{"id":20317,"date":"2017-04-11T21:55:08","date_gmt":"2017-04-12T02:55:08","guid":{"rendered":"http:\/\/www.realclimate.org\/?page_id=20317"},"modified":"2026-01-27T11:46:36","modified_gmt":"2026-01-27T16:46:36","slug":"climate-model-projections-compared-to-observations","status":"publish","type":"page","link":"https:\/\/www.realclimate.org\/index.php\/climate-model-projections-compared-to-observations\/","title":{"rendered":"Model-Observation Comparisons"},"content":{"rendered":"<div class=\"kcite-section\" kcite-section-id=\"20317\">\n\n<p>Since we have been <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/category\/climate-science\/model-comp\/\" title=\"periodically posting updates\">periodically posting updates<\/a> since 2009 of climate 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<sup>*,<\/sup> and MSU\/AMSU 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.<\/p>\n\n\n\n<p>This is a collation of opportunity. To be included, there needs to be a pre-existing public archive of the processed model output for the historical period and projections, and at least one regularly-updated observational data source. Lots of these archives have been produced, but they are not easily discoverable, if available publically at all. Please let us know of others that could be included as well by  leaving a comment on the latest <a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/category\/open-thread\/\">open thread<\/a>. You can use these figures anywhere (with a citation and link back to RealClimate).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-medium-font-size\"><a href=\"#gmsat\" title=\"Global mean surface air temperature\">Global mean surface air temperature<\/a><\/li>\n\n\n\n<li class=\"has-medium-font-size\"><a href=\"#msu\" title=\"Satellite estimates of tropospheric temperature\">Satellite estimates of tropospheric temperature<\/a><\/li>\n\n\n\n<li class=\"has-medium-font-size\"><a href=\"#sst\" title=\"Sea Surface temperatures\">Sea Surface temperatures<\/a><\/li>\n\n\n\n<li class=\"has-medium-font-size\"><a href=\"#ssu\" title=\"Stratospheric temperatures\">Stratospheric temperatures<\/a><\/li>\n\n\n\n<li class=\"has-medium-font-size\"><a href=\"#si\" title=\"Sea Ice Extent\/Area\">Arctic Sea Ice Extent\/Area<\/a><\/li>\n<\/ul>\n\n\n\n<p><sup>*<\/sup><em>Note that <span id=\"cite_ITEM-20317-0\" name=\"citation\"><a href=\"#ITEM-20317-0\">Hausfather et al. (2020)<\/a><\/span> made a more complete assessment of surface temperature projections from models from 1970 through to CMIP3 (<a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2019\/12\/how-good-have-climate-models-been-at-truly-predicting-the-future\/\">discussed here<\/a>).<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"gmsat\">Global mean surface temperature anomalies<\/h3>\n\n\n\n<p><strong>Hansen et al (1981)<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"646\" height=\"710\" data-src=\"https:\/\/www.realclimate.org\/images\/\/h81_comparison_2025.png\" alt=\"\" class=\"wp-image-26368 lazyload\" data-srcset=\"https:\/\/www.realclimate.org\/images\/h81_comparison_2025.png 646w, https:\/\/www.realclimate.org\/images\/h81_comparison_2025-273x300.png 273w, https:\/\/www.realclimate.org\/images\/h81_comparison_2025-546x600.png 546w, https:\/\/www.realclimate.org\/images\/h81_comparison_2025-136x150.png 136w\" data-sizes=\"(max-width: 646px) 100vw, 646px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 646px; --smush-placeholder-aspect-ratio: 646\/710;\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2012\/04\/evaluating-a-1981-temperature-projection\/\">Original discussion<\/a> (figure originally courtesy of Geert Jan van Oldenborgh, <span id=\"cite_ITEM-20317-1\" name=\"citation\"><a href=\"#ITEM-20317-1\">Hansen et al. (1981)<\/a><\/span>). Observations are the GISTEMP LOTI annual figures and 5 year mean. Last updated: 27 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>Hansen et al (1988)<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/hansen_2025.png\" alt=\"Time series from 1955 to present of Hansen et al (1988) climate model hindcasts to 1984, and projections beyond (from three scenarios), compared to observed temperatures. The observed temperatures are just a little below Scenario B.