Description of evidence base\r\nAll of the scientific approaches to detecting sea level rise come to the conclusion that a warming planet will result in higher sea levels. Recent studies give higher sea level rise projections than those projected in 2007 by the Intergovernmental Panel on Climate Changef83b5613-7609-4799-ab8c-c2a41bdc924c for the rest of this century (Ch. 2: Our Changing Climate, Key Message 10).7b7ffcb0-766c-43b3-ac22-db29fbffef71\r\nSea level is rising and is expected to continue to rise. Over the past few decades, global mean sea level, as measured by satellite altimetry, has been rising at an average rate of twice the estimated rate for the previous century, based on tide gauge measurements,7b7ffcb0-766c-43b3-ac22-db29fbffef71 with models suggesting that global sea level will rise significantly over the course of this century. Regionally, the highest increases have been observed in the western tropical Pacific.cc032910-1557-4eb7-ac24-d183ad14a8da,cef33c87-edde-4bbd-bd8c-325ae895cace However, the current high rates of regional sea level rise in the western tropical Pacific are not expected to persist, as regional sea level will fall in response to a change in phase of natural variability.6fd7abfe-17d7-49a9-bc90-bf85fa4041d3 Regional variations in sea level at interannual and interdecadal time scales are generally attributed to changes in prevailing wind patterns associated with El Niño-Southern Oscillation (ENSO) as well as the Pacific Decadal Oscillation (PDO) and low frequency components of the Southern Oscillation Index (SOI).1c00ae8a-ba2d-464d-9f3a-a353404c4baf,0fd3c22b-8b49-472d-959c-92c4742ac794,ca7d7630-6134-49a5-b933-7de9417ace1b \r\nFor the region, extreme sea level events generally occur when high tides combine with some non-tidal residual change in water level. In the major typhoon zones (Guam and Commonwealth of the Northern Mariana Islands), storm-driven surges can cause coastal flooding and erosion regardless of tidal state. Wave-driven inundation events are a major concern for all islands in the region. At present, trends in extreme levels tend to follow trends in mean sea level.\r\nIncreasing mean water levels and the possibility of more frequent extreme water level events, and their manifestation as flooding and erosion, will threaten coastal structures and property, groundwater reservoirs, harbor operations, airports, wastewater systems, sandy beaches, coral reef ecosystems, and other social and economic resources. Impacts will vary with location, depending on how natural sea level variability combines with modest increases of mean levels.6fd7abfe-17d7-49a9-bc90-bf85fa4041d3\r\nOn low-lying atolls, critical public facilities and infrastructure as well as private commercial and residential property are especially vulnerable.6fd7abfe-17d7-49a9-bc90-bf85fa4041d3 Agricultural activity will also be affected, as sea level rise decreases the land area available for farming6aa21d2e-f2dc-45b6-9815-bf1132eba02c and episodic inundation increases salinity of groundwater resources. Impacts to the built environment on low-lying portions of high islands will be much the same as those experienced on low islands. Islands with more developed built infrastructure will experience more economic impacts from tourism loss. One report stated: “Our analyses estimate that nearly $2.0 billion in overall visitor expenditures could be lost annually due to a complete erosion of Waikīkī Beach.”a02dcc41-9b79-4564-89af-fcdad699e5d3\r\nCoastal and nearshore environments (sandy beaches, shallow coral reefs, seagrass beds, intertidal flats, and mangrove forests) and the vegetation and terrestrial animals in these systems will progressively be affected as sea level rise and high wave events alter atoll island size and shape and reduce habitat features necessary for survival. Based on extrapolation from results in American Samoa, sea level rise could cause future reductions of 10%–20% of total regional mangrove area over the next century.da5a93c8-9c73-45f7-966f-5b1970fec7a4 Further, atoll-breeding Pacific seabirds will lose large segments of their breeding populations7350d7b3-6e95-4375-ba23-26756b441fc2 The report consists of nearly 140 pages, with almost 300 references, and was organized into 5 chapters by 11 authors. \r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences that permitted a careful review of the foundational TIR7350d7b3-6e95-4375-ba23-26756b441fc2 and of approximately 23 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. These discussions included a face-to-face meeting held on July 9, 2012. These discussions were supported by targeted consultation among the lead and contributing authors of each message. There were several iterations of review and comment on draft key messages and associated content." report_identifier: nca3 statement: 'Rising sea levels, coupled with high water levels caused by tropical and extra-tropical storms, will incrementally increase coastal flooding and erosion, damaging coastal ecosystems, infrastructure, and agriculture, and negatively affecting tourism. ' uncertainties: 'Sea levels in the Pacific Ocean will continue to rise with global sea level. Models provide a range of predictions, with some suggesting that global warming may raise global sea level considerably over the course of this century. The range of predictions is large due in part to unresolved physical understanding of various processes, notably ice sheet dynamics. Changes in prevailing wind patterns associated with natural climate cycles such as ENSO and the PDO affect regional variations in sea level at interannual and interdecadal time scales. Sea level at specific locales will continue to respond to changes in phase of these natural climate cycles. The current high rates of regional sea level rise in the western tropical Pacific are not expected to persist over time, falling once the trade winds begin to weaken. Future wind wave conditions are difficult to project with confidence given the uncertainties regarding future storm conditions. ' uri: /report/nca3/chapter/hawaii/finding/rising-sea-water-damages url: ~ - chapter_identifier: hawaii confidence: 'Evidence for climate change and impacts is strong, but highly variable from location to location. One can be highly confident that climate change will continue to pose varied threats in the region. Adaptive capacity is also highly variable among the islands, so the resulting situation will play out differently in different places. Confidence is therefore medium. ' evidence: "Climate change threatens communities, cultures, and ecosystems of the Pacific Islands both directly through impact on food and water security, for example, as well as indirectly through impacts on economic sectors including fisheries and tourism. \r\nOn most islands, increased temperatures, coupled with decreased rainfall and increased drought, will lead to an additional need for freshwater resources for drinking and crop irrigation.6eb1ee99-0b99-452a-a8cb-48b961fd4ac5,ca2a1adf-0f5a-4838-aa81-fc0c44f50369,c600849a-ed32-4109-a103-1571e136f0b6 This is particularly important for locations in the tropics and subtropics where observed data and model projections suggest that, by the end of this century, the average growing season temperatures will exceed the most extreme seasonal temperatures recorded from 1900 to 2006. Atolls will be particularly vulnerable due to their low elevation, small land mass, geographic isolation, and limited potable water sources and agricultural resources.15a85bcf-1235-4258-860c-24948df66935 The situation will also be exacerbated by the increased incidence of intrusion of saltwater from the ocean during storms as the mean sea level rises over time. These are but part of a cascade of impacts that will increase the pressures on, and threats to, the social and ecosystem sustainability of these island communities.dcfdf5ac-81c1-4eed-ae50-258a9086b9b5 On high islands like Hawai‘i, decreases in precipitation and baseflowa7bc5b58-4952-4499-9285-af61da992262 are already indicating that there will be impacts on freshwater ecosystems and aquatic species and on water-intensive sectors such as agriculture and tourism.