Earth's Climate Is Unbalanced

The world’s largest society of earth scientists, the American Geophysical Union, is warning that human beings have knocked the climate out of balance and that nations will need to sharply cut carbon-dioxide emissions to avoid widespread problems like melting the Greenland ice cap. In a position statement issued today, the society laid out the evidence that recent changes in climate are attributable to human activity. The organization, which has a membership of 50,000, stated that the world would need to cut emissions of greenhouse gases by more than 50 percent to avoid warming the planet by 2 degrees Celsius, a level at which substantial disruptions would take place, it said.