\" class=\"wp-image-26353 lazyload\" style=\"--smush-placeholder-width: 3508px; --smush-placeholder-aspect-ratio: 3508\/2479;width:799px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2007\/05\/hansens-1988-projections\/\">Original discussion (2007)<\/a>, <a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2018\/06\/30-years-after-hansens-testimony\/\">Last discussion (2018)<\/a>. Scenarios from <span id=\"cite_ITEM-20317-2\" name=\"citation\"><a href=\"#ITEM-20317-2\">Hansen et al. (1988)<\/a><\/span>. Observations are the GISTEMP LOTI annual figures. Trends from 1984: GISTEMP: 0.23\u00baC\/dec, Scenarios A, B, C: 0.35, 0.29, 0.15\u00baC\/dec respectively (all 95% CI ~\u00b10.02 or 0.03). Last updated: 24 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>CMIP3 (circa 2004)<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip3_2025.png\" alt=\"\" class=\"wp-image-26328 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:758px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2015\/06\/noaa-temperature-record-updates-and-the-hiatus\/\">Last discussion (2015)<\/a>. 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: 22 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>CMIP5 (circa 2011)<\/strong><\/p>\n\n\n<div class=\"wp-block-image wp-image-24677\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_sat_2025.png\" alt=\"Time series from 1979 of CMIP5 climate model hindcasts to 2005, and projections beyond, compared to observed temperatures. The long term trends in the models are a good fit to the actual temperatures.\" class=\"wp-image-26355 lazyload\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 3508px; --smush-placeholder-aspect-ratio: 3508\/2479;\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2015\/06\/noaa-temperature-record-updates-and-the-hiatus\/\">Last discussion (2015)<\/a>. Model spread is the 95% envelope of true global mean surface temperature anomalies from all CMIP5 historical simulations (using the RCP4.5 projection post-2005). Forcing adjustment is updated from <span id=\"cite_ITEM-20317-3\" name=\"citation\"><a href=\"#ITEM-20317-3\">Schmidt et al. (2014)<\/a><\/span>. Observations 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: 24 Jan 2026.<\/em><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_blend_2025.png\" alt=\"Time series from 1979 of CMIP5 climate model hindcasts of blended SST\/SAT to 2005, and projections beyond, compared to observed temperatures. The long term trends in the models are a good fit to the actual temperatures.\" class=\"wp-image-26356 lazyload\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 3508px; --smush-placeholder-aspect-ratio: 3508\/2479;\" \/><\/figure>\n<\/div>\n\n\n<p><em>As above, but using the blended <a href=\"http:\/\/www-users.york.ac.uk\/\/~kdc3\/papers\/robust2015\/methods.html\">SST\/SAT product<\/a> from the CMIP5 models produced by <span id=\"cite_ITEM-20317-4\" name=\"citation\"><a href=\"#ITEM-20317-4\">Cowtan et al (2015)<\/a><\/span> instead of the pure SAT field. Note that this makes about a 0.05\u00baC difference in 2022 (compared to a 0.1\u00baC difference estimated from the forcings adjustment above). Last updated: 24 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>CMIP6 (circa 2021)<\/strong><\/p>\n\n\n\n<p>The last phase of CMIP went from ~2019 to 2025. These models used observed boundary conditions (GHG levels, deforestation, solar, volcanoes etc.) up to 2014, and projections based on the Shared Socioeconomic Pathways (SSPs) from 2015 onward. The same caveat with respect to the comparison to the blended SAT\/SST observations stands as with CMIP5, but this is a relatively small effect (i.e. it&#8217;s expected to be around 0.05\u00baC in 2022).\u00a0 Note however, that <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2021\/08\/notallmodels\/\">some CMIP6 models<\/a> have climate sensitivities outside both the CMIP5 range and the <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2020\/07\/climate-sensitivity-a-new-assessment\/\">range constrained by observations<\/a>.\u00a0 Thus in these figures, we plot the full mean (1 ensemble member per model) and the mean of a subset of the models that have a transient climate response (TCR) within the likely constrained range [1.4,2.2]\u00baC as assessed by <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2021\/08\/the-ipcc-sixth-assessment-report\/\">IPCC AR6<\/a> (<span id=\"cite_ITEM-20317-5\" name=\"citation\"><a href=\"#ITEM-20317-5\">Hausfather et al., 2022<\/a><\/span>). <\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" width=\"2504\" height=\"2030\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmiip6_sat_2025.png\" alt=\"\" class=\"wp-image-26329 lazyload\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025.png 2504w, https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025-300x243.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025-600x486.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025-150x122.