\r\nIncreasing mean oceanic and coastal water levels and the possibility of more frequent extreme water level events with flooding and erosion, will escalate the threat to coastal structures and property, groundwater reservoirs, harbor operations, airports, wastewater systems, sandy beaches, coral reef ecosystems, and other social and economic resources. Impacts will vary with location depending on how natural sea level variability combines with modest increases of mean levels.6fd7abfe-17d7-49a9-bc90-bf85fa4041d3 On low-lying atolls, critical public facilities and infrastructure as well as private commercial and residential property are especially vulnerable. Agricultural activity will also be affected, as sea level rise decreases the land area available for farming6aa21d2e-f2dc-45b6-9815-bf1132eba02c and episodic inundation increases salinity of groundwater resources. \r\nWith respect to cultural resources, impacts will extend from the loss of tangible artifacts and structures06f42044-ef11-45ad-8df5-4eabf2cd4e2f to the intangible loss of a land base and the cultural traditions that are associated with it.11cbe03d-0255-4abb-9b77-498e9ebd4500\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/hawaii/finding/effects-of-human-island-migration.yaml identifier: effects-of-human-island-migration ordinal: 5 process: "A central component of the assessment process was convening three focus area workshops as part of the Pacific Islands Regional Climate Assessment (PIRCA). The PIRCA is a collaborative effort aimed at assessing the state of climate knowledge, impacts, and adaptive capacity in Hawai‘i and the U.S. Affiliated Pacific Islands. These workshops included representatives from the U.S. federal agencies, universities, as well as international participants from other national agencies and regional organizations. The workshops led to the formulation of a foundational Technical Input Report (TIR).7350d7b3-6e95-4375-ba23-26756b441fc2 The report consists of nearly 140 pages, with almost 300 references, and was organized into 5 chapters by 11 authors. \r\nThe chapter author team engaged in multiple technical discussions via regular teleconferences that permitted a careful review of the foundational TIR7350d7b3-6e95-4375-ba23-26756b441fc2 and of approximately 23 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. These discussions included a face-to-face meeting held on July 9, 2012. These discussions were supported by targeted consultation among the lead and contributing authors of each message. There were several iterations of review and comment on draft key messages and associated content." report_identifier: nca3 statement: 'Mounting threats to food and water security, infrastructure, and public health and safety are expected to lead to increasing human migration from low to high elevation islands and continental sites, making it increasingly difficult for Pacific Islanders to sustain the region’s many unique customs, beliefs, and languages.' uncertainties: 'Whenever appraising threats to human society, it is uncertain the degree to which societies will successfully adapt to limit impact. For island communities, though, the ability to migrate is very limited, and the ability to adapt is especially limited. Depending on the scale and distance of the migration, a variety of challenges face the migrants and the communities receiving them. Migrants need to establish themselves in their new community, find employment, and access services, while the receiving community’s infrastructure, labor market, commerce, natural resources, and governance structures need to absorb a sudden burst of population growth.' uri: /report/nca3/chapter/hawaii/finding/effects-of-human-island-migration url: ~ - chapter_identifier: oceans-marine-resources confidence: 'Confidence that the ocean is warming and acidifying, and that sea level is rising is very high. Changes in other physical and chemical properties such as ocean circulation, wave heights, oxygen minimums, and salinity are of medium confidence. For ecosystem changes, there is high confidence that these are occurring and will persist and likely grow in the future, though the details of these changes are highly geographically variable. ' evidence: "The key message is supported by extensive evidence documented in Sections 2 and 3 of the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and in the additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nRelevant and recent peer-reviewed publications,11dc1346-c458-4cf2-a3c1-f75b60c337cb,c0c83a69-2a4b-466b-825b-75104629014e,ade3fd09-603e-4fae-b252-1a4142392ea0,9f1fa4b6-2d4d-414a-8cee-4b6e589753bb,88eb1d21-c245-468e-9508-33f3beebe215 including many others that are cited therein, describe evidence that ocean temperature has risen over the past century. This evidence base includes direct and indirect temperature measurements, paleoclimate records, and modeling results.\r\nThere are also many relevant and recent peer-reviewed publications describing changes in physical and chemical ocean properties that are underway due to climate change.ec529b7a-dce4-48fe-9a6c-e118ca810835,24efff6a-9043-44c0-b7a2-fc4ff2461576,d17a7c52-86c2-4dfc-9328-d6e3df410daf \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/increased-ocean-temp-impacts.yaml identifier: increased-ocean-temp-impacts ordinal: 1 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: 'The rise in ocean temperature over the last century will persist into the future, with continued large impacts on climate, ocean circulation, chemistry, and ecosystems.' uncertainties: "Important new information since the last National Climate Assessmente251f590-177e-4ba6-8ed1-6f68b5e54c8a includes the latest update to a data set of ocean temperatures.9f1fa4b6-2d4d-414a-8cee-4b6e589753bb\r\nThere is accumulating new information on all of these points with regard to physical and chemical changes in the ocean and resultant impacts on marine ecosystems. Both measurements and model results are continuing to sharpen the picture. \r\nA significant area of uncertainty remains with regard to the region-by-region impacts of warming, acidification, and associated changes in the oceans. Regional and local conditions mean that impacts will not be uniform around the U.S. coasts or internationally. Forecasting of regional changes is still an area of very active research, though the overall patterns for some features are now clear. \r\nLarge-scale and recurring climate phenomena (such as the El Niño Southern Oscillation, the Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation) cause dramatic changes in biological productivity and ecosystem structure and make it difficult to discern climate-driven trends. \r\nCurrent time series of biological productivity are restricted to a handful of sites around the globe and to a few