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To this year Niño is shaping up to be among the The strongest everIt is set to create chaotic weather around the world.
A new study suggests that there may be a way to mitigate some of the effects of El Niño and future global warming: dimming the sun.
The El Niño phenomenon develops naturally in the tropical Pacific every few years, due to weak trade winds that push heat from the ocean towards the coast of South America. This suggests the possibility of higher than average global temperatures, as well as drought in some areas, heavy rains and floods in others, and more hurricanes in the Pacific Ocean. In addition to global warming caused by burning fossil fuels, a strong El Niño could mean hundreds of billions in economic losses.
The new study suggests that solar energy conversion could cool the ocean and help mitigate El Niño events before they become too strong, avoiding the worst impacts.
“El Niño is one of those things where something happens in the tropical Pacific Ocean and then it rearranges the way the entire global atmosphere holds energy for that year,” says Katherine Reeke, co-author of the study published Wednesday in the journal Science Advances and a climate scientist at the University of California, San Diego and the Scripps Institution of Oceanography. “It is the maximum pressure point in the climate system.”
Rickey and her colleagues looked into using marine cloud brightening, or MCB, as a way to dim the sun in the Pacific Ocean. This technique requires spraying seawater on marine clouds to enhance the reflectivity of the clouds. While some pilot projects and randomized controlled trials have tested the effectiveness of this technique, they have been on very small scales.
MCB is one of a few different products Solar geoengineering methods They are intended to reflect sunlight back into space. Other methods, such as using aircraft for injection Aerosols into the stratospherecan only work globally. But MCB has the potential to be a regional cooling solution.
To overcome the lack of MCB experiments, the researchers looked at a recent natural phenomenon that mimics it: the catastrophic 2019-2020 Australian bushfire season. More than 10,000 wildfires broke out across the country, producing nearly 10,000 wildfires. Million metric tons of smoke. This represents one of the largest smoke inputs into the stratosphere ever observed by humans using satellite technology.
While the effects of this massive amount of smoke were complex, previous research had shown that it helped trigger a rare triple dip The girl– The opposite phase of El Niño – thanks in part to reflective particles in the smoke.
Rickey says this event enabled her and her co-authors to address the question they had been mulling over for years about whether regional interventions could help mitigate the pressure that events like El Niño have placed on the global climate system. The researchers created a model based on the MCB effects of Australian bushfires, and compared it to two different historical El Niño events to observe its effects. Modeling showed that reducing the amount of sunlight reaching the surface of the Pacific Ocean would have dramatically reduced the size and global impact of El Niño events.
Traditionally, geoengineering techniques have been seen as a way to cool the entire planet, acting as a counterbalance to humans’ use of fossil fuels – albeit highly controversially. The new study suggests that some forms of geoengineering might be better used to target regional events, such as El Niño. Doing so would avoid—or at least reduce the risk of—the compounding effects of El Niño on human-induced warming.
“The idea of having to maintain geoengineering indefinitely gives a lot of people pause,” says Rick. “We all realize that collaboration on this scale would be very complex in the world we live in.” “This is a completely different way of thinking about geoengineering.”