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025-1536x1245.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmiip6_sat_2025-2048x1660.png 2048w\" data-sizes=\"(max-width: 2504px) 100vw, 2504px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 2504px; --smush-placeholder-aspect-ratio: 2504\/2030;\" \/><figcaption class=\"wp-element-caption\"><em>Surface temperature changes in CMIP6 models, using a screened ensemble and a fuller ensemble (37 models).<\/em> <em>Last updated: 22 Jan 2026.<\/em><\/figcaption><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" width=\"2504\" height=\"2030\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_sat_trends_2025.png\" alt=\"Histogram of trends from 1979 to present of CMIP6 climate model hindcasts to 2014, and projections beyond, compared to observed SAT products.\" class=\"wp-image-26330 lazyload\" style=\"--smush-placeholder-width: 2504px; --smush-placeholder-aspect-ratio: 2504\/2030;width:690px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025.png 2504w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025-300x243.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025-600x486.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025-150x122.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025-1536x1245.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_sat_trends_2025-2048x1660.png 2048w\" data-sizes=\"(max-width: 2504px) 100vw, 2504px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-text-align-center\"><em>Model spread is the 95% envelope of surface air temperature anomalies using 37 model simulations from the historical runs and SSP2-4.5. TCR values used in the screen are Hausfather et al. (2022). Last updated: 22 Jan 2026.<br><\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"msu\">Satellite-derived atmospheric temperatures<\/h3>\n\n\n\n<p>Where available, we compare models to TMT, TLT, Corrected-TMT and SSU levels, using the same screening for CMIP6 as described above. <\/p>\n\n\n\n<p><strong>TMT (global and tropical means) (timeseries and trends) <\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_tmt_2025.png\" alt=\"\" class=\"wp-image-26359 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:714px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_tmt_trop_2025.png\" alt=\"\" class=\"wp-image-26361 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:700px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" width=\"2560\" height=\"1844\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_tmt_trends_2025-1-scaled.png\" alt=\"Histogram of trends from 1979 to present of CMIP5 climate model hindcasts to 2005, and projections beyond, compared to observed mid-troposphere temperatures (TMT).\" class=\"wp-image-26362 lazyload\" style=\"--smush-placeholder-width: 2560px; --smush-placeholder-aspect-ratio: 2560\/1844;width:680px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-scaled.png 2560w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-300x216.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-600x432.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-150x108.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-1536x1106.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trends_2025-1-2048x1475.png 2048w\" data-sizes=\"(max-width: 2560px) 100vw, 2560px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" width=\"2560\" height=\"1844\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip5_tmt_trop_trends_2025-scaled.png\" alt=\"\" class=\"wp-image-26363 lazyload\" style=\"--smush-placeholder-width: 2560px; --smush-placeholder-aspect-ratio: 2560\/1844;width:672px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-scaled.png 2560w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-300x216.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-600x432.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-150x108.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-1536x1106.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmip5_tmt_trop_trends_2025-2048x1475.png 2048w\" data-sizes=\"(max-width: 2560px) 100vw, 2560px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"http:\/\/www.realclimate.org\/index.php\/archives\/2016\/05\/comparing-models-to-the-satellite-datasets\/\">Original discussion (Jan 2017)<\/a>. Mid-troposphere satellite products from UAH, RSS, NOAA STAR\u00a0and UW (Po-Chedley et al, &#8220;UW&#8221; tropical values only &#8211; updated to 2022 only). Model values use synthetic MSU\/AMSU-TMT weightings, spread is 95% envelope of simulations, but this product only exists up to 2025, so these figures won&#8217;t be updated again. Last updated: 25 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>Corrected-TMT (Tropical means) (timeseries and trends) <\/strong><\/p>\n\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_tmtc_2025.png\" alt=\"Tropical TMT-Corrected temperature  in CMIP6 models compared to observations from 1979 to present.