Dimming the sun to curb El Niño: a Scripps study proposes regional solar geoengineering in the Pacific

The article, written by Molly Taft in WIRED (July 8, 2026), begins with concern over the current El Niño episode, which according to the text is on track to become one of the strongest on record and which will cause chaotic weather patterns around the world. Against that backdrop, the piece presents a new study published that same Wednesday in the journal Science Advances that raises a striking idea: using solar geoengineering on a regional, one-off basis to moderate the intensity of future El Niño episodes, rather than resorting to it as a permanent global cooling tool.

The El Niño phenomenon arises naturally in the tropical Pacific every few years, when weaker trade winds push ocean heat toward the coast of South America. This alters the global distribution of temperatures and precipitation: it favors above-average temperatures, droughts in some regions, heavy rains and flooding in others, and an increase in cyclones in the Pacific. Combined with warming caused by fossil fuels, a strong El Niño can generate economic losses of hundreds of billions of dollars, according to the article.

The lead author cited, Katherine Ricke, a climatologist at the University of California, San Diego and the Scripps Institution of Oceanography, describes El Niño as 'one of those phenomena where something happens in the tropical Pacific and reorders the way the entire global atmosphere retains energy that year,' calling it 'the ultimate pressure point in the climate system.' Ricke and her co-authors explored the possibility of using the technique known as 'marine cloud brightening' (MCB) to dim solar radiation specifically over the Pacific. The technique consists of spraying seawater toward low clouds to increase their reflectivity and thereby bounce more sunlight back into space before it warms the ocean.

Unlike other solar geoengineering methods, such as injecting aerosols into the stratosphere using aircraft —which according to the article can only be deployed on a global scale—, MCB has the distinctive feature of being applicable regionally, which opens the door to targeted interventions in specific areas of the ocean rather than sustained planetary cooling.

Since real-world MCB trials have so far only been carried out on a small scale (the text mentions pilot projects and randomized controlled trials of very limited scope), the researchers turned to a natural experiment that mimicked its effects: the catastrophic 2019-2020 Australian wildfire season. Those fires —more than 10,000 blazes that released nearly a million metric tons of smoke— constituted one of the largest injections of smoke into the stratosphere ever observed by satellite. Previous research cited in the article indicates that this smoke, with its reflective particles, helped trigger a rare consecutive 'triple' La Niña, the phenomenon opposite to El Niño.

Drawing on that episode, Ricke and her team built a model based on the cloud-brightening effects produced by the Australian fires and applied it retrospectively to two historical El Niño episodes. According to the article, the simulation showed that reducing the amount of sunlight reaching the surface of the Pacific would have significantly reduced the magnitude of those El Niño episodes and, with it, their global climate impact.

The work thus fits within a conceptual shift in how solar geoengineering has traditionally been understood: not as a permanent, global counterweight to fossil fuel use —an option that carries strong opposition because of the difficulty of sustaining the international cooperation it would require over decades— but as an intervention bounded in time and space, aimed at cushioning specific events like El Niño and preventing their effects from adding to those of human-caused global warming. Ricke herself sums it up by noting that 'the idea of having to sustain geoengineering indefinitely gives many people pause' because everyone understands how complicated cooperation on that scale would be in today's world, and that this approach represents 'a completely different way of thinking about geoengineering.'

The article does not shy away from the skepticism surrounding these techniques. It recalls that proposals such as stratospheric aerosol injection, or more speculative ideas like space mirrors, have sparked distrust among scientists, policymakers and the public, especially because of their unpredictability —altering the climate can have unintended consequences— and their potential to generate political instability. The text notes that a regionalized approach like the one proposed is likely to run into the same problems, though it appears scientifically feasible or, at least, worthy of further study.

For contrast, WIRED includes the assessment of Andrew Dessler, a professor of atmospheric science at Texas A&M University, who was not involved in the study. Dessler considers that 'the thesis seems fairly reasonable,' but warns that putting it into practice would be 'a political nightmare' that could lead to conflict or even war if something went wrong in what would be a worst-case scenario. He further stresses that climate models are imperfect and there is the possibility of creating an unforeseen problem worse than the one it was meant to solve. In his words, it is 'a really interesting article' from which he says he learned, but he clarifies that he would not call it a good idea ready to be implemented.

Ricke herself agrees with that caution: she acknowledges that many things remain to be worked out from the models before attempting something like this in the real world. Even so, she argues that this kind of research could prove crucial for the future if humanity fails to curb fossil fuel pollution, summing up the underlying motivation of solar geoengineering in one sentence: it is being researched because we could end up in a world that needs it.

Overall, the article announces neither an imminent application nor a settled scientific consensus, but rather presents a modeling study that opens a line of research —regional solar geoengineering targeting specific climate phenomena like El Niño— and immediately subjects it to the scrutiny of a critical outside voice, making clear that this is a hypothesis to be studied and not a public policy recommendation.