Experts are hoping to use an ingenious technique known as stratospheric aerosol injection (SAI) which could reduce the rate of global warming by up to 50 percent. The proposal would see scientists inject the stratosphere – a part of Earth’s atmosphere which is about 20 kilometres above the surface – with reflective sulphites which reflect sunlight back into the cosmos. If successful, it would prevent solar energy from adding to the heating globe which will eventually reduce climate change.
The project, if it is launched, could take up to 15 years to complete.
Dr Gernot Wagner, from Harvard University‘s School of Engineering and Applied Sciences, and co-author of the study published in Environmental Research Letters: “Given the potential benefits of halving average projected increases in radiative forcing from a particular date onward, these numbers invoke the ‘incredible economics’ of solar geoengineering.
“Dozens of countries could fund such a program, and the required technology is not particularly exotic.”
To get the sulphites into the atmosphere, researchers from Harvard and Yale universities propose using a high-altitude aircraft, balloons or large naval-style guns.
Co-author Wake Smith, a lecturer at Yale College, who was formerly president of the flight training division of Boeing, said: “I became intrigued by the engineering questions around SAI and the many studies that purport to show that modified existing planes could do the job. Turns out that is not so.
“It would indeed take an entirely new plane design to do SAI under reasonable albeit entirely hypothetical parameters.
“No existing aircraft has the combination of altitude and payload capabilities required.”
“We developed the specifications for SAI with direct input from several aerospace and engine companies. It’s equivalent in weight to a large narrow body passenger aircraft.
“But to sustain level flight at 20 kms, it needs roughly double the wing area of an equivalently sized airliner, and double the thrust, with four engines instead of two.
“At the same time, its fuselage would be stubby and narrow, sized to accommodate a heavy but dense mass of molten sulphur rather than the large volume of space and air required for passengers.”
However, the researchers state this is purely hypothetical for the time being.
Dr Wagner added: “It would also be remarkably inexpensive.”
“Solar geoengineering is often described as ‘fast, cheap, and imperfect’.
“While we don’t make any judgement about the desirability of SAI, we do show that a hypothetical deployment program starting 15 years from now, while both highly uncertain and ambitious, would be technically possible strictly from an engineering perspective.
“It would also be remarkably inexpensive, at an average of around $2bn – $2.5bn (£1.5bn – £1.9bn) per year over the first 15 years.”