Interviewed last week, John Holdren, President Obama's chief scientific adviser, said that drastic measures should not be "off the table" in discussions on how best to tackle climate change and that geo-engineering could not be ruled out. Making clear these were his personal views, he said: "It's got to be looked at. We don't have the luxury of taking any approach off the table."
He's right. We don't have that luxury – not only because the Kyoto protocol's first phase, running to 2012, is manifestly failing, but because the emissions reduction approach that it embodies cannot succeed. It is manifestly failing because emissions are going ahead faster than even the worst scenarios considered by the IPCC, which provides scientific assessments to the UN Climate Convention and because many rich countries are on course to fall short of their emissions reductions commitments.
Research since the IPCC's last assessment reveals that the threat of climatic disaster ...