{"id":3216,"date":"2026-03-27T11:30:00","date_gmt":"2026-03-27T10:30:00","guid":{"rendered":"https:\/\/www.scientistrebellion.nl\/?p=3216"},"modified":"2026-03-27T11:39:33","modified_gmt":"2026-03-27T10:39:33","slug":"worst-case-outcomes-of-moderate-global-warming","status":"publish","type":"post","link":"https:\/\/www.scientistrebellion.nl\/index.php\/en\/2026\/03\/27\/worst-case-outcomes-of-moderate-global-warming\/","title":{"rendered":"Worst-case outcomes of moderate global warming"},"content":{"rendered":"\n

Moderate global warming creates a risk of climate impacts that are more severe than the most-likely impacts of high global warming.<\/strong><\/p>\n\n\n\n

Summary of a News & Views article in Nature<\/em> (25 March 2026) by Rachel Warren, 1<\/a><\/sup> discussing a paper by Bevacqua\u202fet\u202fal. in the same issue. 2<\/a><\/sup><\/p>\n\n\n\n

The Paris Agreement targets a rise of less than\u202f2\u202f\u00b0C above pre\u2011industrial levels, yet the uncertainty inherent in climate\u2011model ensembles means that even this \u201cmoderate\u201d warming can generate impacts as severe as those usually associated with higher temperature increases. Bevacqua\u202fet\u202fal. (p.\u202f946) demonstrate that, at a 2\u202f\u00b0C rise, exposure of critical systems\u2014such as the global breadbasket, densely populated urban areas, and fire\u2011prone forests\u2014to climate\u2011related hazards (drought, intense precipitation, and wildfire\u2011favourable weather) can match or exceed levels projected for 3\u202f\u00b0C\u20134\u202f\u00b0C warming. This finding underlines the need for climate policy to incorporate worst\u2011case scenarios, not only the most likely outcomes.<\/p>\n\n\n\n

The authors\u2019 methodology aligns with the World Climate Research Programme\u2019s \u201cSafe Landing\u201d recommendations, which call for the identification of low\u2011probability, high\u2011impact risks with global ramifications. Using CMIP6 model outputs, they quantified regional temperature changes and mapped spatial patterns of climate\u2011impact drivers for each model. They introduced a \u201cglobal climatic impact\u2011driver\u201d metric that captures how exposure to each hazard changes per degree of warming. By ranking models on this metric and selecting the top and bottom 10\u202f% as worst\u2011 and best\u2011case outcomes, they highlighted the breadth of possible futures.<\/p>\n\n\n\n

This is a low-probability, high-impact risk that we should not take.<\/p>\n\n\n\n

Their analysis shows that, even at 2\u202f\u00b0C, the most adverse model outcomes can be more extreme than the average projections for 3\u202f\u00b0C or 4\u202f\u00b0C. Consequently, a precautionary approach\u2014aiming well below the 2\u202f\u00b0C threshold\u2014is required to avoid such extremes with high confidence. Policymakers should therefore consider both the most probable and the less likely, more severe outcomes when designing mitigation and adaptation strategies.<\/p>\n\n\n\n

While global climate sensitivity (the temperature response to a CO\u2082 doubling) has received considerable policy attention, uncertainties in regional exposure to hazards have been less scrutinized. Existing risk assessments usually present error margins but seldom explore the tail\u2011end of the distribution. Bevacqua\u202fet\u202fal. argue that risk assessments need to focus on extreme outcomes, especially in regions that are pivotal for food security or ecosystem services. Their work could inform updates to the IPCC\u2019s \u201cburning\u2011embers\u201d diagrams, which colour\u2011code risk levels based on evidence strength, magnitude, likelihood, permanence, and importance of impacts.<\/p>\n\n\n\n

\"\"
Burning ember diagrams for low to medium adaptation.<\/strong> (More details on each burning ember are provided in Sections 13.10.2.1\u201313.10.2.4 and SM13.10. Some burning embers are shown again in Figures 13.29\u201313.34 alongside burning embers with high adaptation.)<\/em> 3<\/a><\/sup><\/figcaption><\/figure>\n\n\n\n

Future research should extend this extreme\u2011risk framework to other vital systems\u2014ocean health, coastal zones, human health, and infrastructure\u2014and incorporate vulnerability and adaptive capacity, which the current study omitted. The United Nations Environment Programme projects that, under current policies, warming will reach about\u202f2.8\u202f\u00b0C, underscoring the urgency of rapid mitigation. To keep warming below 2\u202f\u00b0C and limit exposure to the worst\u2011case scenarios identified by Bevacqua\u202fet\u202fal., global CO\u2082 emissions must fall to net\u2011zero by the early 2050s, demanding swift transitions from fossil fuels to low\u2011 or zero\u2011carbon energy sources.<\/p>\n\n\n\n

<\/p>\n

  1. Warren, R. (2026). Extreme climate outcomes could still occur with just 2 \u00b0C of global warming. Nature<\/em>, 651<\/em>(8107), 888\u2013890. https:\/\/doi.org\/10.1038\/d41586-026-00640-7[↩<\/a>]<\/span><\/li>
  2. Bevacqua, E., Fischer, E., Sillmann, J., & Zscheischler, J. (2026). Moderate global warming does not rule out extreme global climate outcomes. Nature<\/em>, 651<\/em>(8107), 946\u2013953. https:\/\/doi.org\/10.1038\/s41586-026-10237-9[↩<\/a>]<\/span><\/li>
  3. Figure 13.28 in Bednar-Friedl, B., R. Biesbroek, D.N. Schmidt, P. Alexander, K.Y. B\u00f8rsheim, J. Carnicer, E. Georgopoulou, M. Haasnoot, G. Le Cozannet, P. Lionello, O. Lipka, C. M\u00f6llmann, V. Muccione, T. Mustonen, D. Piepenburg, and L. Whitmarsh, 2022: Europe. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. <\/em>Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [H.-O. P\u00f6rtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegr\u00eda, M. Craig, S. Langsdorf, S. L\u00f6schke, V. M\u00f6ller, A. Okem, B. Rama (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 1817\u20131927, doi:10.1017\/9781009325844.015.[↩<\/a>]<\/span><\/li><\/ol>","protected":false},"excerpt":{"rendered":"

    Moderate global warming creates a risk of climate impacts that are more severe than the most-likely impacts of high global warming. Summary of a News & Views article in Nature (25 March 2026) by Rachel Warren, 1 discussing a paper by Bevacqua\u202fet\u202fal. in the same issue. 2 The Paris Agreement targets a rise of less … Lees verder<\/a><\/p>\n","protected":false},"author":10,"featured_media":3227,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":true,"iawp_total_views":39,"footnotes":""},"categories":[49],"tags":[],"class_list":["post-3216","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-climate-news"],"_links":{"self":[{"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/posts\/3216","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/comments?post=3216"}],"version-history":[{"count":3,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/posts\/3216\/revisions"}],"predecessor-version":[{"id":3228,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/posts\/3216\/revisions\/3228"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/media\/3227"}],"wp:attachment":[{"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/media?parent=3216"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/categories?post=3216"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.scientistrebellion.nl\/index.php\/wp-json\/wp\/v2\/tags?post=3216"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}