\" class=\"wp-image-26349 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:720px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_tmtc_trends_2025.png\" alt=\"Histogram of tropical TMT-Corrected temperature trends in TCR-screened CMIP6 models compared to observations from 1979 to present. \" class=\"wp-image-26350 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:696px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2023\/03\/some-new-cmip6-msu-comparisons\/\" title=\"Some new CMIP6 MSU comparisons\">Original discussion Mar 2023<\/a><\/em>. <em>The TMT-corrected diagnostic (where the TMT is adjusted by the lower stratospheric changes (TLS)) in a 24-model subsample of the CMIP6 database (<span id=\"cite_ITEM-20317-6\" name=\"citation\"><a href=\"#ITEM-20317-6\">Po-Chedley et al., 2021<\/a><\/span>) compared to RSS v4, UAH v6.1 and NOAA STAR v5. Plots includes the full ensemble, and then a subset of models that have a TCR within the IPCC AR6 likely range. Model values use synthetic TMT-corrected weightings, spread is 95% envelope of simulations. Last updated: 23 Jan 2026.<\/em><\/p>\n\n\n\n<p><strong>TLT (timeseries and trends)<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" width=\"2504\" height=\"2030\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_tlt_2025.png\" alt=\"\" class=\"wp-image-26331 lazyload\" style=\"--smush-placeholder-width: 2504px; --smush-placeholder-aspect-ratio: 2504\/2030;width:792px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025.png 2504w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025-300x243.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025-600x486.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025-150x122.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025-1536x1245.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_2025-2048x1660.png 2048w\" data-sizes=\"(max-width: 2504px) 100vw, 2504px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img decoding=\"async\" width=\"2504\" height=\"2030\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_tlt_trends_2025.png\" alt=\"Histogram of TLT trends in CMIP6 models, showing the full ensemble and the TCR-screened subset, along with the the trends from RSS, UAH and NOAA STAR.\" class=\"wp-image-26332 lazyload\" style=\"--smush-placeholder-width: 2504px; --smush-placeholder-aspect-ratio: 2504\/2030;width:764px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025.png 2504w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025-300x243.png 300w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025-600x486.png 600w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025-150x122.png 150w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025-1536x1245.png 1536w, https:\/\/www.realclimate.org\/images\/cmp_cmip6_tlt_trends_2025-2048x1660.png 2048w\" data-sizes=\"(max-width: 2504px) 100vw, 2504px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em>The Temperature of the Lower Troposphere (TLT) diagnostic in a 38-model subsample of the CMIP6 database <span id=\"cite_ITEM-20317-7\" name=\"citation\"><a href=\"#ITEM-20317-7\">(McKitrick and Christy, 2020)<\/a><\/span> compared to RSS v4, UAH v6.1 and NOAA STAR v5. Plots includes the full ensemble, and then a subset of models that have a TCR within the IPCC AR6 likely range. Model values use synthetic TLT weightings, spread is 95% envelope of simulations. Last updated: 22 Jan 2026.<\/em><\/p>\n\n\n\n<p id=\"ssu\"><strong>Stratospheric temperature changes <\/strong><\/p>\n\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_ssu_2025.png\" alt=\"Time-series from 1979 to present of three SSU channels showing comparison of observations and CMIP6 climate models.\" class=\"wp-image-26345 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:732px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_ssu_trends_2025.png\" alt=\"Histogram of 1979 to present linear trends in global SSU channels in CMIP6 models and observations.\" class=\"wp-image-26347 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:720px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><em><a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2023\/05\/cmip6-not-so-sudden-stratospheric-cooling\/\" title=\"CMIP6: Not-so-sudden stratospheric cooling\">Original discussion 5\/21\/23<\/a><\/em>. <em>Global mean SSU trends for three channels (NOAA-STAR v3.0) compared to a 9-member subset of the CMIP6 archive. Last updated 23 Jan 2026.