A Climate Fix So Risky, Critics Say Don’t Even Study It

The idea: Spray aerosols into the sky to block some sunshine. To advocates, it’s an emergency measure; to opponents, a massive gamble.

Blocking Out the Sun to Fight Climate Change

Here’s a scary thought: What if we’re too late to stop devastating climate change? We talk a lot about prevention. Harvard physicist David Keith says we should be thinking about triage.

Keith is researching solar geoengineering—spraying aerosols into the upper atmosphere that act as tiny mirrors, reflecting some sunlight back to space and cooling the planet. His lab built a mini-atmosphere to test how different aerosols might react.

While other countries have research programs on solar geoengineering, in the U.S., just studying it has been controversial. Critics argue that the potential unknown effects could be dire and that a cooling remedy could weaken our will to curb emissions.

Keith says we need to know more about geoengineering before we dismiss it.

“It’s a deep question,” he says, “why people seem to be more concerned about deliberate tinkering that actually aims to reduce environmental risk than they are about all sorts of hideous ways we’ve damaged the environment.”

For more of the Unsolvable series, see: The Bio-Plastics Revolution Starts in This Lab

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