--- - attrs: .reference_type: 0 Abstract: 'Observations show snowpack has declined across much of the western United States over the period 1950–99. This reduction has important social and economic implications, as water retained in the snowpack from winter storms forms an important part of the hydrological cycle and water supply in the region. A formal model-based detection and attribution (D–A) study of these reductions is performed. The detection variable is the ratio of 1 April snow water equivalent (SWE) to water-year-to-date precipitation (P), chosen to reduce the effect of P variability on the results. Estimates of natural internal climate variability are obtained from 1600 years of two control simulations performed with fully coupled ocean–atmosphere climate models. Estimates of the SWE/P response to anthropogenic greenhouse gases, ozone, and some aerosols are taken from multiple-member ensembles of perturbation experiments run with two models. The D–A shows the observations and anthropogenically forced models have greater SWE/P reductions than can be explained by natural internal climate variability alone. Model-estimated effects of changes in solar and volcanic forcing likewise do not explain the SWE/P reductions. The mean model estimate is that about half of the SWE/P reductions observed in the west from 1950 to 1999 are the result of climate changes forced by anthropogenic greenhouse gases, ozone, and aerosols.' Author: "Pierce, D.W.\rBarnett, T.P.\rHidalgo, H.G.\rDas, T.\rBonfils, C.\rSanter, B.D.\rBala, G.\rDettinger, M.D.\rCayan, D.R.\rMirin, A.\rWood, A. W. \rNozawa, T." DOI: 10.1175/2008JCLI2405.1 ISSN: 1520-0442 Issue: 23 Journal: Journal of Climate Keywords: 'Snowpack, ; Hydrologic cycle, ; Trends, ; Coupled models, ; Greenhouse gases' Pages: 6425-6444 Title: Attribution of declining western US snowpack to human effects URL: http://journals.ametsoc.org/doi/abs/10.1175/2008JCLI2405.1 Volume: 21 Year: 2008 _chapter: '["Ch. 20: Southwest FINAL","Ch. 28: Adaptation FINAL","Ch. 3: Water Resources FINAL","Appendix 3: Climate Science FINAL","Ch. 21: Northwest FINAL"]' _record_number: 2495 _uuid: 0d8b090e-e060-4f9d-a442-b7e050608a20 reftype: Journal Article child_publication: /article/10.1175/2008JCLI2405.1 href: http://52.38.26.42:8080/reference/0d8b090e-e060-4f9d-a442-b7e050608a20.yaml identifier: 0d8b090e-e060-4f9d-a442-b7e050608a20 uri: /reference/0d8b090e-e060-4f9d-a442-b7e050608a20 - attrs: .reference_type: 9 Editor: "Garfin, G.\rJardine, A.\rMerideth, R.\rBlack, Mary\rOverpeck, J. " Publisher: Southwest Climate Alliance Title: 'Assessment of Climate Change in the Southwest United States: a Technical Report Prepared for the U.S. National Climate Assessment. A report by the Southwest Climate Alliance' Year: 2012 _chapter: '["Ch. 20: Southwest FINAL"]' _record_number: 4075 _uuid: 17ad4429-1321-4e7c-9cd5-3554eb0c3b38 reftype: Edited Book child_publication: /report/swccar-assessment-climate-change-in-southwest-us href: http://52.38.26.42:8080/reference/17ad4429-1321-4e7c-9cd5-3554eb0c3b38.yaml identifier: 17ad4429-1321-4e7c-9cd5-3554eb0c3b38 uri: /reference/17ad4429-1321-4e7c-9cd5-3554eb0c3b38 - attrs: .reference_type: 7 Accession Number: 173 Author: "Schneider, S.H.\rS. Semenov\rA. Patwardhan\rI. Burton\rC.H.D. Magadza\rM. Oppenheimer\rA.B. Pittock\rA. Rahman\rJ.B. Smith\rA. Suarez\rF. Yamin" Book Title: 'Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change' Editor: "Parry, M.L.\rCanziani, O.F.\rPalutikof, J.P.\rvan der Linden, P.J.