Marine Cloud Brightening May Mitigate Super El Niño Events
A recent study suggests that marine cloud brightening (MCB), a geoengineering technique involving the seeding of clouds with seawater aerosols, could mitigate the effects of extreme El Niño events by reducing solar heating over the eastern Pacific. This intervention aims to dampen global temperature spikes typically associated with El Niño, according to research published by Wan et al. in June 2024.
The study highlights that by targeting low-level marine stratocumulus clouds, MCB could potentially reduce the intensity of El Niño events. However, the research, which remains unpeer-reviewed, cautions about the possibility of significant unintended consequences.
Further research by Chen et al. in 2024 indicates that deploying MCB over 5% of the ocean could lead to a global cooling of approximately 1°C. However, this could also trigger a La Niña-like response, characterized by cooler tropical Pacific temperatures and altered global precipitation patterns. The study notes an increase in rainfall over land and a decrease over oceans.
Despite the potential benefits, a Nature Climate Change study from June 2024 warns that the effectiveness of regional MCB may decline by 2050, potentially exacerbating heatwaves in remote regions such as Europe. The study suggests that while present-day seeding could reduce dangerous heat by 55% in the North Pacific and 16% in southern California, these benefits may diminish over time.
Additionally, research by Yu et al. published in February 2026 indicates that annual seeding of eastern Pacific clouds from 2020 to 2100 could stabilize global mean surface air temperature and precipitation at 2020 levels. However, the long-term impacts and feasibility of such interventions remain uncertain.