(CNN) – Scientists are proposing a clever but unproven way to deal with climate change: spraying the sun's dimming chemicals into the Earth's atmosphere.
Research by scientists at Harvard and Yale University, published in the journal Environmental Research Letters, proposes using a technique known as stratospheric aerosol injection (SAI), which they say could reduce the rate of global warming by half.
This technique will involve spraying large amounts of sulfate particles into the Earth's lower stratosphere at a height of 12 miles. Scientists propose sulfate shipments with specially designed high-flying aircraft, large balloons or naval weapons.
Although undeveloped technology and no aircraft currently available is suitable for adaptation, the researchers say "developing new-purpose, built-in tankers with large payload capabilities will not be technically difficult or expensive."
They estimate the total cost of launching a hypothetical SAI system in 15 years to around $ 3.5 billion, with an operational cost of $ 2.25 billion per year over a 15-year period.
However, the report acknowledges that this technique is purely hypothetical now.
"We did not make an assessment of the wishes of SAI," said the report. "We only point out that a hypothetical deployment program that began 15 years later, while both were very uncertain and ambitious, would be technically possible from an engineering perspective. It's also very cheap. "
They also recognize the potential risks – coordination between several countries in both hemispheres will be needed, and the SAI technique can endanger crop yields, cause drought or cause extreme weather.
The proposal also does not address the issue of increasing greenhouse gas emissions, which are a major cause of global warming.
And regardless of the report's main author's beliefs, some other experts were skeptical.
"From a climate economics point of view, management of solar radiation is still a far worse solution than greenhouse gas emissions: more expensive and far more risky in the long term," Philippe Thalmann of the École Polytechnique Fédérale de Lausanne, an expert in the climate change economy, told CNN.