Cogeneration of electricity and heat is one of the most promising means of using existing technologies for sustainable ends, but it is also one of the most neglected and least understood. Cogeneration can dramatically increase energy efficiency, slash carbon emissions, and save money.

In the world of alternative fuels, there may be nothing greener than pond scum.

Algae are tiny biological factories that use photosynthesis to transform carbon dioxide and sunlight into energy so efficiently that they can double their weight several times a day.

When you hear the word "NASA," do visions of rocket ships dance in your head?

Well think again. From now on, it's "earthworms."

WWF Director-General James Leape today called on governments to support the entry into force of the 1997 UN Watercourses Convention—an international agreement which could play a key role in water security for about 40% of the world's population.

Diana Khidasheli and her four children spent the night before the August 8 outbreak of war with Russia in their house basement, hoping for an end to the intensive shelling of their village, Kemerti, in the Georgian-controlled South Ossetia conflict zone. Now Khidasheli thinks the decision to hide was a mistake. The next day, she had no time to pack.