Controversial geoengineering research effort receives billionaires' support: 'They don't see the government being able to step up'

Imagine a 100-square-foot "sun shield" floating in space, deflecting a small amount of sunlight away from Earth.

Sound like science fiction? It could become a reality.

The Asher Space Research Institute at Technion-Israel Institute of Technology is poised to build this prototype shield.

The effort is part of a growing wave of research into solar geoengineering — controversial proposals to cool the planet by blocking or reflecting some of the sun's rays. And it's attracting new interest and funding from Silicon Valley billionaires like Bill Gates and George Soros.

Last month, climate scientists, environmentalists, and philanthropists quietly convened in San Francisco to gear up for an influx of tech money into solar geoengineering studies. The meeting sought to establish best practices to guide the coming surge in research.

Solar geoengineering concepts range from spraying reflective particles into the stratosphere to altering cloud cover. In theory, they could curb rising temperatures by reducing the sunlight absorbed by Earth.

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Proponents argue this could buy critical time to slash the carbon and methane pollution overheating our planet. Curbing pollution remains essential, as solar geoengineering wouldn't stop other harms like ocean acidification.

However, many scientists caution that sustained global efforts to dim the sun could disrupt weather patterns and ecosystems. Abruptly stopping could also cause temperatures to rebound rapidly. More research is needed to understand the risks and benefits.

Environmentalists are grappling with how to approach solar geoengineering responsibly. "We need to put this in a scientific perspective," former Rep. Jerry McNerney told Scientific American. "Does solar radiation management make sense? Is it more dangerous than climate change?"

McNerney also cheered those who are "taking up the responsibility to do this because they don't see the government being able to step up to the degree that's needed to do this properly."

As climate impacts hit harder and clean energy efforts ramp up, groups like the Environmental Defense Fund see an opening to seriously engage on this thorny topic. The goal: Shine a light on the science and guide research and governance efforts.

While the technology is still, in McNerney's words, a "very explosive issue" politically, those taking the lead hope to spark an informed public dialogue. After all, our ability to protect communities and create a cooler future may depend on it.

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