Earth's getting warmer

Crossing this threshold, the earth will face many environmental disasters, according to the Intergovernmental Panel on Climate Change report released last night.

The committee, made up of 100 prominent scientists from the United Nations, said that to keep global temperatures from rise so high, CO2 emissions must be reduced to zero by 2050. Renewable energy must account for 85% of global electricity. Coal consumption must fall to almost 0%. The world needs to use up to 7 million square kilometers of land to grow crops for biofuel production.

This is believed to be technically feasible but politically difficult, especially for industrial economies emitting much of the greenhouse gas.