decades, and global, comprehensive satellite time series of ocean color are even shorter, beginning in 1997. Based on an analysis of different in situ datasets, one research group suggested a decline of 1% per year over the past century, but these findings may be an artifact of limited data and have been widely debated.d17a7c52-86c2-4dfc-9328-d6e3df410daf,973493c4-7e62-481c-91ce-abd7168bc05e However, the few in situ time series mostly indicate increases in biological productivity over the past 20 years, but with clear links to regional changes in climate.d17a7c52-86c2-4dfc-9328-d6e3df410daf \r\n" uri: /report/nca3/chapter/oceans-marine-resources/finding/increased-ocean-temp-impacts url: ~ - chapter_identifier: oceans-marine-resources confidence: 'Confidence is very high that carbon dioxide emissions to the atmosphere are causing ocean acidification, and high that this will alter marine ecosystems. The nature of those alterations is unclear, however, and predictions of most specific ecosystem changes have low confidence at present, but with medium confidence for coral reefs.' evidence: "The key message is supported by extensive evidence documented in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nNumerous references provide evidence for the increasing acidity (lower pH) of oceans around the world (Ch. 2: Our Changing Climate, Key Message 12).a36b4f01-c7d8-493d-b0dc-7f0f04f73b4b,c299055a-259d-4bd5-be87-1dbbba4174d4 \r\nThere is a rapid growth in peer-reviewed publications describing how ocean acidification will impact ecosystems,2f1dcb89-554b-42ed-86bd-2c6e6a5bb27e,e2d475bc-34fd-46f5-9f0a-17cbac654617 but to date evidence is largely based on studies of calcification rather than growth, reproduction, and survival of organisms. For these latter effects, available evidence is from laboratory studies in low pH conditions, rather than in situ observations.d3f2fc9b-6acf-48b0-b5d1-0f8c620e7f35,4b235b7f-7d25-4b2f-919d-89c3fa917803\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/ocean-acidity-increase-alters-marine.yaml identifier: ocean-acidity-increase-alters-marine ordinal: 2 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: 'The ocean currently absorbs about a quarter of human-caused carbon dioxide emissions to the atmosphere, leading to ocean acidification that will alter marine ecosystems in dramatic yet uncertain ways.' uncertainties: 'The interplay of environmental stressors may result in “surprises” where the synergistic impacts may be more deleterious or more beneficial than expected. Such synergistic effects create complexities in predicting the outcome of the interplay of stressors on marine ecosystems. Many, but not all, calcifying species are affected by increased acidity in laboratory studies. How those responses will cascade through ecosystems and food webs is still uncertain. Although studies are underway to expand understanding of ocean acidification on all aspects of organismal physiology, much remains to be learned. ' uri: /report/nca3/chapter/oceans-marine-resources/finding/ocean-acidity-increase-alters-marine url: ~ - chapter_identifier: oceans-marine-resources confidence: 'There is very high confidence that habitat and ecosystems are changing due to climate change, but that change is not unidirectional by any means. Distribution, abundance, and productivity changes are species and location dependent and may be increasing or decreasing in a complex pattern. ' evidence: "The key message is supported by extensive evidence documented in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nMany peer-reviewed publications3d9112b9-6aa1-4614-9599-6966c9591ef9,b78bfacb-e00f-4af6-8ad7-dff157f8b8b4,b09adbe5-6a17-4d3c-ab96-b3d9e306af67,f516a114-4604-4062-a1b3-e70a4cbbba9e describe threats to coral reefs induced by global change.\r\nThere are also many relevant and recent peer-reviewed publications006ce4db-d72c-400a-a409-c6a536e55664,128194f0-1295-4321-a7bf-a8dee1fc2247,d7265962-536c-4002-b3a7-1ed6e8841753,8b09bbe8-9f42-412e-a4d6-ef4889f56556,3f1b7fd7-3b1b-4b7f-8b68-802eddde7a27,c767db68-2732-424b-9dc6-e6bf94bc7a8e that discuss impacts on marine species and resources of habitat change that is induced by climate change. \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/marine-habitat-loss-and-expansion.yaml identifier: marine-habitat-loss-and-expansion ordinal: 3 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: 'Significant habitat loss will continue to occur due to climate change for many species and areas, including Arctic and coral reef ecosystems, while habitat in other areas and for other species will expand. These changes will consequently alter the distribution, abundance, and productivity of many marine species.' uncertainties: "Regional and local variation is, again, a major component of the remaining uncertainties. Different areas, habitats, and species are responding differently and have very different adaptive capacities. Those species that are motile will certainly respond differently, or at least at a different rate, by changing distribution and migration patterns, compared to species that do not move, such as corals. \r\nAlthough it is clear that some fish stocks are moving poleward and to deeper water, how far they will move and whether most species will move remains unclear. A key uncertainty is the extent to which various areas will benefit from range expansions of valuable species or increases in productivity, while other areas will suffer as species move away from previously productive areas. The loss of critically important habitat due to climate change will result in changes in species interactions that are difficult to predict. \r\n" uri: /report/nca3/chapter/oceans-marine-resources/finding/marine-habitat-loss-and-expansion url: ~ - chapter_identifier: oceans-marine-resources confidence: 'There is high confidence that disease outbreaks and levels are increasing, and that this increase is linked to increasing temperatures. Again, there is substantial local to regional variation but the overall pattern seems consistent. ' evidence: "The key message is supported by extensive evidence in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nAs noted in the chapter, the references document increased levels and ranges of disease coincident with rising temperatures.5a0265eb-17cf-4872-b96a-5b38e685cf66,07709e73-c331-4953-a578-909aa80ae86e,2dcec73a-c9eb-4f23-9182-ac6bd27e716c,5ab374b7-c974-45aa-9986-2aacb9ada5bb,8a3a7060-f48a-4744-9374-082f41569f4f,f6756660-773c-43d7-a595-77f6faececae \r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/sea-surface-temp-up-increase-disease.yaml identifier: sea-surface-temp-up-increase-disease ordinal: 4 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: 'Rising sea surface temperatures have been linked with increasing levels and ranges of diseases in humans and in marine life, including corals, abalones, oysters, fishes, and marine mammals.' uncertainties: 'The interactions among host, environment, and pathogen are complex, which makes it challenging to separate warming due to climate change from other causes of disease outbreaks in the ocean.' uri: /report/nca3/chapter/oceans-marine-resources/finding/sea-surface-temp-up-increase-disease url: ~ - chapter_identifier: oceans-marine-resources confidence: 'As with many other impacts of climate change, the evidence that change is occurring is very strong but the resultant impacts are still uncertain. For all of these human uses, and the associated costs and disruption, the