From the New York Times:
Climate change is already having sweeping effects on every continent and throughout the world’s oceans, scientists reported Monday, and they warned that the problem is likely to grow substantially worse unless greenhouse emissions are brought under control.
The report by the Intergovernmental Panel on Climate Change, a United Nations group that periodically summarizes climate science, concluded that ice caps are melting, sea ice in the Arctic is collapsing, water supplies are coming under stress, heat waves and heavy rains are intensifying, coral reefs are dying, and fish and many other creatures are migrating toward the poles or in some cases going extinct.
The oceans are rising at a pace that threatens coastal communities and are becoming more acidic as they absorb some of the carbon dioxide given off by cars and power plants, which is killing some creatures or stunting their growth, the report found.
Organic matter frozen in Arctic soils since before civilization began is now melting, allowing it to decay into greenhouse gases that will cause further warming, the scientists said.
And the worst is yet to come, the scientists said in the second of three reports that are expected to carry considerable weight next year as nations try to agree on a new global climate treaty. In particular, the report emphasized that the world’s food supply is at considerable risk — a threat that could have serious consequences for the poorest nations.
…The experts did find a bright spot, however. Since the group issued its report in 2007, it has found growing evidence that governments and businesses around the world are starting extensive plans to adapt to climate disruptions, even as some conservatives in the United States and a small number of scientists continue to deny that a problem exists.