The world leaders who met at the United Nations to discuss climate change on Tuesday are faced with an intricate challenge: building momentum for an international climate treaty at a time when global temperatures have been relatively stable for a decade and may even drop in the next few years.

As oil and gas companies press to tap new deposits in remote places, scientists are trying to gauge and limit the ecological impact of pipes and other structures in otherwise wild lands.

Twenty-five years after the federal government declared a long stretch of the Hudson River to be a contaminated Superfund site, the cleanup of its chief remaining source of pollution began here Friday with a single scoop of mud extracted by a computer-guided dredge.

A new analysis halves longstanding projections of how much sea levels could rise if Antarctica

For more than a decade the Global Climate Coalition, a group representing industries with profits tied to fossil fuels, led an aggressive lobbying and public relations campaign against the idea that emissions of heat-trapping gases could lead to global warming.

After decades of false starts, Afghanistan is creating its first national park, Band-e-Amir, encompassing a sprawling swath of rugged land surrounding a series of deep blue lakes in the mountains west of Kabul. The lakes sit behind natural travertine dams.

For at least 3,000 years, a drumbeat of potent droughts, far longer and more severe than any experienced recently, have seared a belt of sub-Saharan Africa that is now home to tens of millions of the world

Evidence from fossil coral reefs in Mexico underlines the potential for a sudden jump in sea levels because of global warming, scientists report in a new study.

The study, being published Thursday in the journal Nature, suggests that a sudden rise of 6.5 feet to 10 feet occurred within a span of 50 to 100 years about 121,000 years ago, at the end of the last warm interval between ice ages.

Five countries that created a treaty nearly four decades ago to protect polar bears through controlled hunting issued a statement that called climate change "the most important long-term threat" to the bears.

The annual summer retreat of the sea ice cloaking the Arctic Ocean appears to have ended with the ice not quite matching last year's extraordinary recession, polar scientists said.