(CNN) – Scientists are proposing an ingenious, but not yet proven, way of combating climate change: to pulverize chemicals that cause the sun into the Earth's atmosphere.
Researchers at Harvard and Yale universities, published in the journal Environmental Research Letters, suggest using a technique known as Stratospheric Aerosol Injection (SAI), which they say 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 yet developed and no existing aircraft are currently suitable for adaptation, researchers say that "developing a new specific purpose tanker with substantial payload capabilities would not be technologically difficult nor prohibitively expensive."
They estimate the total cost of launching a hypothetical UPS system over 15 years, at around $ 3.5 billion, with operating costs of $ 2.25 billion per year over a 15-year period.
The report, however, acknowledges that the technique is purely hypothetical now.
"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. "
They also recognize the potential risks – coordination between several countries in both hemispheres would be necessary, and IAS 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 main authors' conviction, some 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 term," says Philippe Thalmann of the École Polytechnique Fédérale de Lausanne. economics of climate change, he told CNN.