evidence is suggestive and confidence medium on the effects of the ongoing changes in ocean conditions. ' evidence: "The key message is supported by extensive evidence documented in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nMany peer-reviewed publications describe the predicted impacts of climate change on tourism and recreation industries and their associated infrastructure.804b8cfd-5b1f-4a0f-b0df-6fac0742917a,5619eb6b-92e4-459f-9879-798c7ce99faf,43da51bd-b161-4454-8a9a-cefff6c0d3af\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/climate-change-affects-ocean-uses.yaml identifier: climate-change-affects-ocean-uses ordinal: 5 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: Climate changes that result in conditions substantially different from recent history may significantly increase costs to businesses as well as disrupt public access and enjoyment of ocean areas. uncertainties: 'Given the complexity of transportation, resource use and extraction, and leisure and tourism activities, there are large uncertainties in impacts in specific locales or for individual activities. Some businesses and communities may be able to adapt rapidly, others less so. Infrastructure impacts of climate change will also be an important part of the ability of businesses, communities, and the public to adapt. ' uri: /report/nca3/chapter/oceans-marine-resources/finding/climate-change-affects-ocean-uses url: ~ - chapter_identifier: oceans-marine-resources confidence: 'There is high confidence that adaptation planning will help mitigate the impacts of changing ocean conditions. But there is much work to be done to craft local solutions to the set of emerging issues in ocean and coastal areas. ' evidence: "The key message is supported by extensive evidence documented in the Oceans Technical Input Report018aba6e-7bff-4124-ae9a-f2521e683bd1 and additional technical inputs reports received as part of the Federal Register Notice solicitation for public input, as well as stakeholder engagement leading up to drafting the chapter. \r\nScenarios suggest that adjustments to fish harvest regimes can improve catch stability under increased climate variability. These actions could have a greater effect on biological and economic performance in fisheries than impacts due to warming over the next 25 years.1d6e1e85-9d87-423d-acb9-98021e7c0a49,9a6b5247-ea62-4f66-a840-0f1d00712573,6a870b46-c599-4bf3-8dcf-32067fdd8393\r\n" href: http://52.38.26.42:8080/report/nca3/chapter/oceans-marine-resources/finding/ocean-management-adaptations.yaml identifier: ocean-management-adaptations ordinal: 6 process: "A central component of the assessment process was the Oceans and Marine Resources Climate assessment workshop that was held January 23-24, 2012, at the National Oceanographic and Atmospheric Administration (NOAA) in Silver Spring, MD, and simultaneously, via web teleconference, at NOAA in Seattle, WA. In the workshop, nearly 30 participants took part in a series of scoping presentations and breakout sessions that began the process leading to a foundational Technical Input Report (TIR) entitled “Oceans and Marine Resources in a Changing Climate: Technical Input to the 2013 National Climate Assessment.”018aba6e-7bff-4124-ae9a-f2521e683bd1 The report, consisting of nearly 220 pages of text organized into 7 sections with numerous subsections and more than 1200 references, was assembled by 122 authors representing governmental agencies, non-governmental organizations, tribes, and other entities. \r\nThe chapter author team engaged in multiple technical discussions via teleconferences that permitted a careful review of the foundational TIR018aba6e-7bff-4124-ae9a-f2521e683bd1 and of approximately 25 additional technical inputs provided by the public, as well as the other published literature, and professional judgment. The chapter author team met at Conservation International in Arlington, VA on 3-4 May 2012 for expert deliberation of draft key messages by the authors, wherein each message was defended before the entire author team before the key message was selected for inclusion in the report. These discussions were supported by targeted consultation with additional experts by the lead author of each message to help define “key vulnerabilities.”" report_identifier: nca3 statement: 'In response to observed and projected climate impacts, some existing ocean policies, practices, and management efforts are incorporating climate change impacts. These initiatives can serve as models for other efforts and ultimately enable people and communities to adapt to changing ocean conditions.' uncertainties: 'Efforts are underway to enhance the development and deployment of science in support of adaptation, to improve understanding and awareness of climate-related risks, and to enhance analytic capacity to translate understanding into planning and management activities. While critical knowledge gaps exist, there is a wealth of climate- and ocean-related science pertinent to adaptation.018aba6e-7bff-4124-ae9a-f2521e683bd1' uri: /report/nca3/chapter/oceans-marine-resources/finding/ocean-management-adaptations url: ~ - chapter_identifier: coastal-zone confidence: 'Given the evidence base, the large quantity of infrastructure (water-related infrastructure, energy infrastructure, and the 60,000 miles of coastal roads) in the U.S. coastal zone, and the directional trend at least of sea level rise and runoff associated with heavy precipitation events, we have very high confidence that these types of infrastructure in the coastal zone are increasingly vulnerable' evidence: 'Coastal infrastructure is defined here to include buildings, roads, railroads, airports, port facilities, subways, tunnels, bridges, water supply systems, wells, sewer lines, pump stations, wastewater treatment plants, water storage and drainage systems, port facilities, energy production and transmission facilities on land and offshore, flood protection systems such as levees and seawalls, and telecommunication equipment. Lifelines are understood in the common usage of that term in hazards management. The key message and supporting text summarize extensive evidence documented in the coastal zone technical input reportfbb1a8af-292f-4fa4-9ed9-2724c65c5f29,207ddc2e-343a-4017-83e1-9ac70c02f723 as well as a technical input report on infrastructure.f0803451-5a89-474a-974f-99c13fdc725d Technical input reports (68) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input, along with the extant scientific literature. Additional evidence is provided in other chapters on hurricanes (Ch. 2: Our Changing Climate, Key Message 8), global sea level rise (Ch. 2: Our Changing Climate, Key Message 10), water supply vulnerabilities (Ch. 3: Water); key coastal transportation vulnerabilities (Ch. 5: Transportation), and energy-related infrastructure (Ch. 4: Energy). This key message focuses mainly on water supply and energy infrastructure and evacuation routes, as these constitute critical lifelines. The evidence base for exposure, sensitivity, and adaptive capacity to higher sea levels and storm surges is very strong, both from empirical observation and historical experience and from studies projecting future impacts on critical coastal infrastructure. There are numerous publications concerning the effects of sea level rise and storm surges on roadways, coastal bridges, and supply of refined