气候变化领域集成服务门户(CCPortal): An observation-based scaling model for climate sensitivity estimates and global projections to 2100

CCPortal

DOI	10.1007/s00382-020-05521-x
	An observation-based scaling model for climate sensitivity estimates and global projections to 2100
	Hébert R.; Lovejoy S.; Tremblay B.
发表日期	2021
ISSN	0930-7575
卷号	56 期号:2021-03-04
英文摘要	We directly exploit the stochasticity of the internal variability, and the linearity of the forced response to make global temperature projections based on historical data and a Green’s function, or Climate Response Function (CRF). To make the problem tractable, we take advantage of the temporal scaling symmetry to define a scaling CRF characterized by the scaling exponent H, which controls the long-range memory of the climate, i.e. how fast the system tends toward a steady-state, and an inner scale τ≈ 2 years below which the higher-frequency response is smoothed out. An aerosol scaling factor and a non-linear volcanic damping exponent were introduced to account for the large uncertainty in these forcings. We estimate the model and forcing parameters by Bayesian inference which allows us to analytically calculate the transient climate response and the equilibrium climate sensitivity as: 1.7-0.2+0.3 K and 2.4-0.6+1.3 K respectively (likely range). Projections to 2100 according to the RCP 2.6, 4.5 and 8.5 scenarios yield warmings with respect to 1880–1910 of: 1.5-0.2+0.4K, 2.3-0.5+0.7 K and 4.2-0.9+1.3 K. These projection estimates are lower than the ones based on a Coupled Model Intercomparison Project phase 5 multi-model ensemble; more importantly, their uncertainties are smaller and only depend on historical temperature and forcing series. The key uncertainty is due to aerosol forcings; we find a modern (2005) forcing value of [-1.0,-0.3]Wm-2 (90 % confidence interval) with median at -0.7Wm-2. Projecting to 2100, we find that to keep the warming below 1.5 K, future emissions must undergo cuts similar to RCP 2.6 for which the probability to remain under 1.5 K is 48 %. RCP 4.5 and RCP 8.5-like futures overshoot with very high probability. © 2020, The Author(s).
英文关键词	Climate sensitivity; Global mean temperature; Global warming; Projections; RCP scenarios; Scaling
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183395
作者单位	Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Telegrafenberg A45, Potsdam, 14473, Germany; Department of Physics, McGill University, 3600 rue University, Montréal, QC H3A 2T8, Canada; Department of Atmospheric and Oceanic Sciences, McGill University, 845 rue Sherbrooke Ouest, Montréal, QC H3A 0G4, Canada
推荐引用方式 GB/T 7714	Hébert R.,Lovejoy S.,Tremblay B.. An observation-based scaling model for climate sensitivity estimates and global projections to 2100[J],2021,56(2021-03-04).
APA	Hébert R.,Lovejoy S.,&Tremblay B..(2021).An observation-based scaling model for climate sensitivity estimates and global projections to 2100.Climate Dynamics,56(2021-03-04).
MLA	Hébert R.,et al."An observation-based scaling model for climate sensitivity estimates and global projections to 2100".Climate Dynamics 56.2021-03-04(2021).