A Blog about Climate Change, the Environment and Sustainability

By 2050 or so, the world population is expected to reach nine billion, essentially adding two Chinas to the number of people alive today. Those billions will be seeking food, water and other resources on a planet where, scientists say, humans are already shaping climate and the web of life. In Dot Earth, a New York Times blog, reporter Andrew C. Revkin examines efforts to balance human affairs with the planet's limits.