{"id":442178,"date":"2026-05-01T13:01:15","date_gmt":"2026-05-01T20:01:15","guid":{"rendered":"https:\/\/climatescience.press\/?p=442178"},"modified":"2026-05-02T04:18:04","modified_gmt":"2026-05-02T11:18:04","slug":"rcp8-5-is-officially-dead-climate-science-finally-retires-its-implausible-extreme-scenario","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=442178","title":{"rendered":"RCP8.5 Is Officially Dead: Climate Science Finally Retires Its Implausible Extreme Scenario"},"content":{"rendered":"<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"687\" height=\"1024\" data-attachment-id=\"442179\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=442179\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?fit=784%2C1168&amp;ssl=1\" data-orig-size=\"784,1168\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"0 RCP8.5 Is Officially Dead Climate Science Finally Retires Its Implausible Extreme Scenario\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?fit=687%2C1024&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?resize=687%2C1024&#038;ssl=1\" alt=\"\" class=\"wp-image-442179\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?resize=687%2C1024&amp;ssl=1 687w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?resize=201%2C300&amp;ssl=1 201w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?resize=768%2C1144&amp;ssl=1 768w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?resize=640%2C953&amp;ssl=1 640w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?w=784&amp;ssl=1 784w\" sizes=\"auto, (max-width: 687px) 100vw, 687px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\"><strong>The RCP8.5 (and its close equivalent SSP5-8.5) has effectively been retired from the core framework for the next round of major climate modeling (CMIP7, feeding into IPCC AR7).<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is a meaningful course correction after years of criticism. <strong>Roger Pielke Jr.<\/strong> called it<strong> &#8220;the most significant development in climate research in decades&#8221;<\/strong> in his recent Substack post.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Representative Concentration Pathways (RCPs) <\/strong>were developed for CMIP5 (used heavily in IPCC AR5). <strong>RCP8.5<\/strong> assumed a radiative forcing of +8.5 W\/m\u00b2 by 2100 relative to pre-industrial\u2014 the highest of the standard set. It implied very high greenhouse gas concentrations, often described (misleadingly) as &#8220;business-as-usual&#8221; or a no-new-policies baseline.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In practice<\/strong>, it became the <strong>most-cited scenario <\/strong>in thousands of impact studies (floods, wildfires, agriculture, health, sea level, etc.) because it produced the strongest &#8220;signal&#8221; for detecting climate effects amid natural variability\u2014useful for model diagnostics but problematic when treated as the default future.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A new paper by Van Vuuren et al. (2026) for the ScenarioMIP framework (guiding CMIP7) introduces seven updated scenarios and<strong> drops RCP8.5\/SSP5-8.5 and SSP3-7.0<\/strong> as core cases. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Reasons cited:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Falling costs of renewables (solar\/wind).<\/li>\n\n\n\n<li>Expansion of climate policies.<\/li>\n\n\n\n<li>Actual emission trends and energy outlooks (e.g., IEA current\/stated policies scenarios) that diverge sharply from the extreme high-coal pathway.<\/li>\n\n\n\n<li>The high-end scenarios are now deemed implausible on socioeconomic and technological grounds.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Critics like Pielke, Justin Ritchie<\/strong>, and others had documented for years that RCP8.5 diverged from reality even in the near term: observed\/post-2005 emissions, coal trends, and energy projections tracked much lower. It required assumptions (e.g., coal super-abundance ignoring reserves and economics) that were already strained by the 2010s. IPCC AR6 itself noted high-emissions scenarios had &#8220;low likelihood&#8221; and weren&#8217;t typical &#8220;no policy&#8221; baselines, though legacy use persisted.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For over a decade, RCP8.5 was <strong>over-weighted<\/strong> in research, media, and policy communication\u2014often without clear probability labels or caveats that it was an <strong>extreme\/high-risk <\/strong>pathway, not the expected one. This inflated perceptions of imminent catastrophe and justified aggressive mitigation timelines that downplayed trade-offs (energy reliability, costs, development in poor countries). Self-correction in science is good: dropping implausible baselines improves credibility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>CMIP7 (Coupled Model Intercomparison Project Phase 7)<\/strong> is the next major iteration of the international effort to coordinate Earth System Model (ESM) simulations for understanding past, present, and future climate. Its <strong>ScenarioMIP<\/strong> component defines the core future emissions\/concentration\/land-use pathways that drive these models. The key paper is Van Vuuren et al. (2026) in Geoscientific Model Development, which formalizes a new set of <strong>seven scenarios<\/strong> for CMIP7 (feeding into IPCC AR7 and broader research).