<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"sst\"><strong>Global SST changes<\/strong><\/h3>\n\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_sst_2025.png\" alt=\"Sea surface temperature trends in CMIP6 models compared to observations from 1979 to present. The TCR-screened simulations line up very nicely with the observations.\" class=\"wp-image-26365 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:744px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n<div class=\"wp-block-image is-resized\">\n<figure class=\"aligncenter size-full\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/cmp_cmip6_sst_trends_2025.png\" alt=\"Histogram of 1979 to present linear trends in global SST in CMIP6 models and observations. The TCR-screened models line up nicely with observed trends, but some models (e.g. CanESM5) are warming too fast.\" class=\"wp-image-26366 lazyload\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;width:728px;height:auto\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><\/figure>\n<\/div>\n\n\n<p><a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2023\/03\/some-new-cmip6-msu-comparisons\/\" title=\"Some new CMIP6 MSU comparisons\"><em>Original discussion 3\/19\/2023<\/em><\/a>.<em>Global mean SST trends in CMIP6 compared to HadSST4.2 and ERSST6. As above, models are screened using the TCR criterion. The models are a 15-model subset from the <a href=\"https:\/\/cmip6.science.unimelb.edu.au\/\" title=\"U. Melbourne collation\">U. Melbourne collation<\/a>. Last updated 27 Jan 2026.<\/em><\/p>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"si\">Arctic <strong>Sea Ice Extent\/Area<\/strong><\/h3>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"600\" height=\"432\" data-src=\"https:\/\/www.realclimate.org\/images\/\/si_cmip3_2025-600x432.png\" alt=\"Graph with two lines and observations for CMIP3 sea ice extent in Mar and Sep, along with the observations from 1979 to the latest year.\" class=\"wp-image-26335 lazyload\" data-srcset=\"https:\/\/www.realclimate.org\/images\/si_cmip3_2025-600x432.png 600w, https:\/\/www.realclimate.org\/images\/si_cmip3_2025-300x216.png 300w, https:\/\/www.realclimate.org\/images\/si_cmip3_2025-150x108.png 150w, https:\/\/www.realclimate.org\/images\/si_cmip3_2025-1536x1106.png 1536w, https:\/\/www.realclimate.org\/images\/si_cmip3_2025-2048x1475.png 2048w\" data-sizes=\"(max-width: 600px) 100vw, 600px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 600px; --smush-placeholder-aspect-ratio: 600\/432;\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"600\" height=\"432\" data-src=\"https:\/\/www.realclimate.org\/images\/\/si_cmip5_2025-600x432.png\" alt=\"Graph with two lines and observations for CMIP5 sea ice extent in Mar and Sep, along with the observations from 1979 to the latest year.\" class=\"wp-image-26336 lazyload\" data-srcset=\"https:\/\/www.realclimate.org\/images\/si_cmip5_2025-600x432.png 600w, https:\/\/www.realclimate.org\/images\/si_cmip5_2025-300x216.png 300w, https:\/\/www.realclimate.org\/images\/si_cmip5_2025-150x108.png 150w, https:\/\/www.realclimate.org\/images\/si_cmip5_2025-1536x1106.png 1536w, https:\/\/www.realclimate.org\/images\/si_cmip5_2025-2048x1475.png 2048w\" data-sizes=\"(max-width: 600px) 100vw, 600px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 600px; --smush-placeholder-aspect-ratio: 600\/432;\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"600\" height=\"432\" data-src=\"https:\/\/www.realclimate.org\/images\/\/si_cmip6_2025-600x432.png\" alt=\"Graph with two lines and observations for CMIP6 sea ice extent in Mar and Sep, along with the observations from 1979 to latest year.\" class=\"wp-image-26337 lazyload\" data-srcset=\"https:\/\/www.realclimate.org\/images\/si_cmip6_2025-600x432.png 600w, https:\/\/www.realclimate.org\/images\/si_cmip6_2025-300x216.png 300w, https:\/\/www.realclimate.org\/images\/si_cmip6_2025-150x108.png 150w, https:\/\/www.realclimate.org\/images\/si_cmip6_2025-1536x1106.png 1536w, https:\/\/www.realclimate.org\/images\/si_cmip6_2025-2048x1475.png 2048w\" data-sizes=\"(max-width: 600px) 100vw, 600px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 600px; --smush-placeholder-aspect-ratio: 600\/432;\" \/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p><em><a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2025\/05\/predicted-arctic-sea-ice-trends-over-time\/\" title=\"Predicted Arctic sea ice trends over time\">Original discussion 5\/31\/2025<\/a>. Arctic sea ice timeseries (percent change from 1979-1988) from CMIP3, CMIP5 (extent) and CMIP6 (area) compared to NSIDC observations (updated to <a href=\"ftp:\/\/sidads.colorado.edu\/DATASETS\/NOAA\/G02135\/\" title=\"v4\">v4<\/a>). Last updated 22 Jan 2026.