Geo-engineering is increasingly looking like the only politically viable way of averting temperature rises above 2 degrees in the coming century. This is for three interlocking reasons: i) Any mayor country can try geo-engineering on its own without permission from anyone else, meaning one does not need a world coalition sustained for centuries to have an effect; ii) It holds the promise of immediate relief because ‘natural Solar Radiation Management’, ie volcanic eruptions that add lots of light-reflecting particles into the atmosphere, were found to cause immediate worldwide temperature drops, which compares favourably with the lags of decades and centuries that hold for CO2 emission reduction plans; and iii) It might be exceedingly cheap compared to any policy involving emission markets. For instance, according to a 2012 piece by McClellan and co-authors, we could keep the planet at current temperature levels at a cost of merely 10 billion dollars a year by having a fleet of planes deliver reflective particles high in the earth’s atmosphere.
Given that continued global warming is predicted to happen in the next century no matter what emission policies are adopted, geo-engineering by some impatient large country is starting to look nigh inevitable. I reported in 2012 on the research efforts funded by the Royal Society, the Gates Foundation, and others. You now have dedicated institutes on this issue (eg. http://iagp.ac.uk ), and lots of new proposed experiments. With a large glut of published studies in recent years, it is time for an update: how far are we now in the world of geo-engineering?
The honest answer is that the scientific community is pussyfooting around when it comes to geo-engineering. Field experiments are largely stalled as scientists are awaiting regulatory frameworks that will protect them from criticisms of other scientists and environmental groups. Proposed regulatory frameworks designed to deliver this, such as by Nordhaus and colleagues, find it hard to get much political traction because politicians seen to support regulatory frameworks themselves become targets for criticism, both by those who pretend there is no climate change and by those who insist there is climate change but who also insist on emission reductions as the only way to return to our current climate some 300 years from now. Voters who agree the world is getting too hot and who would like it cooled down in their own lifetime rather than that of their great-great-great-great-grandchildren are still too rare to bother with for politicians.
This does not mean there is a lack of bright ideas. The engineers looking into this really are a very creative bunch, talking about whitening clouds, aerosol sprays, reflective shields, and artificial trees. One new idea that I hadn’t heard before is to genetically alter our crops so that they reflect sunlight better than the current crops. I don’t know whether this has any chance of getting serious traction, but one has to admire the ingenuity of the idea. Still, ominously, almost no field tests or large scale long-term testing is underway as scientists are waiting for societal approval to go ahead. Continue reading