{"id":106026,"date":"2025-03-26T02:49:00","date_gmt":"2025-03-26T01:49:00","guid":{"rendered":"https:\/\/www.sonnenseite.com\/?p=106026"},"modified":"2025-03-26T10:29:57","modified_gmt":"2025-03-26T09:29:57","slug":"amplified-global-heating-risk-due-to-climate-and-carbon-cycle-feedbacks","status":"publish","type":"post","link":"https:\/\/www.sonnenseite.com\/en\/science\/amplified-global-heating-risk-due-to-climate-and-carbon-cycle-feedbacks\/","title":{"rendered":"Amplified global heating risk due to climate and carbon cycle feedbacks"},"content":{"rendered":"\n
Global heating over this millennium could exceed previous estimates due to carbon cycle feedback loops. This is the conclusion of a new study by the Potsdam Institute for Climate Impact Research (PIK). <\/p>\n\n\n\n
The analysis shows that achieving the Paris Agreement\u2019s aim of limiting global warming to well below 2\u00b0C is only feasible under very low emission scenarios, and if climate sensitivity is lower than current best estimates. The paper is the first to make long-term projections over the next 1,000 years while accounting for currently established carbon cycle feedbacks, including methane.<\/p>\n\n\n\n
\u201cOur study demonstrates that even in emission scenarios typically considered \u2018safe\u2019, where global warming is generally considered to remain below 2\u00b0C, climate and carbon cycle feedbacks, like the thawing of permafrost, could lead to temperature increases substantially above this threshold,\u201d says PIK scientist Christine Kaufhold, lead author of the paper published in Environmental Research Letters<\/em>. \u201cWe found that peak warming could be much higher than previously expected under low-to-moderate emission scenarios.\u201d<\/p>\n\n\n\n
The study projects the long-term impacts of human-induced climate change and underlines that even small changes in emissions could lead to far greater warming than previously anticipated, further complicating efforts to meet the Paris Agreement targets. \u201cThis highlights the urgent need for even faster carbon reduction and removal efforts,\u201d Kaufhold says.<\/p>\n\n\n\n
Most studies are too short-term to capture peak warming, as they end by 2100 or 2300. The team used PIK\u2019s newly developed Earth system model CLIMBER-X to simulate future climate scenarios over the next millennium under three low-to-moderate emissions trajectories \u2013 pathways that align with recent decarbonisation trends. CLIMBER-X integrates key physical, biological and geochemical processes, including atmospheric and oceanic conditions. It also represents an interactive carbon cycle, including methane, to simulate how the Earth system responds to different climate forcings, such as human-made greenhouse gas emissions.<\/p>\n\n\n\n
The study\u2019s simulations consider a range of equilibrium climate sensitivities (ECSs) between 2\u00b0C and 5\u00b0C, defined as \u201cvery likely\u201d by the IPCC. The ECS is a critical measure in climate science, estimating the global temperature rise associated with a doubling of CO2<\/sub> concentrations. \u201cOur results show that the Paris Agreement\u2019s goal is only achievable under very low emission scenarios and if the ECS is lower than current best estimates of 3o<\/sup>C,\u201dsays PIK scientist Matteo Willeit, co-author of the study. \u201cIf the ECS exceeds 3\u00b0C, carbon reduction must accelerate even more quickly than previously thought to keep the Paris target within reach.\u201d The paper highligths the important role ECS plays in shaping future climate outcomes while revealing the risks of failing to accurately estimate ECS. It emphasises the urgent need to more accurately quantify this metric and better constrain it.<\/p>\n\n\n\n
\u201cOur research makes it unmistakably clear: Today\u2019s actions will determine the future of life on this planet for centuries to come. The window for limiting global warming to below 2\u00b0C is rapidly closing. We are already seeing signs that the Earth system is losing resilience, which may trigger feedbacks that increase climate sensitivity, accelerate warming and increase deviations from predicted trends. To secure a liveable future, we must urgently step up our efforts to reduce emissions. The Paris Agreement\u2019s goal is not just a political target, it is a fundamental physical limit,\u201d concludes PIK director Johan Rockstr\u00f6m, co-author of the paper.<\/p>\n\n\n\n