\rHanson, C.E." Pages: 779-810 Place Published: 'Cambridge, UK and New York, NY' Publisher: Cambridge University Press Reviewer: 3277e83c-e374-4ed5-b0a2-0adadfaf118d Title: 'Ch. 19: Assessing key vulnerabilities and the risk from climate change' Year: 2007 _chapter: '["Ch. 20: Southwest FINAL"]' _record_number: 4020 _uuid: 3277e83c-e374-4ed5-b0a2-0adadfaf118d reftype: Book Section child_publication: /report/ipcc-ar4-wg2 href: http://52.38.26.42:8080/reference/3277e83c-e374-4ed5-b0a2-0adadfaf118d.yaml identifier: 3277e83c-e374-4ed5-b0a2-0adadfaf118d uri: /reference/3277e83c-e374-4ed5-b0a2-0adadfaf118d - attrs: .reference_type: 0 Abstract: 'This article applies formal detection and attribution techniques to investigate the nature of observed shifts in the timing of streamflow in the western United States. Previous studies have shown that the snow hydrology of the western United States has changed in the second half of the twentieth century. Such changes manifest themselves in the form of more rain and less snow, in reductions in the snow water contents, and in earlier snowmelt and associated advances in streamflow “center” timing (the day in the “water-year” on average when half the water-year flow at a point has passed). However, with one exception over a more limited domain, no other study has attempted to formally attribute these changes to anthropogenic increases of greenhouse gases in the atmosphere. Using the observations together with a set of global climate model simulations and a hydrologic model (applied to three major hydrological regions of the western United States—the California region, the upper Colorado River basin, and the Columbia River basin), it is found that the observed trends toward earlier “center” timing of snowmelt-driven streamflows in the western United States since 1950 are detectably different from natural variability (significant at the p < 0.05 level). Furthermore, the nonnatural parts of these changes can be attributed confidently to climate changes induced by anthropogenic greenhouse gases, aerosols, ozone, and land use. The signal from the Columbia dominates the analysis, and it is the only basin that showed a detectable signal when the analysis was performed on individual basins. It should be noted that although climate change is an important signal, other climatic processes have also contributed to the hydrologic variability of large basins in the western United States.' Author: "Hidalgo, H.G.\rDas, T.\rDettinger, M.D.\rCayan, D.R.\rPierce, D.W.\rBarnett, T.P.\rBala, G.\rMirin, A.\rWood, A.W.\rBonfils, C.\rSanter, B.D.\rNozawa, T." DOI: 10.1175/2009jcli2470.1 ISSN: 1520-0442 Issue: 13 Journal: Journal of Climate Keywords: 'Climate change, Streamflow' Pages: 3838-3855 Title: Detection and attribution of streamflow timing changes to climate change in the western United States URL: http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2470.1 Volume: 22 Year: 2009 _chapter: '["Ch. 20: Southwest FINAL","Ch. 28: Adaptation FINAL","Ch. 3: Water Resources FINAL","Appendix 3: Climate Science FINAL","Ch. 21: Northwest FINAL"]' _record_number: 506 _uuid: 40292b53-9f3a-42f4-9d48-5e614f3d7785 reftype: Journal Article child_publication: /article/10.1175/2009jcli2470.1 href: http://52.38.26.42:8080/reference/40292b53-9f3a-42f4-9d48-5e614f3d7785.yaml identifier: 40292b53-9f3a-42f4-9d48-5e614f3d7785 uri: /reference/40292b53-9f3a-42f4-9d48-5e614f3d7785 - attrs: .reference_type: 7 Author: "Ingram, H.\rD. Feldman\rN. Mantua\rK.L. Jacobs\rD. Fort\rN. Beller-Simms\rA. M. Waple" Book Title: 'Decision-Support Experiments and Evaluations Using Seasonal-to-Interannual Forecasts and Observational Data: A Focus on Water Resources. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research' Editor: "Beller-Simms, N.\rIngram, H.\rFeldman, D.\rMantua, N.\rJacobs, K.L.