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Roger Pielke Jr.<\/strong> is a political scientist and policy scholar (University of Colorado Boulder emeritus, now AEI senior fellow) specializing in the intersection of science, policy, disasters, and climate. He accepts the core physics\u2014humans influence the climate via greenhouse gases, and the planet has warmed\u2014but has long criticized how climate science is communicated, how scenarios are used (or misused), the politicization of research, and the overemphasis on aggressive mitigation at the expense of adaptation and innovation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">_____________________________________________________________________________________<\/p>\n\n\n\n<p class=\"has-large-font-size wp-block-paragraph\"><strong>RCP8.5 is Officially Dead<\/strong><\/p>\n\n\n\n<p class=\"has-medium-font-size wp-block-paragraph\"><strong>The most significant development in climate research in decades<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">From <a href=\"https:\/\/rogerpielkejr.substack.com\/p\/rcp85-is-officially-dead\">The Honest Broker<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By <a href=\"https:\/\/substack.com\/@rogerpielkejr\">Roger Pielke Jr.<\/a><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"723\" data-attachment-id=\"442192\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=442192\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?fit=1254%2C1254&amp;ssl=1\" data-orig-size=\"1254,1254\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?fit=723%2C723&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=723%2C723&#038;ssl=1\" alt=\"\" class=\"wp-image-442192\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=1024%2C1024&amp;ssl=1 1024w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=300%2C300&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=150%2C150&amp;ssl=1 150w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=768%2C768&amp;ssl=1 768w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=640%2C640&amp;ssl=1 640w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=1200%2C1200&amp;ssl=1 1200w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=800%2C800&amp;ssl=1 800w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=600%2C600&amp;ssl=1 600w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=400%2C400&amp;ssl=1 400w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=200%2C200&amp;ssl=1 200w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=450%2C450&amp;ssl=1 450w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=60%2C60&amp;ssl=1 60w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=550%2C550&amp;ssl=1 550w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?resize=50%2C50&amp;ssl=1 50w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-1.png?w=1254&amp;ssl=1 1254w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><em>\u201c[T]he high-emissions RCP8.5 scenario has long been described as a \u201cbusiness-as-usual\u201d pathway with a continued emphasis on energy from fossil fuels with no climate policies in place. This remains 100% accurate . . .\u201c \u2014 from 2021,&nbsp;<\/em><a href=\"https:\/\/issues.org\/climate-scenarios-reality-pielke-jr-ritchie-forum\/\">Chris Field (co-chair of IPCC WG2 AR5) and Marcia McNutt (president of U.S. National Academy of Sciences, Engineering, and Medicine )<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The international committee responsible for the official scenarios that feed into climate modeling that are the basis for most projective climate research and the assessments of the Intergovernmental Panel on Climate Change (IPCC) has just published the next generation of climate scenarios.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Big news: The new framework has&nbsp;<em>eliminated<\/em>&nbsp;the most extreme scenarios that have dominated climate research over much of the past several decades \u2014 specifically, RCP8.5, SSP5-8.5, and SSP3-7.0. This is an absolutely huge development in climate science which will have lasting impacts across research and policy.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The future is not what it used to be.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Today\u2019s post commends the researchers who have brought climate scenarios more in line with current understandings, but also raises some significant continuing issues with the scenarios.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s get started . . .<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The new scenarios come from the Coupled Model Intercomparison Project (CMIP) \u2014 a project of the World Climate Research Programme (WCRP), co-sponsored by the World Meteorological Organization, the International Science Council, and UNESCO\u2019s Intergovernmental Oceanographic Commission.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Under CMIP, now in its seventh iteration, sits another little-known committee with responsibility for developing the scenarios necessary for earth system models to project future climate.