Weather warning
Britain's Chief Scientist told an American audience in Seattle how dangerous he believes global warming to be.
We already know he thinks it's a more serious threat to national security than al-Qaeda. Now strategic planners working for the Pentagon have produced their own report on the risk climate change poses to global stability.
Growing evidence suggests the planet is being pushed to a tipping point that could alter the weather radically, not in centuries - but in a decade. If that happens it could cause mayhem in countries overwhelmed and destabilised by huge temperature shifts.
Ben Geoghegan reported.