WHEN it comes to global warming, extreme scare stories abound. Al Gore, for example, famously claimed that a whopping six metres (20 feet) of sea-level rise would flood major cities around the world. Gore’s scientific advisor, Jim Hansen from NASA, has even topped his protégé. Hansen suggests that there will eventually be sea-level rises of 24 metres (80 feet), with a six-metre rise happening just this century. Little wonder that fellow environmentalist Bill McKibben states that “we are engaging in a reckless drive — by drowning of much of the rest of the planet and much of the rest of...