\rWaple, A.M." Pages: 7-28 Place Published: 'Washington, D.C.' Publisher: U.S. Climate Change Science Program Reviewer: 5030722b-8c1f-43f1-a4e3-5ee701be0a77 Title: 'Ch. 1: The changing context' Year: 2008 _chapter: '["Ch. 20: Southwest FINAL"]' _record_number: 4076 _uuid: 5030722b-8c1f-43f1-a4e3-5ee701be0a77 reftype: Book Section child_publication: /report/ccsp-sap-5_3-2008 href: http://52.38.26.42:8080/reference/5030722b-8c1f-43f1-a4e3-5ee701be0a77.yaml identifier: 5030722b-8c1f-43f1-a4e3-5ee701be0a77 uri: /reference/5030722b-8c1f-43f1-a4e3-5ee701be0a77 - attrs: .reference_type: 7 Author: "Cayan, D\rKunkel, K.\rCastro, C.\rGershunov, A.\rBarsugli, J.\rRay, A.\rOverpeck, J.\rAnderson, M.\rRussell, J.\rRajagopalan, B.\rRangwala, I.\rDuffy, P" Book Title: 'Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment' Editor: "Garfin, G.\rJardine, A.\rMerideth, R.\rBlack, Mary\rLeRoy, Sarah" ISBN: 9781610914468 Pages: 153-196 Place Published: 'Washington, D.C.' Publisher: Island Press Reviewer: 59cf5a07-b64b-418c-acc6-73b7ff4d7d7e Title: 'Ch. 6: Future climate: Projected average' URL: http://swccar.org/sites/all/themes/files/SW-NCA-color-FINALweb.pdf Year: 2013 _chapter: '["Ch. 20: Southwest FINAL","Ch. 3: Water Resources FINAL"]' _record_number: 199 _uuid: 59cf5a07-b64b-418c-acc6-73b7ff4d7d7e reftype: Book Section child_publication: /book/c9625c65-c20f-4163-87fe-cebf734f7836 href: http://52.38.26.42:8080/reference/59cf5a07-b64b-418c-acc6-73b7ff4d7d7e.yaml identifier: 59cf5a07-b64b-418c-acc6-73b7ff4d7d7e uri: /reference/59cf5a07-b64b-418c-acc6-73b7ff4d7d7e - attrs: .reference_type: 0 Author: "Cayan, D.R.\rLuers, A.L.\rFranco, G.\rHanemann, M.\rCroes, B.\rVine, E." DOI: 10.1007/s10584-007-9352-2 ISSN: 0165-0009 Issue: 1 Supplement Journal: Climatic Change Pages: 1-6 Title: Overview of the California climate change scenarios project Volume: 87 Year: 2008 _chapter: '["Ch. 20: Southwest FINAL"]' _record_number: 1240 _uuid: 5d7f76e8-7585-4fb9-89b0-98ef6eac31ee reftype: Journal Article child_publication: /article/10.1007/s10584-007-9352-2 href: http://52.38.26.42:8080/reference/5d7f76e8-7585-4fb9-89b0-98ef6eac31ee.yaml identifier: 5d7f76e8-7585-4fb9-89b0-98ef6eac31ee uri: /reference/5d7f76e8-7585-4fb9-89b0-98ef6eac31ee - attrs: .reference_type: 10 Access Date: 'July 2, 2012' Author: 'Reclamation,' Institution: 'U.S. Department of the Interior, U.S. Bureau of Reclamation' Pages: 226 Place Published: 'Denver, CO' Series Editor: "Alexander, Patty\rBrekke, Levi\rDavis, Gary\rGangopadhyay, Subhrendu\rGrantz, Katrina\rHennig, Charles\rJerla, Carly\rLlewellyn, Dagmar\rMiller, Paul\rPruitt, Tom\r Raff, David\rScott, Tom\rTansey, Michael\rTurner, Toni" Title: 'Reclamation Managing Water in the West. SECURE Water Act Section 9503(c) - Reclamation Climate Change and Water 2011' URL: http://www.usbr.gov/climate/SECURE/docs/SECUREWaterReport.pdf Year: 2011 _chapter: '["Ch. 20: Southwest FINAL","Ch. 11: Urban Systems FINAL","Ch. 28: Adaptation FINAL","Ch. 3: Water Resources FINAL","Ch. 21: Northwest FINAL"]' _record_number: 1389 _uuid: 67b69161-5101-418a-a6c9-1b6a80773305 reftype: Report child_publication: /report/usbr-secure-2011 href: http://52.38.26.42:8080/reference/67b69161-5101-418a-a6c9-1b6a80773305.yaml identifier: 67b69161-5101-418a-a6c9-1b6a80773305 uri: /reference/67b69161-5101-418a-a6c9-1b6a80773305 - attrs: .reference_type: 0 Abstract: 'Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century. We present a regional, multivariable climate change detection and attribution study, using a high- resolution hydrologic model forced by global climate models, focusing on the changes that have already affected this primarily arid region with a large and growing population. The results show that up to 60% of the climate- related trends of river flow, winter air temperature, and snow pack between 1950 and 1999 are human- induced. These results are robust to perturbation of study variates and methods. They portend, in conjunction with previous work, a coming crisis in water supply for the western United States.' Accession Number: 34 Alternate Journal: Science Author: "Barnett, T.P.