Abstract
Europe has experienced severe droughts that impacted electricity generation from both renewable and fossil sources. Yet, the response of national electricity systems to drought and the resulting impacts on emissions of CO₂ and air pollutants remain insufficiently understood. This study combines monthly historical electricity generation data (2017–2023) with runoff anomalies, used as a proxy for drought conditions, across 25 European countries. A regression-based counterfactual analysis is applied to quantify the country-level response of electricity systems to drier-than-average conditions. Estimated drought-induced changes in fossil-based generation are subsequently translated into emissions of greenhouse gases and air pollutants using fuel- and country-specific emission factors. We find that electricity generation from hydropower and other renewables is reduced during dry periods, while reliance on fossil fuels and imports increases. Drought induced 141±35 million tonnes of CO₂-equivalent emissions between 2017 and 2023, corresponding to 31 % of the emissions that Europe could release by 2040 under its most ambitious climate goals. Emissions are mainly driven by increased use of natural gas (48 %), coal (22 %), lignite (21 %), and imports (8 %). In France and Portugal, drought-induced emissions account for around 10 % of total fossil-based electricity emissions. The estimated monetized social cost of these emissions is 26 billion USD. Emissions of air pollutants show an average increase of about 2.5 %, though they widely vary across countries. These findings underscore the need for targeted adaptation strategies to reduce the power sector’s vulnerability to drought and to maintain progress toward energy security and decarbonization targets