<a href=\"https:\/\/rogerpielkejr.substack.com\/p\/rcp85-is-officially-dead#footnote-1\">1<\/a>&nbsp;That committee \u2014 called ScenarioMIP \u2014 just&nbsp;<a href=\"https:\/\/gmd.copernicus.org\/articles\/19\/2627\/2026\/\">published<\/a>&nbsp;the new scenario framework that will underpin the IPCC\u2019s Seventh Assessment Report (AR7) and much of the research that it will draw upon.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In a paper released earlier this month,&nbsp;<a href=\"https:\/\/doi.org\/10.5194\/gmd-19-2627-2026\">Van Vuuren et al. (VVetal26)<\/a>&nbsp;introduce a new set of seven scenarios. The authors write of the obsolete high end emissions scenarios (emphasis added):<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cFor the 21st century, this range will be smaller than assessed before: on the high-end of the range, the CMIP6 high emission levels (quantified by SSP5-8.5) have become&nbsp;<strong>implausible<\/strong>, based on trends in the costs of renewables, the emergence of climate policy and recent emission trends.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Read that again \u2014 The high end scenarios are&nbsp;<em><a href=\"https:\/\/iopscience.iop.org\/article\/10.1088\/1748-9326\/ac4ebf\">Implausible<\/a><\/em>.<a href=\"https:\/\/rogerpielkejr.substack.com\/p\/rcp85-is-officially-dead#footnote-2\">2<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I disagree that the implausibility of the high-end scenarios resulted from the falling costs of renewables or the emergence of climate policy, but that is a debate for another day.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">What matters today is that the group with official responsibility for developing climate scenarios for the IPCC and broader research community has now admitted that the scenarios that have dominated climate research, assessment, and policy during the past two cycles of the IPCC assessment process are implausible: They describe impossible futures.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tens of thousands of research papers have been \u2014 and continue to be \u2014 published using these scenarios, a similar number of media headlines have amplified their findings, and governments and international organization have built these implausible scenarios into policy and regulation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We now know that all of this is built on a foundation of sand.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">What changed<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The new CMIP7 ScenarioMIP framework offers seven scenarios spanning a range from \u201cVERY LOW\u201d through \u201cHIGH.\u201d The current naming convention drops the radiative-forcing target labels of the SSP era \u2014 there is no \u201c8.5\u201d scenario, and no \u201c7.0\u201d scenario, but as I\u2019ll show below, each scenario has a radiative forcing level in 2100.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">I ran the available new scenarios (HIGH, MEDIUM, LOW, and VERY LOW) through the FaIR calibrated and constrained ensemble that&nbsp;<a href=\"https:\/\/zenodo.org\/records\/14382495\">Sanderson and Smith (2025)<\/a>&nbsp;used to characterize the CMIP7 set (FaIR v. 2.2.0 as described in their README file). I then ran each of the five tier-1 SSPs through the same emulator with identical parameters to ensure that the results are apples-to-apples. The full methodology, data, and code is in the appendix to this post.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The headline results follow.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>CO\u2082 emissions: fossil fuels and industry, 2000\u20132100<\/strong><\/h4>\n\n\n\n<figure class=\"wp-block-image size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"404\" data-attachment-id=\"442195\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=442195\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?fit=2264%2C1264&amp;ssl=1\" data-orig-size=\"2264,1264\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?fit=723%2C404&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=723%2C404&#038;ssl=1\" alt=\"\" class=\"wp-image-442195\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=1024%2C572&amp;ssl=1 1024w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=300%2C167&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=768%2C429&amp;ssl=1 768w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=1536%2C858&amp;ssl=1 1536w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=2048%2C1143&amp;ssl=1 2048w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=640%2C357&amp;ssl=1 640w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?resize=1200%2C670&amp;ssl=1 1200w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?w=1446&amp;ssl=1 1446w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-2.png?w=2169&amp;ssl=1 2169w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The chart above shows fossil-fuel and industry CO\u2082 emissions for four CMIP7 scenarios alongside the five tier-1 SSPs and the two main reference scenarios from the 2025&nbsp;<a href=\"https:\/\/www.iea.org\/reports\/world-energy-outlook-2025\">IEA World Energy Outlook<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Note the massive gap between the new HIGH and SSP5-8.5. The new HIGH reaches 71 Gt CO\u2082\/yr in 2100 \u2014 far below SSP5-8.5 at 128 Gt in 2100. Nothing in the CMIP7 set comes close to SSP5-8.5. The new HIGH also sits below SSP3-7.0 by about 9% in terms of cumulative emissions to 2100. Note also the gap between MEDIUM (solid yellow) and SSP2-4.5 (dashed yellow), which I\u2019ll return to below.