\rPierce, D.W.\rHidalgo, H.G.\rBonfils, C.\rSanter, B.D.\rDas, T.\rBala, G.\rWood, A.W.\rNozawa, T.\rMirin, A. A.\rCayan, D.R.\rDettinger, M.D." Author Address: '[Barnett, Tim P.; Pierce, David W.; Hidalgo, Hugo G.; Das, Tapash; Cayan, Daniel R.; Dettinger, Michael D.] Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. [Bonfils, Celine; Santer, Benjamin D.; Bala, Govindasamy; Mirin, Arthur A.] Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. [Wood, Andrew W.] Univ Washington, Land Surface Hydrol Res Grp, Seattle, WA 98195 USA. [Nozawa, Toru] Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan. [Cayan, Daniel R.; Dettinger, Michael D.] US Geol Survey, La Jolla, CA 92093 USA.; Barnett, TP, Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA.; tbarnett-ul@ucsd.edu' DOI: 10.1126/science.1152538 Date: Feb ISSN: 0036-8075 Issue: 5866 Journal: Science Keywords: north-america; climate-change; trends; model; attribution; streamflow; snowpack; cycle Language: English Notes: 'ISI Document Delivery No.: 264SW; Times Cited: 69; Cited Reference Count: 29; Barnett, Tim P. Pierce, David W. Hidalgo, Hugo G. Bonfils, Celine Santer, Benjamin D. Das, Tapash Bala, Govindasamy Wood, Andrew W. Nozawa, Toru Mirin, Arthur A. Cayan, Daniel R. Dettinger, Michael D.; Amer assoc advancement science; Washington' Pages: 1080-1083 Title: Human-induced changes in the hydrology of the western United States Type of Article: Article URL: http://www.sciencemag.org/cgi/content/abstract/1152538 Volume: 319 Year: 2008 _chapter: '["Ch. 20: Southwest FINAL","Ch. 8: Ecosystems FINAL","Ch. 3: Water Resources FINAL","Appendix 3: Climate Science FINAL"]' _record_number: 862 _uuid: 87875dde-385b-4f57-b0ae-aa21648b2833 reftype: Journal Article child_publication: /article/10.1126/science.1152538 href: http://52.38.26.42:8080/reference/87875dde-385b-4f57-b0ae-aa21648b2833.yaml identifier: 87875dde-385b-4f57-b0ae-aa21648b2833 uri: /reference/87875dde-385b-4f57-b0ae-aa21648b2833 - attrs: .reference_type: 32 Author: "Kunkel, K. E.\rStevens, L. E.\rStevens, S. E.\rSun, L.\rJanssen, E.\rWuebbles, D.\rRedmond, K.T.\rDobson, J.G." Pages: 87 Place Published: 'Washington, D.C.' Publisher: 'National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service' Title: 'Regional Climate Trends and Scenarios for the U.S. National Climate Assessment: Part 5. Climate of the Southwest U.S. NOAA Technical Report NESDIS 142-5' URL: http://www.nesdis.noaa.gov/technical_reports/NOAA_NESDIS_Tech_Report_142-5-Climate_of_the_Southwest_U.S.pdf Year: 2013 _chapter: '["Ch. 20: Southwest FINAL","Ch. 4: Energy Supply and Use FINAL"]' _record_number: 1413 _uuid: 966bf116-8d6d-41f2-96be-4b66d3e729db reftype: Government Document child_publication: /report/noaa-techreport-nesdis-142-5 href: http://52.38.26.42:8080/reference/966bf116-8d6d-41f2-96be-4b66d3e729db.yaml identifier: 966bf116-8d6d-41f2-96be-4b66d3e729db uri: /reference/966bf116-8d6d-41f2-96be-4b66d3e729db - attrs: .reference_type: 0 Author: "Milly, P. C. D. \rJulio Betancourt\rMalin Falkenmark\rRobert M. Hirsch\rZbigniew W. Kundzewicz\rDennis P. Lettenmaier\rRonald J. Stouffer" DOI: 10.1126/science.1151915 ISSN: 0036-8075 Issue: '5863 ' Journal: Science Pages: 573-574 Title: 'Stationarity is dead: Whither water management?' Volume: 319 Year: 2008 _chapter: '["Ch. 20: Southwest FINAL","Ch. 3: Water Resources FINAL"]' _record_number: 2046 _uuid: c52f2539-9c5e-4ead-b8b7-f1884c5d662e reftype: Journal Article child_publication: /article/10.1126/science.1151915 href: http://52.38.26.42:8080/reference/c52f2539-9c5e-4ead-b8b7-f1884c5d662e.yaml identifier: c52f2539-9c5e-4ead-b8b7-f1884c5d662e uri: /reference/c52f2539-9c5e-4ead-b8b7-f1884c5d662e - attrs: .reference_type: 7 Author: "Theobald, D.M.