Guardian: 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 …