products.c9647af9-db7f-4f6a-89bd-2f2293ad26e5,ca601d1d-e05f-4c7c-b5ab-7f35cd27ad57,15fe2aef-6d15-4ea6-a62c-ebb2563d8b4e,8ce65ffc-cdb9-4022-98de-de8bbb141837,6fd7abfe-17d7-49a9-bc90-bf85fa4041d3,ab12aa5f-f335-4633-844f-e0af50715832,78fbf40c-2639-480a-8410-5be748750f2b The information on roadways came from various reports (for example, DOT 2012; Transportation Research Board 20116b4d3283-49dc-4b8d-830b-aa554e37279f,721cfdbb-b8e5-424e-b09d-8ce0b059a431) and other publications (for example, State of Louisiana 2012f1d65fb3-933a-4bbf-b6ac-25ea4d0409d5). The impact on coastal bridges is documented in U.S. Department of Transportation reports.6b4d3283-49dc-4b8d-830b-aa554e37279f,a6c54272-7833-4387-a562-229e9e98b233 A number of publications explored the impacts on supply of refined oil-based products such as gasoline.e9bc4af5-c2c2-409a-93d2-b2b6dcdb6528,250d03a2-c6b7-45fb-9585-4e9385aefe2f,85805796-ffa7-4396-bdf4-10a0a3cab671,996f4616-6ae6-4248-9351-f28215ac556c,c6da3c06-f7f4-4842-93b0-23f5beb8d67f The evidence base is moderate for the interaction of inland and coastal flooding. There are many and recent publications concerning impacts to wastewater treatment plants3836ed81-4502-4b89-9b27-9fe9ee2d6c42,388a539b-7eb8-48a5-be34-6568a5af8682,5a9e11bc-fdae-474b-a2ad-fe51fa2bb95a and drainage systems.18d757e5-9494-4ca8-9dfe-5cc335c8ffb7,5138b20c-7049-433e-a1ec-24417cccd3c2,8ce65ffc-cdb9-4022-98de-de8bbb141837,a5fd7659-3d17-445f-a924-44a659bb11d1,f03c8590-8b20-442a-a603-dee6c3bf70e1,73596de6-c45e-4dea-b441-fa967b6f658e,a13ad871-f5b6-430f-b2d3-cfc1b161e418 These impacts lead to increased risk of urban flooding and disruption of essential services to urban residents.' href: http://52.38.26.42:8080/report/nca3/chapter/coastal-zone/finding/coastal-lifelines-vulnerable.yaml identifier: coastal-lifelines-vulnerable ordinal: 1 process: 'A central component of the assessment process was a Chapter Lead Authors meeting held in St. Louis, Missouri in April 2012. The key messages were initially developed at this meeting. Key vulnerabilities were operationally defined as those challenges that can fundamentally undermine the functioning of human and natural coastal systems. They arise when these systems are highly exposed and sensitive to climate change and (given present or potential future adaptive capacities) insufficiently prepared or able to respond. The vulnerabilities that the team decided to focus on were informed by ongoing interactions of the author team with coastal managers, planners, and stakeholders, as well as a review of the existing literature. In addition, the author team conducted a thorough review of the technical input reports (TIR) and associated literature, including the coastal zone foundational TIR prepared for the National Climate Assessment (NCA).c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Chapter development was supported by numerous chapter author technical discussions via teleconference from April to June 2012.' report_identifier: nca3 statement: 'Coastal lifelines, such as water supply and energy infrastructure and evacuation routes, are increasingly vulnerable to higher sea levels and storm surges, inland flooding, erosion, and other climate-related changes.' uncertainties: 'The projected rate of sea level rise (SLR) is fully accounted for through the use of common scenarios. We note, however, that there is currently limited impacts literature yet that uses the lowest or highest 2100 scenario and none that specifically use the broader range of SLR (0.2 to 2 meters, or 0.7 to 6.6 feet, by 2100) d8089822-678e-4834-a1ec-0dca1da35314 and NCA land-use scenarios (60% to 164% increase in urban and suburban land area).05a757a8-7972-4f33-aed8-424b0afb8fc4 The severity and frequency of storm damage in any given location cannot yet be fully accounted for due to uncertainties in projecting future extratropical and tropical storm frequency, intensity, and changes in storm tracks for different regions (Ch. 2: Our Changing Climate).c9647af9-db7f-4f6a-89bd-2f2293ad26e5 The timely implementation and efficacy of adaptation measures, including planned retreat, in mitigating damages is accounted for in the underlying literature (for example, by varying assumptions about the timing of implementation of adaptation measures and the type of adaptation measures) such as hard protection, elevation, relocation, or protection through wetlands and dunes in front of the infrastructure in question) (for example, Aerts and Botzen 2012; Biging et al. 2012; Bloetscher et al. 2011; Heberger et al. 2009; Irish et al. 2010; Kirshen et al. 201118d757e5-9494-4ca8-9dfe-5cc335c8ffb7,ca601d1d-e05f-4c7c-b5ab-7f35cd27ad57,fc366ced-fcf5-41de-9bd3-cc09c1d33ab6,0fece8dd-1233-4ec3-8958-2944a5b3c967,e378c785-05f0-4f3f-97b1-889eb7e5036d,3836ed81-4502-4b89-9b27-9fe9ee2d6c42). However, such studies can only test the sensitivity of conclusions to these assumptions; they do not allow statements about what is occurring on the ground. Additional uncertainties arise from the confluence of climate change impacts from the inland and ocean side, which have yet to be studied in an integrated fashion across different coastal regions of the United States.' uri: /report/nca3/chapter/coastal-zone/finding/coastal-lifelines-vulnerable url: ~ - chapter_identifier: coastal-zone confidence: 'Given the evidence base, the well-established accumulation of economic assets and activities in coastal areas, and the directional trend of sea level rise, we have very high confidence in the main conclusion that resources and assets that are nationally important to economic productivity are threatened by SLR and climate change. While there is currently no indication that the highest-value assets and economic activities are being abandoned in the face of sea level rise and storm impacts, we have very high confidence that the cost of protecting these assets in place will be high, and that the cost will be higher the faster sea level rises relative to land. We have very high confidence that adequate planning and arrangement for future financing mechanisms, timely implementation of hazard mitigation measures, and effective disaster response will keep the economic impacts and adaptation costs lower than if these actions are not taken. We are not able to assess timing or total cost of protecting or relocating economic assets with any confidence at this time, due to uncertainties in asset-specific elevation above sea level, in the presence and efficacy of protective measures (at present and in the future), in the feasibility of relocation in any particular case, and uncertainties in future storm surge heights and storm frequencies.' evidence: 'The key message and supporting text summarize extensive evidence documented in the coastal zone technical input report.c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Technical input reports (68) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input, as well as the extant scientific literature. The evidence base for increased exposure to assets is strong. Many publications have assessed at-risk areas (for example, Biging et al. 2012; Cooley et al. 2012; Heberger et al. 2009; Neumann et al. 2010aca601d1d-e05f-4c7c-b5ab-7f35cd27ad57,0fece8dd-1233-4ec3-8958-2944a5b3c967,2ef35c42-765f-407e-b517-11db86a11c70,c7d9400d-b597-4a6f-bd6e-6ad907669146). Highly reliable economic activity information is available from recurring surveys conducted by the National Oceanographic and Atmospheric Administration (NOAA) and others, and asset exposure is conclusively demonstrated by historical information (from storm and erosion damage), elevation