DMF paper: Iran team explores the impact of global warming and SRM on La Niña & El Niño

sea surface temperature anomaly
Sea surface temperature anomaly, sea-surface temperatures in May 2022 and May 2023 compared to a reference period 1985–1993. Credits: ESA (Data source: NOAA)

The climate system responds to changing temperatures in various ways, including fairly periodic changes between warm and cold conditions in the tropical Pacific Ocean (El Niño and La Niña), but also, the longer period oscillations in the North Pacific and Atlantic oceans. These patterns, or teleconnections, are the second biggest drivers of weather variability after the seasons, and have enormous impacts on global weather, wildfires, fish stocks and countless other human and ecological footprints. A key question is, how might these patterns change as the climate warms. 

A former DMF team from Iran, co-led by Dr Khalil Karami and Dr Abolfazl Rezaei from Iran’s Institute for Advanced Studies in Basic Sciences (IASBS), analysed how future global warming may drive these important global patterns, and if solar radiation modification (SRM) would exacerbate or mitigate these changes. Their analysis shows that while the tropical Pacific pattern is relatively insensitive to the greenhouse gas changes, both the North Atlantic and North Pacific patterns are more affected. While SRM tends to reduce the impacts of greenhouse warming in most cases, the decadal and longer period impacts of greenhouse warming in the North Atlantic may be accentuated by SRM.

This new research detects how SRM might influence key modes of the Earth’s climate and how these teleconnections may impact weather around the world. Future research will need to address these questions with specific impact models and explore the physical mechanisms behind these changes.

Changes in global teleconnection patterns under global warming and stratospheric aerosol intervention scenarios in Atmospheric Chemistry and Physics by Abolfazl Rezaei, Khalil Karami, Simone Tilmes, and John C. Moore

*The Iran team was contracted and funded by the World Academy of Sciences (TWAS), a unit of UNESCO, as part of the Solar Radiation Management Governance Initiative (SRMGI)