Spraying aerosols at sky to block sunshine ‘could HALT global warming’, experts admit
The plan would require the construction of entirely new kinds of aircraft and would cost around $2 billion a year to run, although the authors focus more on the practicalities of the plan than on whether it would be desirable
A PLAN to halt man-made global warming by spraying aerosols into the atmosphere "is possible," according to a new study published today.
The plan would require the construction of an entirely new kind of aircraft and would cost at least $2 billion a year, but the study's authors affirm that it would be "technically possible strictly from an engineering perspective."
Publishing in Environmental Research Letters, the new study set out to examine the practicalities and costs of what is called "stratospheric aerosol injection" (SAI).
Simply put, this would involve injecting molten sulphur into the lower stratosphere (about 20km above the Earth's surface), which in theory would block sunlight and reduce the extent to which the Earth captures heat.
The would in turn reduce global warming, and given that the project would cost between $2 billion and $2.5 billion a year to fund, the authors conclude that it is desirable from a purely cost-effectiveness standpoint.
"Given the potential benefits of halving average projected increases in radiative forcing [heat capture] from a particular date onward, these numbers invoke the 'incredible economics' of solar geoengineering," said co-author Dr Gernot Wagner, of Harvard University.
However, while the study shows that such a plan is technically feasible, it comes with a few difficulties.
For one, it would require the invention and construction of a new kind of airplane, since current models aren't currently up to the challenge.
"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," said Yale College's Wake Smith.
"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."
Another issue is that the authors seem to be suggesting that, while the world's governments could certainly afford to regularly drop sulphur out of high-altitude planes, this might not actually halt global warming to a significant extent.
As Gernot Wagner says, "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" (the Sun's emphasis).
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These qualifications indicate that the authors aren't entirely sure if the plan they describe would reduce climate change; instead, they seem to be focusing mostly on the physical possibility of launching aircraft into the stratosphere and dropping aerosols into the sky.
That said, an October from the Intergovernmental Panel on Climate Change (IPCC) did conclude that geoengineering could be effective in limiting temperature rises to only 1.5 C.
However, it also noted that geoengineering may have unwanted side-effects on the Earth's environment and ecosystems.
Do you think this plan could reduce global warming? Let us know in the comments.
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