data (in Geographic Information System (GIS)-based, LIDAR, and other forms), and numerous vulnerability and adaptation studies of the built environment. Further evidence is provided in technical input reports and other NCA chapters on infrastructure and urban systems (Ch. 11: Urban),f0803451-5a89-474a-974f-99c13fdc725d transportation (Ch. 5: Transportation),6b4d3283-49dc-4b8d-830b-aa554e37279f and energy (Ch. 4: Energy). A number of studies in addition to the ones cited in the text, using various economic assumptions, aim to assess the cost of protecting or relocating coastal assets and services. Many publications and reports explore the cost of replacing services offered by ports,6b4d3283-49dc-4b8d-830b-aa554e37279f,6ef87983-391a-497e-88d7-0e9ad38c215d though one study3f1fc729-ccd6-48f0-9062-5bc999cc068e notes that few ports are implementing adaptation practices to date. The economic consequences of climate change on tourism are supported by a number of recent studies.88c9a12d-64ab-4f45-ad5c-58196f9e824f,da18c6c7-f8e5-4783-8d85-678cbc3ed429,109eb10a-7b33-4fb9-93d6-6d483fc330b7,6ef87983-391a-497e-88d7-0e9ad38c215d,6fd7abfe-17d7-49a9-bc90-bf85fa4041d3 The threats of climate change on fishing have been explored in the coastal zone technical input report.c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Additional evidence comes from empirical observation: public statements by private sector representatives and public officials indicate high awareness of economic asset exposure and a determination to see those assets protected against an encroaching sea, even at high cost (New York City, Miami Dade County, San Francisco airport, etc.). The economic value of exposed assets and activities is frequently invoked when they get damaged or interrupted during storm events (for example, Hallegattee 2012b8396a7f-859b-47be-adcb-16af1eae2dde). Threats to economic activity are also consistently cited as important to local decision-making in the coastal context (for example, Titus et al. 2009ca5b5626-5013-41d6-8815-913abda50bf7).' href: http://52.38.26.42:8080/report/nca3/chapter/coastal-zone/finding/important-assets-increasingly-exposed.yaml identifier: important-assets-increasingly-exposed ordinal: 2 process: 'A central component of the assessment process was a Chapter Lead Authors meeting held in St. Louis, Missouri in April 2012. The key messages were initially developed at this meeting. Key vulnerabilities were operationally defined as those challenges that can fundamentally undermine the functioning of human and natural coastal systems. They arise when these systems are highly exposed and sensitive to climate change and (given present or potential future adaptive capacities) insufficiently prepared or able to respond. The vulnerabilities that the team decided to focus on were informed by ongoing interactions of the author team with coastal managers, planners, and stakeholders, as well as a review of the existing literature. In addition, the author team conducted a thorough review of the technical input reports (TIR) and associated literature, including the coastal zone foundational TIR prepared for the National Climate Assessment (NCA).c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Chapter development was supported by numerous chapter author technical discussions via teleconference from April to June 2012.' report_identifier: nca3 statement: 'Nationally important assets, such as ports, tourism and fishing sites, in already-vulnerable coastal locations, are increasingly exposed to sea level rise and related hazards. This threatens to disrupt economic activity within coastal areas and the regions they serve and results in significant costs from protecting or moving these assets.' uncertainties: 'The projected rate of sea level rise is fully accounted for through the use of common scenarios. We note, however, that there is currently limited impacts literature that uses the lowest or highest scenario for 2100, and no studies that specifically use the broader range of SLR (0.7 to 6.6 feet,) and NCA land-use scenarios (60% to 164% increase in urban and suburban land area).05a757a8-7972-4f33-aed8-424b0afb8fc4 The projected severity and frequency of storm damage in any given location cannot yet be fully accounted for due to uncertainties in projecting future extratropical and tropical storm frequency, intensity, and changes in storm tracks for different regions.c9647af9-db7f-4f6a-89bd-2f2293ad26e5 The timely implementation and efficacy of adaptation measures, including planned retreat, in mitigating damages are accounted for in the underlying literature (for example, by varying assumptions about the timing of implementation of adaptation measures, the type of adaptation measures, and other economic assumptions such as discount rates). However, such studies can only test the sensitivity of conclusions to these assumptions; they do not allow statements about what is occurring on the ground. Well-established post-hoc assessments96dc08d0-5be0-4d8d-b839-acac057dfd5b suggest that hazard mitigation action is highly cost-effective (for every dollar spent, four dollars in damages are avoided). A more recent study suggests an even greater cost-effectiveness.2ef35c42-765f-407e-b517-11db86a11c70' uri: /report/nca3/chapter/coastal-zone/finding/important-assets-increasingly-exposed url: ~ - chapter_identifier: coastal-zone confidence: 'We have high confidence in this conclusion, as it is based on well-accepted techniques, replicated in several place-based case studies, and on a nationwide analysis, using reliable Census data. Consistency in insights and conclusions in these studies, and in others across regions, sectors, and nations, add to the confidence. The conclusion does involve significant projection uncertainties, however, concerning where socially vulnerable populations will be located several decades from now. Sensitivity analysis of this factor, and overall a wider research base is needed, before a higher confidence assessment can be assigned.' evidence: 'The key message and supporting text summarize extensive evidence documented in the coastal zone technical input report.c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Technical input reports (68) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input, along with the extant literature. Evidence base is moderate: assessment of the social vulnerability to coastal impacts of climate change is a comparatively new research focus in the United States, and clearly an advance since the prior NCA.e251f590-177e-4ba6-8ed1-6f68b5e54c8a There are currently multiple published, peer-reviewed studies, by different author teams, using different vulnerability metrics, which all reach the same conclusion: economically and socially vulnerable individuals and communities face significant coastal risks and have a lower adaptive capacity than less socially vulnerable populations. Studies have shown that the U.S. coastal population is growing c5b5b0ad-2a2e-45da-868f-54313282590a,85f2d3eb-131c-4622-8d3f-fd6c1abe2f9c and have assessed the importance of this population for climate change exposure.97387e44-8bfc-413a-948c-e6dc67f5e7cd,ea43448c-4127-4757-8447-b71e95f65fce,ed5a3cbf-175f-47f5-91f8-2d6225e18b3e The social factors that play key roles in coastal vulnerability are detailed in numerous publications.c7d9400d-b597-4a6f-bd6e-6ad907669146,7e30a623-2378-40b0-8295-729d582193ec,796c4617-7dcd-433e-bb0e-805cdab4c136,2f7da448-3778-4a00-ada5-e71c63dee873,808ba10c-7b2e-4d68-910f-0a00c168c503,a02c9e99-df7c-4f4b-8345-74c470d39b16 