---
attrs:
  .reference_type: 0
  Abstract: 'We compare global-scale changes in satellite estimates of the temperature of the lower troposphere (TLT) with model simulations of forced and unforced TLT changes. While previous work has focused on a single period of record, we select analysis timescales ranging from 10 to 32 years, and then compare all possible observed TLT trends on each timescale with corresponding multi-model distributions of forced and unforced trends. We use observed estimates of the signal component of TLT changes and model estimates of climate noise to calculate timescale-dependent signal-to-noise ratios (S/N). These ratios are small (less than 1) on the 10-year timescale, increasing to more than 3.9 for 32-year trends. This large change in S/N is primarily due to a decrease in the amplitude of internally generated variability with increasing trend length. Because of the pronounced effect of interannual noise on decadal trends, a multi-model ensemble of anthropogenically-forced simulations displays many 10-year periods with little warming. A single decade of observational TLT data is therefore inadequate for identifying a slowly evolving anthropogenic warming signal. Our results show that temperature records of at least 17 years in length are required for identifying human effects on global-mean tropospheric temperature. '
  Author: "Santer, B.D.\rMears, C.\rDoutriaux, C.\rCaldwell, P.\rGleckler, P.J.\rWigley, T.M.L\rSolomon, S.\rGillett, N.P.\rIvanova, D.\rKarl, T.R.\rJ. R. Lanzante\rG. A. Meehl\rP. A. Stott\rK. E. Taylor\rP. W. Thorne\rM. F. Wehner\rF. J. Wentz"
  DOI: 10.1029/2011JD016263
  ISSN: 0148-0227
  Issue: D22105
  Journal: Journal of Geophysical Research
  Pages: 1-19
  Title: 'Separating signal and noise in atmospheric temperature changes: The importance of timescale'
  URL: http://xa.yimg.com/kq/groups/18383638/1244615018/name/2011JD016263.pdf
  Volume: 116
  Year: 2011
  _chapter: '["Ch. 2: Our Changing Climate FINAL"]'
  _record_number: 2744
  _uuid: 3ce3977a-7902-4276-9f6c-17dc3f121c17
  reftype: Journal Article
child_publication: /article/10.1029/2011JD016263
description: 'Separating signal and noise in atmospheric temperature changes: The importance of timescale'
display_name: 'Separating signal and noise in atmospheric temperature changes: The importance of timescale'
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uri: /reference/3ce3977a-7902-4276-9f6c-17dc3f121c17