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Boffins: Give up on CO2 cuts, only geoengineering can work

Ordinary eco-efforts a foolish distraction

Bitchslap for white roofs and artificial trees

The pair seem to back up the worst fears of conventional climate scientists, by saying - more or less - that it would be cheaper for the human race to carry on emitting carbon as much as we like and save the planet using geoengineering, as compared to cutting CO2 emissions. A renewables or nuclear powered world using electric or hydrogen transport would be much more expensive to implement than a coal and oil burning civilisation with global warming controlled by an upper-atmosphere particulate sunscreen, for instance.

While some approaches, such as ocean fertilization or white-roof techniques, can be ruled out because they are unlikely to have a significant global climate benefit, most of the geoengineering proposals appear cheap compared with conventional mitigation. More importantly, many have a higher climate benefit to annual cost ratio than conventional mitigation...

The estimated costs of maintaining a sulphate aerosol shield, most likely through a small number of dedicated high-flying aircraft, are remarkably cheap compared with the costs of conventional mitigation by factors of hundreds or even thousands.

The Institution of Mechanical Engineers will be cross, as they have recently suggested that white roofs would be a good notion. In the same document, the IMechE also said that extraction of CO2 from the atmosphere for sequestration underground would be a brilliant plan.

Cox and Jeffery disagree, however, saying that artificial trees and sequestration would be even more expensive than cutting emissions. The only advantage of the scheme would be that it probably couldn't have unforeseen negative side-effects as with the upper-atmos particulate planes notion. But one could say the same of cutting emissions, which would be cheaper than artificial trees - and yet still so expensive as to mean that it can't happen.

The safest alternative to conventional mitigation is CO2 air capture, which removes the primary cause of global warming and therefore avoids the risks associated with termination, regional climate change and ocean acidification. Currently, however, air capture appears expensive relative to conventional mitigation and very expensive relative to large-scale techniques for solar-radiation management.

Essentially, according to the two boffins, the only planet-saving plans the human race is likely to actually carry out are those which are significantly cheaper and more convenient than conventional emissions cuts. Such plans would appear to offer the only realistic way that a very serious temperature rise can be avoided: so in fact, they should be the main stream of climate science - rather than on the fringe as they are now.

"For scientists who want to save the planet, there should be no more attractive research field than geoengineering," the pair write. ®

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