Quantifying the Disproportionate Contributions of High-Income Groups to the Emergence of Climate Extremes

Climate change impacts are unevenly distributed, with those least responsible often bearing the brunt of its effects. This study quantifies how greenhouse gas emissions from high-income groups have influenced present-day global mean temperature levels and the frequency of temperature and potential drought extremes worldwide. We deploy an emulator-based modeling framework to systematically attribute changes in regional climate extremes to emissions from different wealth groups. 

Our results show that the wealthiest 10% globally contributed about 6.5 times the global average to warming (0.40°C ± 0.16°C), while the top 1% contributed 20 times the average (0.12°C ± 0.05°C). These disproportionate contributions are further amplified for extreme events, with the top 10% contributing about 7 times more to the emergence of 1-in-100 year heat and potential drought events than the global average. Emissions from the wealthiest 10% in the United States and China are associated with a two- to three-fold increase in the frequency of heat and drought extremes across vulnerable regions. This research provides a quantitative basis for discussions on climate equity and justice by linking wealth disparities to concrete climate change impacts. Our findings have important implications for designing effective and equitable climate policies that address both mitigation and adaptation needs. The study's application of a coupled MAGICC-MESMER-M-TP framework illustrates how emulator approaches can inform policy debates on differential responsibilities and capabilities in climate action, potentially supporting more targeted and just approaches to emissions reduction and climate finance.