US scientists send sunlight back into space to cool Earth in secret test

New Delhi:

According to the New York Times, after the earth experienced the hottest year on record in 2023, American scientists tried to reflect some of the sun’s rays back into space as a way to temporarily cool the earth.

They used cloud-brightening technology, which makes clouds brighter so they reflect a small portion of incoming sunlight, lowering the temperature of an area. If successful, the technology aims to place multiple devices over the ocean to reduce rising seawater temperatures.

Secret testing of decommissioned ships

On April 2, researchers at the University of Washington fired a mist of salt particles into the sky at high speed through a snowmaking machine-like device placed on top of a decommissioned aircraft carrier in San Francisco.

The experiment was conducted under a secret project called CAARE (Coastal Atmospheric Aerosol Research and Engagement).

The idea is to use clouds as mirrors to reflect incoming sunlight, a concept explained by British physicist John Latham in 1990. He proposed creating a fleet of 1,000 ships that would sail around the globe spraying seawater droplets into the air to deflect the sun’s heat and absorb it. Reduce the temperature of the earth.

How does it work?

The idea behind the technology is simple science: A large number of small water droplets reflect more sunlight than a small number of large water droplets. Therefore, spraying an aerosol salt mist into the air can be used to reflect sunlight.

But getting the size and number of particles right is crucial. If the particles are too small, they won’t reflect, and particles that are too large will make the cloud less reflective.

For this test, scientists needed particles 1/700th the thickness of a human hair and sprayed 10 million of them every second.

Can it fight global warming?

As countries around the world fall short of the goal of keeping temperatures 1.5 degrees Celsius higher than pre-industrial times, scientists are looking for novel solutions that can produce dramatic results quickly.

While some claim the process could balance global warming caused by increased carbon dioxide, some scientists believe the results of solar modification methods are difficult to predict.

Overuse of the technology could alter climate patterns over time, they say. For example, changes in ocean temperatures can alter marine biology and rainfall patterns, increasing rainfall in one area while decreasing rainfall in another.