There is an additional body of evidence emerging in the literature that also supports this key message, namely the growing literature on “barriers to adaptation,” particularly from studies conducted here in the United States.c9647af9-db7f-4f6a-89bd-2f2293ad26e5,c7d9400d-b597-4a6f-bd6e-6ad907669146,822df4d2-3a7d-450b-9924-5543158d5d08,8472db31-6ff4-47f2-8842-4173dcd58e4e,e631bb4f-7e97-4596-9ad5-8b6cacf4f29b,c1e86158-f0cf-4b7d-bc99-02fe2630e8af This literature reports on the limitations poorer communities face at present in beginning adaptation planning, and on the challenges virtually all communities face in prioritizing adaptation and moving from planning to implementation of adaptation options. There is empirical evidence for how difficult it is for small, less wealthy communities (for example, the Native communities in Alaska or southern Louisiana) to obtain federal funds to relocate from eroding shorelines.70dfc033-956a-400a-bc71-86379a7b7350,42269c56-1785-48ec-a81b-6eeb784de417 Eligibility criteria (positive benefit-cost ratios) make it particularly difficult for low-income communities to obtain such funds; current federal budget constraints limit the available resources to support managed retreat and relocation.3268bd48-c8c0-4c28-afdb-281d35319c1d,ea960d1b-926b-4751-8608-4c8d62ec5522 The recent economic hardship has placed constraints even on the richer coastal communities in the U.S. in developing and implementing adaptation strategies, for example in California.e631bb4f-7e97-4596-9ad5-8b6cacf4f29b While the economic situation, funding priorities, or institutional mechanisms to provide support to socially vulnerable communities will not remain static over time, there is no reliable scientific evidence for how these factors may change in the future.' href: http://52.38.26.42:8080/report/nca3/chapter/coastal-zone/finding/coastal-socioeconomic-disparities.yaml identifier: coastal-socioeconomic-disparities ordinal: 3 process: 'A central component of the assessment process was a Chapter Lead Authors meeting held in St. Louis, Missouri in April 2012. The key messages were initially developed at this meeting. Key vulnerabilities were operationally defined as those challenges that can fundamentally undermine the functioning of human and natural coastal systems. They arise when these systems are highly exposed and sensitive to climate change and (given present or potential future adaptive capacities) insufficiently prepared or able to respond. The vulnerabilities that the team decided to focus on were informed by ongoing interactions of the author team with coastal managers, planners, and stakeholders, as well as a review of the existing literature. In addition, the author team conducted a thorough review of the technical input reports (TIR) and associated literature, including the coastal zone foundational TIR prepared for the National Climate Assessment (NCA).c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Chapter development was supported by numerous chapter author technical discussions via teleconference from April to June 2012.' report_identifier: nca3 statement: 'Socioeconomic disparities create uneven exposures and sensitivities to growing coastal risks and limit adaptation options for some coastal communities, resulting in the displacement of the most vulnerable people from coastal areas.' uncertainties: 'The body of research on this topic is largely new since the prior NCA in 2009.e251f590-177e-4ba6-8ed1-6f68b5e54c8a Each of the peer-reviewed studies discusses data gaps and methodological limitations, as well as the particular challenge of projecting demographic variables – a notoriously difficult undertaking – forward in time. While methods for population projections are well established (typically using housing projections), those, in turn, depend on more difficult to make assumptions about fertility, migration, household size, and travel times to urban areas. The conclusion is limited by uneven coverage of in-depth vulnerability studies; although those that do exist are consistent with and confirm the conclusions of a national study.8b9be5aa-a391-4ed6-a26e-20959b4417ac This latter study was extended by applying the same approach, data sources, and methodology to regions previously not covered, thus closing important informational gaps (Hawai‘i, Alaska, the Great Lakes region). Data gaps remain for most coastal locations in the Pacific Islands, Puerto Rico, and other U.S. territories. The most important limit on understanding is the current inability to project social vulnerability forward in time. While some social variables are more easily predicted (for example, age and gender distribution) than others (for example, income distribution, ethnic composition, and linguistic abilities), the predictive capability declines the further out projections aim (beyond 2030 or 2050). Further, it is particularly difficult to project these variables in specific places subject to coastal risks, as populations are mobile over time, and no existing model reliably predicts place-based demographics at the scale important to these analyses.' uri: /report/nca3/chapter/coastal-zone/finding/coastal-socioeconomic-disparities url: ~ - chapter_identifier: coastal-zone confidence: 'We have very high confidence that coastal ecosystems are particularly vulnerable to climate change because they have already been dramatically altered by human stresses, as documented in extensive and conclusive evidence. We have very high confidence that climate change will result in further reduction or loss of the services that these ecosystems provide, as there is extensive and conclusive evidence related to this vulnerability. We have high confidence that climatic change will include “potentially irreversible impacts.” Site-specific evidence of potentially irreversible impacts exists in the literature. This vulnerability is frequently identified by studies of coastal ecosystems. However, methods, research, and models are still being developed for understanding, documenting, and predicting potentially irreversible impacts across all types of coastal ecosystems' evidence: 'The key message and supporting text summarize extensive evidence documented in the coastal zone technical input report.c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Technical input reports (68) on a wide range of topics were also received and reviewed as part of the Federal Register Notice solicitation for public input, along with the extant literature. Evidence base is strong for this part of the key message: “Coastal ecosystems are particularly vulnerable to climate change because many have already been dramatically altered by human stresses.” The degradation and depletion of coastal systems due to human stresses (for example, pollution, habitat destruction, and overharvesting) has been widely documented throughout the U.S. and the world.057e69e7-a2a7-48f5-85f5-7214ed7b5bf7,412faea9-5a62-4e2f-95d1-a475b33c39fb,3d9112b9-6aa1-4614-9599-6966c9591ef9,cd8312dc-7405-4bf0-ae48-c5af32814d65,8712f79b-218f-4f08-b4a9-2401d8aa1b14,d9ec3739-08f5-4e71-ada0-194fd3b35d63,d3e0a9e1-9ff9-492c-ba13-9f24976fa65a The degree of degradation varies based on location and level of human impact. However, evidence of degradation is available for all types of U.S. coastal ecosystems, from coral reefs to seagrasses and rocky shores. Human stresses can be direct (for example, habitat destruction due to dredging of bays) or indirect (for example, food web disruption due to overfishing). There is also consistent evidence that ecosystems degraded by human activities are less resilient to changes in climatic factors, such as water temperature, precipitation, and sea level rise (for example, Gedan et al. 2009; Glick et al. 2011; Williams and Grosholz 2008f235a577-2e08-47eb-9ee2-3cc5dbbc234b,fdb15eb5-7454-4c42-b331-d9859ea4320e,92da0798-eb2c-44a8-991d-829fdff77dc3). Evidence base is strong: “climate change will result in further reduction or loss of the services that these ecosystems provide.” The impacts of changing coastal conditions (for example, changes associated with altered river inflows, higher temperatures, and the effects of high rates of relative sea level rise) on coastal ecosystems and their associated services have been extensively documented through observational and empirical studies, including recent publications.cfdaea11-95e2-4789-914b-74901b2f26b0,f74345fb-5efc-4b8c-9dcc-44eb3ad7e7a1,24763b7e-38b5-4e8d-b7c2-901431f1d01c,5f01fe1e-d4c6-4974-b238-7dbacf170159,fdb15eb5-7454-4c42-b331-d9859ea4320e,febd979a-7e7b-4ae3-8fdc-d9aa62dea49c Many models of coastal ecosystem responses to climatic factors have been well-validated with field data. Given the existing knowledge of ecosystem responses, future climate projections, and the interactions with non-climatic stressors that further exacerbate climatic impacts, evidence is strong of the potential for further reduction and/or loss of ecosystem services. Evidence is suggestive: “including potentially irreversible impacts.” Severe impacts (for example, mass coral bleaching events and rapid species invasions) have been extensively documented for U.S. coastal ecosystems. Many experts have suggested that some of these impacts may be irreversible91134a9b-6dde-4607-bc9f-6301da1e1800 and never before seen conditions have been documented.9ec1ded2-2422-45f4-b84f-c32eeb34b7ff,291c90fe-6766-40c2-9580-aea56178ecaa,497e2536-1556-4905-a4b1-93fa2175e3b5,7ec245d4-187a-493b-9262-d2e89b5c29c4 Recovery may or may not be possible in different instances; this depends on factors that are not well-understood, such as the adaptive capacity of ecosystems, future projections of change that consider interactions among multiple climatic and non-climatic human alterations of systems, the dynamics and persistence of alternative states that are created after a regime shift has occurred, and whether or not the climatic and/or non-climatic stressors that lead to impacts will be ameliorated.b7708c1a-0eb5-47db-a089-ff40be29c884,032cd8fc-fb93-445b-a94b-a18dda336372,4d7318c7-da72-425c-9506-5eba7d21c0f9,5b779eb3-6b85-4781-93ec-30197cfb259c,697b2dc9-5ef5-44da-bc24-5b1ada3e0b45,021db5fd-4164-47ba-ba6a-f7f1895fbd0a' href: http://52.38.26.42:8080/report/nca3/chapter/coastal-zone/finding/coastal-ecosystems-vulnerable.yaml identifier: coastal-ecosystems-vulnerable ordinal: 4 process: 'A central component of the assessment process was a Chapter Lead Authors meeting held in St. Louis, Missouri in April 2012. The key messages were initially developed at this meeting. Key vulnerabilities were operationally defined as those challenges that can fundamentally undermine the functioning of human and natural coastal systems. They arise when these systems are highly exposed and sensitive to climate change and (given present or potential future adaptive capacities) insufficiently prepared or able to respond. The vulnerabilities that the team decided to focus on were informed by ongoing interactions of the author team with coastal managers, planners, and stakeholders, as well as a review of the existing literature. In addition, the author team conducted a thorough review of the technical input reports (TIR) and associated literature, including the coastal zone foundational TIR prepared for the National Climate Assessment (NCA).c9647af9-db7f-4f6a-89bd-2f2293ad26e5 Chapter development was supported by numerous chapter author technical discussions via teleconference from April to June 2012.' report_identifier: nca3 statement: 'Coastal ecosystems are particularly vulnerable to climate change because many have already been dramatically altered by human stresses; climate change will result in further reduction or loss of the services that these ecosystems provide, including potentially irreversible impacts.' uncertainties: 'Since the 2009 NCA,e251f590-177e-4ba6-8ed1-6f68b5e54c8a new studies have added weight to previously established conclusions. The major advance lies in the examination of tipping points for species and entire ecosystems (for example, Barnosky et al. 2012; Folke et al. 2004; Foti et al. 2013; Hoegh-Guldberg and Bruno 201091134a9b-6dde-4607-bc9f-6301da1e1800,211334ae-d5e0-48cc-9f29-9e24669b4af3,497e2536-1556-4905-a4b1-93fa2175e3b5,4d7318c7-da72-425c-9506-5eba7d21c0f9). Existing uncertainties and future research needs were identified through reviewing the NCA technical inputs and other peer-reviewed, published literature on these topics, as well as through our own identification and assessment of knowledge gaps. Key uncertainties in our understanding of ecosystem impacts of climate change in coastal areas are associated with: • the interactive effects and relative contributions of multiple climatic and non-climatic stressors on coastal organisms and ecosystems; • how the consequences of multiple stressors for individual species combine to affect community- and ecosystem-level interactions and functions; • the projected magnitude of coastal ecosystem change under different scenarios of temperature change, sea level rise, and land-use change, particularly given the potential for feedbacks and non-linearities in ecosystem responses • the potential adaptive capacity of coastal organisms and ecosystems to climate change; • trajectories, timeframes, and magnitudes of coastal ecosystem recovery; • the dynamics and persistence of alternative states that are created after ecosystem regime shifts have occurred; and • the potential and likelihood for irreversible climate-related coastal ecosystem change. In general, relatively little work to date has been conducted to project future coastal ecosystem change under integrative scenarios of temperature change, sea level rise, and changes in human uses of, and impacts to, coastal ecosystems (for example, through land-use change). Advancing understanding and knowledge associated with this key uncertainty, as well as the others included in the above list, would be fostered by additional research. Assessment of confidence based on evidence We have very high confidence that coastal ecosystems are particularly vulnerable to climate change because they have already been dramatically altered by human stresses, as documented in extensive and conclusive evidence. We have very high confidence that climate change will result in further reduction or loss of the services that these ecosystems provide, as there is extensive and conclusive evidence related to this vulnerability. We have high confidence that climatic change will include “potentially irreversible impacts.” Site-specific evidence of potentially irreversible impacts exists in the literature. This vulnerability is frequently identified by studies of coastal ecosystems. However, methods, research, and models are still being developed for understanding, documenting, and predicting potentially irreversible impacts across all types of coastal ecosystems.' uri: /report/nca3/chapter/coastal-zone/finding/coastal-ecosystems-vulnerable url: ~