One reason is "the level of panic" surrounding greenhouse-gas levels, which are growing at around three per cent a year and are now more than a third greater than before the Industrial Revolution, says Thomas.
Another, he suggests, is "an astonishing switch" by former climate sceptics and conservative lobby groups in the United States. After years of denial or contestation, these powerful forces have now suddenly accepted that global warming is a problem.
They have seized on geo-engineering as a solution that would make it unnecessary to slap costly curbs on big polluters, he argues. The scientific establishment is still far from endorsing geo-engineering, though.
Test plans
Indeed, the UN's Nobel-winning Intergovernmental Panel on Climate Change (IPCC), in its landmark fourth assessment report last year, cautioned of the potential risk and unquantified cost of such schemes.
All the same, geo-engineering is now getting a serious look by scientists and several names are cautiously saying it would be worthwhile to at least launch small-scale experiments to see how they pan out.
This year, Britain's de-facto academy of sciences, the Royal Society, raised eyebrows when one of its journals published geo-engineering papers, which were balanced by a review by a top climatologist, Stephen Schneider of Stanford University.
The Royal Society is carrying out its own analysis of geo-engineering, although it also makes clear that this act is not a sign of its approval. The report will be published in the first half of 2009.
Respectable advocates
In an interview on the sidelines of the U.N. climate in Poznan, IPCC chief Rajendra Pachauri agreed geo-engineering "is getting a closer hearing, and you are getting people who are very respectable advocating it in several cases."
"But the very fact that it's undergoing scrutiny is a good sign, because [it reveals] all the implications and all the side effects that you might be saddled with," he said.
David Santillo, a senior scientist with the Greenpeace Research Laboratories at the University of Exeter, southwestern England, said scrutiny is fine, but it should not be taken as acceptance.
"There is a danger that the more these things get talks about, the more people assume that there is some inherent legitimacy with the proposals that are being put forward. That simply is not the case," said Santillo.
Wacky
IF these large scaled schemes were 100% proof positive without a shadow of doubt feasible AND worked perfectly it still wouldn't be done for one simple reason. It isn't about global warming.
global warming
well, nothing is 100% proof positive, so i say give it a try!!!!!!and it IS about global warming. :-/....... :~)
global warming
well, nothing is 100% proof positive, so i say give it a try!!!!!!and it IS about global warming. :-/....... :~)
global warming
No solve the problem do not try and stick a plaster on the jod and then say "now it's fixed" if the trash (sorry politicians) can't get their ego's together fire them. Surely we've pandered to these scum bags long enough,time to wake up and stop playing games.
Please don't do this
These geo-engineering solutions have credence only when governments lack the political will to use market-based solutions, especially cap-and-trade. Conservation methods can solve the problem far more cheaply and safely than these very risky proposals.
john raffensperger