Generative artificial intelligence improves projections of climate extremes

Climate change is amplifying extreme weather and climate events worldwide [1]. Anthropogenic greenhouse gas emissions have disrupted the Earth's climate system, driving more frequent and severe heatwaves [2], cold spells [3], heavy precipitation [4], agricultural droughts [5], and tropical cyclones (TCs) [6]. Between 2016 and 2024, daily land temperature records show that extreme heat events occurred over four times more often than expected, while cold records declined by half [7]. These unprecedented shifts threaten human health [8, 9], infrastructure [10, 11], food security [12], biodiversity [13], and global economies [14, 15]. Therefore, reliable climate projections are essential for effective mitigation and adaptation strategies [16-18]. The Coupled Model Intercomparison Project (CMIP) [19] provides a foundation for global climate projections. Since its launch in 1995, CMIP has coordinated systematic evaluation of coupled general circulation models (GCMs). CMIP5 introduced Representative Concentration Pathways (RCPs), while CMIP6 extended this framework by incorporating Shared Socioeconomic Pathways (SSPs) through ScenarioMIP, enabling consistent simulations of emissions and socioeconomic trajectories to 2100 and facilitating integrated assessment of climate risks [20]. These advances have greatly enhanced the scientific and policy relevance of climate projections.