Scientists are proposing an ingenious, but not yet proven, way of combating climate change: pulverizing chemicals that cause the sun to sink into Earth's atmosphere.
CNN reports that research by scientists at Harvard and Yale universities, published in the journal Environmental Research Letters, proposes the use of a technique known as stratospheric aerosol injection, which it claims would reduce the global warming rate by half.
The technique would involve spraying large amounts of sulfate particles in the Earth's lower stratosphere at altitudes of up to 12 miles. Scientists propose the delivery of sulfates with specially designed high-altitude aircraft, balloons or large naval guns.
Although the technology is not developed and there are no existing aircraft suitable for adaptation, the researchers say that "developing a new specific purpose tanker with substantial payload capabilities would not be technologically difficult or prohibitively expensive."
They estimate the total cost of launching a hypothetical system in 15 years by about $ 3.5 billion, with operating costs of $ 2.25 billion per year over a 15-year period.
The report recognizes, however, that the technique is purely hypothetical.
"We do not make judgments about the suitability of SAI," the report says. "We have simply shown that a hypothetical deployment program starting 15 years from now, although highly uncertain and ambitious, would in fact be technically possible from an engineering point of view. It would also be incredibly cheap. "
Researchers also recognize the potential risks: coordination between multiple countries in both hemispheres would be necessary, and stratospheric aerosol injection techniques could hamper crop yields, lead to droughts or cause extreme weather conditions.
The proposals also do not address the issue of rising greenhouse gas emissions, which are a major cause of global warming.
And despite the authors' conviction, other experts were skeptical.
"From the point of view of climate economics, the management of solar radiation is still a far worse solution than greenhouse gas emissions: more expensive and much more risky in the long run," said Philippe Thalmann of the École Polytechnique Fédérale de Lausanne. the economics of climate change.
David Archer, of the Department of Geophysical Sciences at the University of Chicago, said, "The problem with the engineering climate is that it is only a temporary band-aid covering a problem that will persist for essentially forever, in fact hundreds of thousands of years for fossils. CO2 fuel to finally disappear naturally.
"It will be tempting to continue to procrastinate the cleansing of our energy system, but we will be leaving the planet in a form of life support. If a future generation failed to pay their climate bill, they would get all our warming up at once. "