To: Sdgla who wrote (1439032 ) 2/13/2024 12:31:50 PM From: Wharf Rat 2 RecommendationsRecommended By
Respond to "So, how well do climate models predict the warming that actually has occurred?"RealClimate: Climate model projections compared to observations Since we have been periodically posting updates (e.g. 2009 , 2010 , 2011 , 2012 , 2015 , 2016 etc.) of model output comparisons to observations across a range of variables, we have now set up this page as a permanent placeholder for the most up-to-date comparisons. We include surface temperature projections from 1981, 1988, CMIP3, CMIP5, and CMIP6, and MSU satellite products from CMIP5 and CMIP6, SST and SSU from CMIP6, and we will update this on an annual basis, or as new observational products become available. For each comparison, we note the last update date, and where the comparison was first discussed. Hansen et al (1981) Original discussion (figure originally courtesy of Geert Jan van Oldenborgh, Hansen et al. (1981) ). Observations are the GISTEMP LOTI annual figures and 5 year mean. Last updated: 15 Jan 2024. Hansen et al (1988) Original discussion (2007) , Last discussion (2018) . Scenarios from Hansen et al. (1988) . Observations are the GISTEMP LOTI annual figures. Trends from 1984: GISTEMP: 0.21ºC/dec, Scenarios A, B, C: 0.33, 0.28, 0.15ºC/dec respectively (all 95% CI ~±0.02 or 0.03). Last updated: 16 Jan 2024. CMIP3 (circa 2004) Last discussion (2015) . Model spread is the 95% envelope of global mean surface temperature anomalies from all individual CMIP3 simulations (using the SRES A1B projection post-2000). Observations (GISTEMP) are the standard quasi-global estimates of anomalies with no adjustment for spatial coverage or the use of SST instead of SAT over the open ocean. Last updated: 12 Jan 2024. "Let’s look at trends in surface air temperature, averaged over the United States since 1945. " Why not look at the entire globe? After all, it's not called "US warming".