\rTravis, W.R.\rDrummond, M.A.\rGordon, E.S." Book Title: 'Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment' Editor: "Garfin, G.\rJardine, A.\rMerideth, R.\rBlack, Mary\rLeRoy, Sarah" ISBN: 9781610914468 Pages: 37-55 Place Published: 'Washington, D.C.' Publisher: Island Press Reviewer: c9075dbc-f7c8-4d85-b534-e97282562b3e Title: 'Ch. 3: The Changing Southwest' URL: http://swccar.org/sites/all/themes/files/SW-NCA-color-FINALweb.pdf Year: 2013 _chapter: '["Ch. 20: Southwest FINAL","RG 5 Southwest"]' _record_number: 4686 _uuid: c9075dbc-f7c8-4d85-b534-e97282562b3e reftype: Book Section child_publication: /book/c9625c65-c20f-4163-87fe-cebf734f7836 href: http://52.38.26.42:8080/reference/c9075dbc-f7c8-4d85-b534-e97282562b3e.yaml identifier: c9075dbc-f7c8-4d85-b534-e97282562b3e uri: /reference/c9075dbc-f7c8-4d85-b534-e97282562b3e - attrs: .reference_type: 7 Author: 'Udall, B.' Book Title: 'Assessment of Climate Change in the Southwest United States: A Report Prepared for the National Climate Assessment' Editor: "Garfin, G.\rJardine, A.\rMerideth, R.\rBlack, Mary\rLeRoy, Sarah" ISBN: 9781610914468 Pages: 197–217 Place Published: 'Washington, D.C.' Publisher: Island Press Reviewer: e1a270c3-6eb4-4084-8267-b400584555ea Title: 'Ch. 10: Water: Impacts, risks, and adaptation' URL: http://swccar.org/sites/all/themes/files/SW-NCA-color-FINALweb.pdf Year: 2013 _chapter: '["Ch. 20: Southwest FINAL"]' _record_number: 4021 _uuid: e1a270c3-6eb4-4084-8267-b400584555ea reftype: Book Section child_publication: /book/c9625c65-c20f-4163-87fe-cebf734f7836 href: http://52.38.26.42:8080/reference/e1a270c3-6eb4-4084-8267-b400584555ea.yaml identifier: e1a270c3-6eb4-4084-8267-b400584555ea uri: /reference/e1a270c3-6eb4-4084-8267-b400584555ea - attrs: .reference_type: 0 Author: "Cayan, D.R.\rDas, T.\rPierce, D.W.\rBarnett, T.P.\rTyree, M.\rGershunov, A." DOI: 10.1073/pnas.0912391107 ISSN: 0027-8424 Issue: 50 Journal: Proceedings of the National Academy of Sciences Pages: 21271-21276 Title: Future dryness in the southwest US and the hydrology of the early 21st century drought URL: http://www.pnas.org/content/early/2010/12/06/0912391107.full.pdf+html Volume: 107 Year: 2010 _chapter: '["Ch. 20: Southwest FINAL","Ch. 2: Our Changing Climate FINAL","Ch. 28: Adaptation FINAL","Ch. 3: Water Resources FINAL"]' _record_number: 749 _uuid: f11e90fb-b100-4487-8bac-1a076166d623 reftype: Journal Article child_publication: /article/10.1073/pnas.0912391107 href: http://52.38.26.42:8080/reference/f11e90fb-b100-4487-8bac-1a076166d623.yaml identifier: f11e90fb-b100-4487-8bac-1a076166d623 uri: /reference/f11e90fb-b100-4487-8bac-1a076166d623 - attrs: .reference_type: 0 Author: "Liang, X.\rD.P. Lettenmaier\rE.F. Wood\rS.J. Burges" DOI: 10.1029/94JD00483 Issue: D7 Journal: Journal of Geophysical Research Pages: 14415-14428 Title: A simple hydrologically based model of land surface water and energy fluxes for general circulation models URL: http://onlinelibrary.wiley.com/doi/10.1029/94JD00483/pdf Volume: 99 Year: 1994 _chapter: '["Ch. 20: Southwest FINAL","RF 3","Ch. 2: Our Changing Climate FINAL"]' _record_number: 1542 _uuid: f312de7c-ebe1-447f-93c5-c2ddec528464 reftype: Journal Article child_publication: /article/10.1029/94JD00483 href: http://52.38.26.42:8080/reference/f312de7c-ebe1-447f-93c5-c2ddec528464.yaml identifier: f312de7c-ebe1-447f-93c5-c2ddec528464 uri: /reference/f312de7c-ebe1-447f-93c5-c2ddec528464