A new study by researchers at the University of California San Diego has explored whether geoengineering could be used to reduce the impact of future ‘super El Niño’ events.
With an anticipated super El Niño looming, researchers at the university’s Scripps Institution of Oceanography, explored the potential of marine cloud brightening, a weather-altering technique that increases the reflectivity of clouds to reduce the amount of solar radiation absorbed by the Earth.
The study, Could Geoengineering Work to Tamp Down Super El Niños?, was prompted by observations made following the ‘Black Summer’ bushfires in Australia in 2019 and 2020, which saw aerosols contained in the associated smoke interact with clouds over the southeastern Pacific Ocean, increasing their reflectivity and contributing to weather patterns similar to La Niña.
The research team simulated what might have happened if a similar cloud-brightening effect had occurred before the major El Niño events of 1997 and 2015, suggesting that targeted marine cloud brightening in the southeastern Pacific could reduce the intensity of super El Niño conditions.
Natural variability
“As long-term anthropogenic warming and short-term natural variability often compound to produce extreme weather events, our findings suggest it may be worth considering interventions which target natural variability, rather than the forced response to greenhouse gases,” the authors commented.
“Such an approach could result in similar physical risk reduction with shorter duration interventions that carry less sociotechnical risk than a sustained deployment.”
Social concerns
However, the authors warn that further research will be needed before any real-world deployment can be considered, with geoengineering long considered a controversial measure, due to the unintended consequences it could cause.
“One of the biggest social concerns around geoengineering is the fact that if we use it to reduce long-term climate risks, we have to deploy it continuously for an indefinite period of time,” commented Scripps Oceanography researcher Jessica Wan. “If we could target natural variability, we could get some of the benefits of geoengineering without having to employ it indefinitely.”
The study was published in the Science Advances journal. Read more here and here.
