Scientists are proposing an ingenious but as-yet-unproven way to tackle climate change: spraying sun-dimming chemicals into the Earth’s atmosphere. From a report: A fleet of 100 planes making 4,000 worldwide missions per year could help save the world from climate change. Also, it may be relatively cheap. That’s the conclusion of a new peer-reviewed study in Environmental Research Letters. It’s the stuff of science fiction. Planes spraying tiny sulphate particulates into the lower stratosphere, around 60,000 feet up. The idea is to help shield the Earth from just enough sunlight to help keep temperatures low. The researchers examined how practical and costly a hypothetical solar geoengineering project would be beginning 15 years from now. The aim would be to half the temperature increase caused by heat-trapping greenhouse gases. This method would mimic what large volcanoes do. In 1991, Mount Pinatubo erupted in the Philippines. It was the second largest eruption of the 20th century, according to the United States Geological Survey (USGS). In total, the eruption injected 20 million tons of sulfur dioxide aerosols into the stratosphere. USGS said the Earth’s lower atmosphere temperature dropped by approximately 1-degree Fahrenheit. The effect only lasted a couple of years because the sulfates eventually fell to Earth.
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