global warming and air-conditioner

http://environment.nationalgeographic.com/environment/green-guide/buying-guide/air-conditioner/environmental-impact/

In burning fossil fuels such as coal to supply electricity to homes and workplaces, power plants discharge clouds of soot and other pollutants into the atmosphere. Among these are mercury and carbon dioxide (CO2). Air conditioner use in the U.S. results in an average of about 100 million tons of CO2 emissions from power plants every year.