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Both of the most recent IEA near term scenarios \u2014 which run to 2050 \u2014 fall below MEDIUM and SSP2-4.5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The table below compares the CMIP7 scenarios to their closest AR6 analogues, showing that the overall range has constricted. The higher scenarios have come down and the lower scenarios have come up \u2014 except VERY LOW, which moved down.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"293\" data-attachment-id=\"442197\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=442197\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?fit=2235%2C905&amp;ssl=1\" data-orig-size=\"2235,905\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?fit=723%2C293&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=723%2C293&#038;ssl=1\" alt=\"\" class=\"wp-image-442197\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=1024%2C415&amp;ssl=1 1024w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=300%2C121&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=768%2C311&amp;ssl=1 768w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=1536%2C622&amp;ssl=1 1536w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=2048%2C829&amp;ssl=1 2048w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=640%2C259&amp;ssl=1 640w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?resize=1200%2C486&amp;ssl=1 1200w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?w=1446&amp;ssl=1 1446w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/image-3.png?w=2169&amp;ssl=1 2169w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">2100 effective radiative forcing and end-of-century temperature<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The table below lists AR6 and CMIP7 scenarios from highest to lowest 2100 radiative forcing. The middle column shows the average global temperature change from an 1850-1900 baseline, under the climate emulator used by CMIP7. The right column shows the average temperature change for the SSPs as projected by the IPCC AR6.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><em>Read the full story <a href=\"https:\/\/rogerpielkejr.substack.com\/p\/rcp85-is-officially-dead\">here<\/a>.<\/em><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The RCP8.5 (and its close equivalent SSP5-8.5) has effectively been retired from the core framework for the next round of major climate modeling (CMIP7, feeding into IPCC AR7).<\/p>\n","protected":false},"author":121246920,"featured_media":442179,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691822729,691842706,691842708,691842709,691819137,691824483,691822454],"class_list":{"0":"post-442178","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-climate-modeling","9":"tag-cmip7-coupled-model-intercomparison-project-phase-7","10":"tag-extreme-high-risk","11":"tag-most-cited-scenario","12":"tag-rcp8-5","13":"tag-roger-pielke-jr","14":"tag-scenariomip","16":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2026\/05\/0-RCP8.5-Is-Officially-Dead-Climate-Science-Finally-Retires-Its-Implausible-Extreme-Scenario.jpg?fit=784%2C1168&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1R1U","jetpack-related-posts":[{"id":383069,"url":"https:\/\/climatescience.press\/?p=383069","url_meta":{"origin":442178,"position":0},"title":"The Great Climate Science Swindle Goes On","author":"uwe.roland.gross","date":"06\/13\/2025","format":false,"excerpt":"It will be remembered as the greatest mass delusion in the history of the world \u2013 that CO2, the life of plants, was considered for a time to be a deadly poison. Harvard Emeritus Professor Richard Lindzen","rel":"","context":"In \"climate alarmism\"","block_context":{"text":"climate alarmism","link":"https:\/\/climatescience.press\/?tag=climate-alarmism"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0Screenshot-2025-06-11-235046.jpeg?fit=1200%2C698&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0Screenshot-2025-06-11-235046.jpeg?fit=1200%2C698&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0Screenshot-2025-06-11-235046.jpeg?fit=1200%2C698&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0Screenshot-2025-06-11-235046.jpeg?fit=1200%2C698&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0Screenshot-2025-06-11-235046.jpeg?fit=1200%2C698&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":318163,"url":"https:\/\/climatescience.press\/?p=318163","url_meta":{"origin":442178,"position":1},"title":"Climate Cooking:\u00a0 from Roger Pielke Jr.","author":"uwe.roland.gross","date":"04\/16\/2024","format":false,"excerpt":"Pielke Jr. starts with an update on his important work in challenging flawed narratives of catastrophe.","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0Climate_Politics_Roger_Pielke_Jr-1007x1024-1.jpg?fit=1007%2C1024&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0Climate_Politics_Roger_Pielke_Jr-1007x1024-1.jpg?fit=1007%2C1024&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0Climate_Politics_Roger_Pielke_Jr-1007x1024-1.jpg?fit=1007%2C1024&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0Climate_Politics_Roger_Pielke_Jr-1007x1024-1.jpg?fit=1007%2C1024&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":318639,"url":"https:\/\/climatescience.press\/?p=318639","url_meta":{"origin":442178,"position":2},"title":"The \u201cAmazing Tale\u201d of How Three Billionaires Plunged the World into Climate Catastrophism","author":"uwe.roland.gross","date":"04\/17\/2024","format":false,"excerpt":"Do you think that the constant catastrophising of weather and climate in the mainstream media, politics and science has just appeared by accident? Over the last few years, the BBC and the Guardian, as of one mind, decided to float improbable \u2018tipping point\u2019 scares under cover of \u2018scientists say\u2019, while\u2026","rel":"","context":"In \"Billionaires\"","block_context":{"text":"Billionaires","link":"https:\/\/climatescience.press\/?tag=billionaires"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0sun-1.webp?fit=1200%2C917&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0sun-1.webp?fit=1200%2C917&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0sun-1.webp?fit=1200%2C917&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0sun-1.webp?fit=1200%2C917&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/04\/0sun-1.webp?fit=1200%2C917&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":308272,"url":"https:\/\/climatescience.press\/?p=308272","url_meta":{"origin":442178,"position":3},"title":"New York Post Misses the Boat on Sea Level Rise","author":"uwe.roland.gross","date":"03\/14\/2024","format":false,"excerpt":"A story published in the New York Post (NYP) on March 3rd 2024 by Carl Campanile has the alarming headline:\u00a0Sea levels around NYC could surge up to 13 inches in 2030s due to climate change: state study.\u00a0The story and study cited is false, because it relies on an impossible climate\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0AssetAccess3-5.webp?fit=1200%2C675&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0AssetAccess3-5.webp?fit=1200%2C675&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0AssetAccess3-5.webp?fit=1200%2C675&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0AssetAccess3-5.webp?fit=1200%2C675&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0AssetAccess3-5.webp?fit=1200%2C675&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":307625,"url":"https:\/\/climatescience.press\/?p=307625","url_meta":{"origin":442178,"position":4},"title":"Climate Model Bias 6: WGII","author":"uwe.roland.gross","date":"03\/13\/2024","format":false,"excerpt":"The previous parts of this series investigated model bias in the CMIP6 models and in their interpretation in AR6 WGI. This part looks at model bias in AR6 WGII,\u00a0Climate Change 2022: Impacts, Adaptation, and Vulnerability.","rel":"","context":"In \"AR6 WGII\"","block_context":{"text":"AR6 WGII","link":"https:\/\/climatescience.press\/?tag=ar6-wgii"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0-Climate-Model-Bias-6.jpeg?fit=1200%2C900&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0-Climate-Model-Bias-6.jpeg?fit=1200%2C900&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0-Climate-Model-Bias-6.jpeg?fit=1200%2C900&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0-Climate-Model-Bias-6.jpeg?fit=1200%2C900&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/03\/0-Climate-Model-Bias-6.jpeg?fit=1200%2C900&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":339568,"url":"https:\/\/climatescience.press\/?p=339568","url_meta":{"origin":442178,"position":5},"title":"Roger Pielke Jr. details \u2018The Top Five Climate Science Scandals\u2019: Study claiming no \u2018climate crisis\u2019 retracted \u2018for not for being wrong\u2026but instead for expressing views that are politically unhelpful\u2019","author":"uwe.roland.gross","date":"08\/14\/2024","format":false,"excerpt":"The science community has shown a willingness to retract a climate science paper \u2014 in this case not for being wrong in any substantive way, but instead for expressing views that are politically unhelpful. In 2022, a group of Italian scientists published a paper that summarized the IPCC\u2019s conclusions on\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/08\/0Screenshot-2024-08-14-152601.png?fit=1200%2C699&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/08\/0Screenshot-2024-08-14-152601.png?fit=1200%2C699&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/08\/0Screenshot-2024-08-14-152601.png?fit=1200%2C699&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/08\/0Screenshot-2024-08-14-152601.png?fit=1200%2C699&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/08\/0Screenshot-2024-08-14-152601.png?fit=1200%2C699&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/442178","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/users\/121246920"}],"replies":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=442178"}],"version-history":[{"count":25,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/442178\/revisions"}],"predecessor-version":[{"id":442213,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/442178\/revisions\/442213"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/442179"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=442178"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=442178"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=442178"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}