The global motor vehicle population has grown very rapidly in the past half century and is expected to continue to grow rapidly for the next several decades, especially in developing countries. As a result, vehicles are a major source of urban air pollution in many cities and are the fastest-growing source of greenhouse emissions. Strategies exist to reduce both problems, but many countries emphasize one over the other rather than pursuing strategies that reduce both concerns.

Next week, government negotiators will gather in Bangkok, Thailand, for the latest round of international climate change talks.

Could biofuels do more damage to the climate than the fossil fuels they replace?

As the energy industry hungrily eyes methane hydrates, scientists ponder the fuel's impact on climate.

Renewable energy will contribute 10% of China's energy consumption by 2010, forecasts the country's latest 5-year plan.