<\/em><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" data-src=\"https:\/\/www.realclimate.org\/images\/\/si_trends_2025.png\" alt=\"\" class=\"wp-image-26338 lazyload\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 2806px; --smush-placeholder-aspect-ratio: 2806\/2021;\" \/><figcaption class=\"wp-element-caption\"><em>Summary of % trends in sea ice extent across three model generations compared to NSIDC observations (v4), and including a screening for TCR in CMIP6. [Updated: 1\/22\/2026]<\/em><\/figcaption><\/figure>\n<\/div><h2>References<\/h2>\n    <ol>\n    <li><a name='ITEM-20317-0'><\/a>\nZ. Hausfather, H.F. Drake, T. Abbott, and G.A. Schmidt, \"Evaluating the Performance of Past Climate Model Projections\", <i>Geophysical Research Letters<\/i>, vol. 47, 2020. <a href=\"http:\/\/dx.doi.org\/10.1029\/2019GL085378\">http:\/\/dx.doi.org\/10.1029\/2019GL085378<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-1'><\/a>\nJ. Hansen, D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, and G. Russell, \"Climate Impact of Increasing Atmospheric Carbon Dioxide\", <i>Science<\/i>, vol. 213, pp. 957-966, 1981. <a href=\"http:\/\/dx.doi.org\/10.1126\/science.213.4511.957\">http:\/\/dx.doi.org\/10.1126\/science.213.4511.957<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-2'><\/a>\nJ. Hansen, I. Fung, A. Lacis, D. Rind, S. Lebedeff, R. Ruedy, G. Russell, and P. Stone, \"Global climate changes as forecast by Goddard Institute for Space Studies three\u2010dimensional model\", <i>Journal of Geophysical Research: Atmospheres<\/i>, vol. 93, pp. 9341-9364, 1988. <a href=\"http:\/\/dx.doi.org\/10.1029\/JD093iD08p09341\">http:\/\/dx.doi.org\/10.1029\/JD093iD08p09341<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-3'><\/a>\nG.A. Schmidt, D.T. Shindell, and K. Tsigaridis, \"Reconciling warming trends\", <i>Nature Geoscience<\/i>, vol. 7, pp. 158-160, 2014. <a href=\"http:\/\/dx.doi.org\/10.1038\/ngeo2105\">http:\/\/dx.doi.org\/10.1038\/ngeo2105<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-4'><\/a>\nK. Cowtan, Z. Hausfather, E. Hawkins, P. Jacobs, M.E. Mann, S.K. Miller, B.A. Steinman, M.B. Stolpe, and R.G. Way, \"Robust comparison of climate models with observations using blended land air and ocean sea surface temperatures\", <i>Geophysical Research Letters<\/i>, vol. 42, pp. 6526-6534, 2015. <a href=\"http:\/\/dx.doi.org\/10.1002\/2015GL064888\">http:\/\/dx.doi.org\/10.1002\/2015GL064888<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-5'><\/a>\nZ. Hausfather, K. Marvel, G.A. Schmidt, J.W. Nielsen-Gammon, and M. Zelinka, \"Climate simulations: recognize the \u2018hot model\u2019 problem\", <i>Nature<\/i>, vol. 605, pp. 26-29, 2022. <a href=\"http:\/\/dx.doi.org\/10.1038\/d41586-022-01192-2\">http:\/\/dx.doi.org\/10.1038\/d41586-022-01192-2<\/a>\n\n\n<\/li>\n<li><a name='ITEM-20317-6'><\/a>\nS. Po-Chedley, J.T. Fasullo, N. Siler, Z.M. Labe, E.A. Barnes, C.J.W. Bonfils, and B.D. Santer, \"Internal variability and forcing influence model\u2013satellite differences in the rate of tropical tropospheric warming\", <i>Proceedings of the National Academy of Sciences<\/i>, vol. 119, 2022. <a href=\"http:\/\/dx.doi.org\/10.1073\/pnas.2209431119\">http:\/\/dx.doi.org\/10.1073\/pnas.2209431119<\/a>\n\n\n<\/li>\n<\/ol>\n\n<\/div> <!-- kcite-section 20317 -->","protected":false},"excerpt":{"rendered":"<p>Since we have been periodically posting updates since 2009 of climate 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\/AMSU satellite products from CMIP5 [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":25834,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"class_list":{"0":"post-20317","1":"page","2":"type-page","3":"status-publish","4":"has-post-thumbnail","6":"entry"},"aioseo_notices":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/pages\/20317","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/comments?post=20317"}],"version-history":[{"count":107,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/pages\/20317\/revisions"}],"predecessor-version":[{"id":26369,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/pages\/20317\/revisions\/26369"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media\/25834"}],"wp:attachment":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media?parent=20317"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}