Much attention has been paid to how global warming is affecting the world’s polar regions and glaciers. But a leading authority on tropical forests warns that rising temperatures could have an equally profound impact on rainforests and are already taking a toll on some tropical species.

Now in its seventh year, the EU’s carbon emissions trading system is the only international program designed to use market mechanisms to control CO2 emissions. But critics contend it has done little to slow the release of CO2 and argue that it should be significantly reformed — or scrapped.

Across the U.S., companies are planning scores of projects to burn trees and wood waste to produce electricity, claiming such biomass plants can be carbon-neutral. But critics contend that combusting wood is not really a form of green energy and are urging a go-slow approach until clear guidelines can be established.

Among the many measures the world can take to wean itself off fossil fuels, few match the benefits of making homes, business, and cars more energy-efficient. But financial and psychological barriers have kept individuals, businesses, and governments from realizing efficiency’s great potential.

One of the many casualties of the recent U.S. elections was Congressman Rick Boucher, a Virginia Democrat who played a key role in passage of cap-and-trade legislation by the House of Representatives. In an interview with Yale Environment 360, Boucher discusses the bitter failure of the Senate to pass a climate bill and future prospects for tackling global warming.

To offset their own carbon emissions, European companies have been overpaying China to incinerate a powerful greenhouse gas known as hfc 23. And in a bizarre twist, those payments have spurred the manufacture of a harmful refrigerant that is being smuggled into the U.S. and used illegally.

It is a difficult idea to fathom. But the science is clear: Unless we change the way we live, the Earth's coral reefs will be utterly destroyed within our children's lifetimes.

In China, millions of tons of waste from livestock farms are causing severe water pollution and massive emissions of methane. Now, some large livestock operators are turning to biogas fuel production in hopes of creating “ecological” factory farms.

The sludge spill in Hungary dominated world news for days, as horrific images of red-mud rivers appeared nonstop on the Internet, newspaper front pages, and TV screens. Yet other environmental threats — less visible, but potentially more devastating — often go largely unnoticed.

Energy companies are rushing to develop unconventional sources of oil and gas trapped in carbon-rich shales and sands throughout the western United States and Canada. So far, government officials have shown little concern for the environmental consequences of this new fossil-fuel development boom.

As climate scientists wrestle with the complexities of how the planet will react to rising greenhouse-gas levels, no variable is more difficult to decipher than the impact of clouds. But thanks to new satellite data and other technologies, clues are emerging that may help solve the puzzle.