Drilling shale to capture oil and gas is a technology that China, which burns a lot of coal, is eager to learn. That's why it's a partner in a south Texas 'fracking' project.
If humans heated the earth, perhaps our technology can cool it, too. A look at the science of geoengineering and how it might be used to address global warming.
Yvo de Boer, executive secretary of the United Nations Framework Convention on Climate Change (UNFCCC), steps down, effective July 1.
UN officials say it gave fresh momentum to upcoming talks for a new climate change treaty. But many unresolved issues remain.