Building on recent studies like Stefan Rahmstorf et al.'s analysis showing a doubling of Earth's warming rate to ~0.36°C per decade since 2014, scientists disagree on whether reductions in aerosol pollution or natural fluctuations are driving the speedup. Nearly all agree warming has accelerated, but views differ on causes, rate, and future trajectory—with implications for climate sensitivity and adaptation.
Earth's surface warming held steady at about 0.18°C per decade until the 2010s, then quickened. Record heat in 2023 (hottest by 0.17°C), 2024 (first year exceeding 1.5°C above pre-industrial levels), and 2025—with European heatwaves and cyclones in South-East Asia and Jamaica—drove extreme weather: deadly Libya floods, Mozambique/Mexico cyclones, and wildfires in Canada, Chile, Greece, and Hawaii.
Samantha Burgess of the EU’s Copernicus Climate Change Service attributes much recent warming to cleaner air: “The atmosphere is cleaner, so more solar radiation is coming in,” after a 40% global drop in sulphur dioxide since the mid-2000s. Key factors include China's 75% aerosol cut since its 2008 'war on pollution' and International Maritime Organization shipping emission rules.
James Hansen of Columbia University called this a 'Faustian bargain' in a 2023 paper, arguing aerosols had masked CO2-driven warming, with post-2010 acceleration to 0.32°C per decade. Estimates vary: IPCC at 0.24°C, recent models at 0.29°C, and Rahmstorf/Foster at 0.36°C since 2014.
Natural influences include the 2020 solar maximum, 2022 Tonga eruption (injecting 146 million tonnes of stratospheric water vapour), and 2023-2024 El Niño. Michael Mann of the University of Pennsylvania counters: “Recent warmth... is entirely consistent with standard climate model simulations,” rejecting major acceleration claims. Helge Goessling's study linked 0.2°C of 2023 heat to declining low clouds, hinting at new feedbacks. Zeke Hausfather of Berkeley Earth cautions that higher sensitivity could mean 3.7°C warming this century under current policies, rendering some regions uninhabitable.
