(CNN) – Scientists suggest an ingenious, yet unprotected way to tackle climate change: spraying chemicals by dimming the sun into the Earth's atmosphere.
A study by scientists at Harvard and Yale University, published in the Environmental Research Letters, suggests using a technique known as a stratospheric aerosol injection (SAI), which they say could reduce the global warming rate in half.
The technique will involve spraying large amounts of sulphate particles into the lower stratosphere of the Earth at an altitude of up to 12 miles. Scientists suggest the delivery of sulphates with specially designed high-risk aircraft, balloons or large sea pistols.
Although technology has not yet been developed and no existing aircraft currently fit for adjustment, the researchers say "the development of a new, purpose-built tanker with significant load options will not be technologically difficult or too expensive."
They estimate the total cost of opening a hypothetical SAI system for 15 years to about $ 3.5 billion, with ongoing costs of $ 2.25 billion a year over a period of 15 years.
The report, however, acknowledges that the technique is purely hypothetical right now.
"We do not make a ruling on the desirability of an SAI," the report said. "Simply show that the hypothetical deployment program, which starts from 15 years, hence both, and very uncertain and ambitious, would really be technically possible from an engineering perspective. It will also be incredibly cheap."
They also recognize potential risks – co-ordination between several countries in both hemispheres will be needed, and SAI techniques could endanger crop yields, lead to drought, or cause extreme weather.
The proposals also do not address the issue of increasing greenhouse gas emissions, which are the leading cause of global warming.
Despite the conviction of the lead authors of the report, some other experts were skeptical.
"From the aspect of the climate economy, the management of solar radiation is still a much worse solution than greenhouse gas emissions: more expensive and much more risky over the long term," said Philip Talman of the Lausanne Ecotech Polytechnic Federal Court, an expert in the climate change climate , said CNN.