Darken the sun to fight against global warming

Researchers are proposing an ingenious yet untested approach to tackling climate change. They plan to spray sun-drying chemicals into the Earth's atmosphere.

In a study conducted by Harvard and Yale universities, scientists used a technique called aerosol injection into the stratosphere (SAI), which is expected to halve the rate of global warming. This technique involves spraying many sulphate particles in the lower stratosphere at altitudes up to 12 miles.

For spraying, a special type of aircraft, balloons or large naval style guns will be used. Although the technology remains hypothetical, no existing aircraft can be adapted.

Scientists have noted, "The development of a new tanker with a large payload capacity would be neither technologically difficult nor prohibitively expensive. The total cost of launching a hypothetical system in about 15 years is about $ 3.5 billion, with an operating cost of $ 2.25 billion a year over a 15-year period. "

"There will also be risks of potential risks, including coordination between several countries in both hemispheres, and ISI techniques could jeopardize yields, drought, or extreme weather conditions."

Philippe Thalmann of the Ecole Polytechnique Fédérale de Lausanne, an expert in climate change economics, told CNN: "From the point of view of the climate economy, the management of solar radiation remains a much worse solution than greenhouse gas emissions: more expensive and more expensive. risky in the long run. "

David Archer of the Department of Geophysical Sciences at the University of Chicago said, "The technical climate problem in this way is that it is only a temporary dressing covering a problem that will persist forever, in fact hundreds of thousands of years ago for fossils. CO2 fuel to finally disappear naturally. "

"It would be tempting to continue to postpone cleaning up our energy system, but we would leave the planet with some form of support for life. If a future generation did not pay its climate bill, it would get all our warmings at the same time. "

The study is published in the journal Environmental Research Letters.