Can geoengineering ease El Niño impacts

Satellite images from early June 2026 reveal a band of unusually warm water across the equatorial Pacific, signaling that El Niño is gaining strength. The climate pattern, which appears every two to seven years, is expected to bring droughts, heat waves, and extreme weather to nearly every continent in the coming months. This year’s event has already set new temperature records in the ocean.

New research suggests it may be possible to weaken El Niño before it fully forms by brightening clouds off the coast of South America.

Spraying salt to cool the ocean

The proposal, published Wednesday in Science Advances, examines marine cloud brightening. The method involves spraying sea salt into the lower atmosphere to increase cloud reflectivity. Less sunlight would reach the ocean surface, cooling the water and potentially reducing El Niño’s intensity.

A team at the University of Chicago simulated two of the strongest El Niño events on record—1997-1998 and 2015-2016. Their findings showed the technique could lower ocean warming if applied early, around May or June. That window matches when forecasters can predict the event’s strength with confidence.

Jessica Wan, the study’s lead author and a postdoctoral fellow at the university, described the work as an effort to explore whether short-term benefits of geoengineering could be achieved without long-term risks.

Economic forecasts estimate El Niño will cause $84 trillion in global losses over the 21st century. The potential for a targeted intervention is clear, but so are the risks.

Unknowns and ethical dilemmas

Critics argue the technology remains untested and that altering a natural climate cycle could lead to unforeseen consequences. Michael McPhaden, a retired senior scientist with NOAA, called the idea risky. El Niño has influenced global weather for millions of years, and he questioned whether human intervention could account for its complexity.

Concerns about the study’s scope also emerged. The simulations covered only two years, after which the models lose reliability. Raymond Pierrehumbert, a planetary scientist at the University of Oxford, warned that predicting the long-term effects of weakening El Niño is difficult. For instance, reducing its strength might trigger a stronger La Niña the following year, creating different disruptions.

Ethical concerns add another layer of complexity. El Niño does not affect all regions equally. It harms agriculture in parts of Africa and Asia but reduces Atlantic hurricanes, benefiting the U.S. Gulf Coast and the Caribbean. McPhaden noted that modifying El Niño would shift these outcomes, requiring global agreement on who bears the costs and who gains. Such decisions have long stalled climate negotiations.

The logistical hurdles

The proposal remains theoretical for now. Many experts argue that the technology is impractical. Wan hopes further research could improve understanding of the approach. If successful, she sees it as a temporary measure to reduce the worst impacts while longer-term solutions, like cutting fossil fuel emissions, are developed.

As El Niño intensifies, the urgency to mitigate its effects grows. The debate over geoengineering is just beginning, raising questions not only about whether it can work but whether it should be attempted at all.