Weather changes all the time. The average pattern of weather, called climate, usually stays pretty much the same for centuries if it is left to itself. However, the earth is not being left alone. People are taking actions that can change the earth and its climate in significant ways. Carbon dioxide is the main culprit. The single human activity that is most likely to have a large impact on the climate is the burning of "…showed first 75 words of 839 total…

…showed last 75 words of 839 total…developed country output is predicted to rise between 4 and 14% and developing country output to fall by 9 to 12%. World food prices go up. The number of people at risk of hunger (due to higher prices) probably also goes up, perhaps by 50%. This analysis assumed that no major changes, such as construction of new irrigation projects, are undertaken. If such changes are included, the agricultural impact on all but the poorest developing countries probably becomes very small