POLLUTION

This coal-fired power plant in Macedonia, seen on Dec. 10 as pigs feed on a nearby trash dump, is one of thousands around the world that emit large quantities of carbon dioxide.

Thick smoke from a coal-fired oven fills the air in this neighborhood of Calcutta, India, on Dec. 9. Coal burning is a key source of manmade carbon dioxide emissions.

Iceberg B17B, top left, floats in the Ross Sea near Antarctica after it broke off from the Ross Ice Shelf nearly 10 years ago. The monster iceberg, at 12 miles long and 5 miles wide nearly twice the size of Hong Kong, has been slowly drifting toward Australia in what scientists call a once-in-a-century event. It is now about 1,100 miles southwest of Australia. Accelerated glacial and ice shelf melt and collapses have been tied to global warming.

A man walks through heaps of ash outside a thermal power plant in the village of Doburjian in the northern Indian state of Punjab on Dec. 9. A 20 percent cut in greenhouse gases by rich nations would be a "pretty good" result for a U.N. climate summit, even though it falls short of developing nations' hopes, the head of the U.N. climate panel said during the meeting’s opening days.

Garbage is scattered across a ship repair yard in Mumbai, India, on Dec. 3. Rising seas is one issue before the climate conference in Copenhagen.