It all seemed too easy by half: to beat global warming just sprinkle some iron in the ocean, then watch as algae bloom en masse, sucking up carbon dioxide by the tonne. Now the idea is looking increasingly unlikely to go ahead in a big way. In the wake of a UN moratorium on the practice, the latest research suggests that seeding will trigger the build-up of an acid that can be lethal to marine organisms and humans.

Climate change is the biggest science issue in the world, and the biggest science issue in the upcoming US election. Who is the front runner? If you look at the parties, it's a no-brainer: the Democrats snatched control of both houses of Congress in 2006, and have so far made good on their promises to fight climate change. Feb 27, 2008