: The main idea of paragraph 9 is Although air-conditioning has led to economic improvement and has increased daily comfort for people everywhere, its impact on the emvironment has not been so positive According to experts, global warming could result in dramatic changes in climate, rising oceans levels, and more violent storms in the years to come The burning of coal and oil to produce this energy also contributes to air pollution and thus to global warming (C) Furthermore, running air-conditioning on a large scale requires enormous amounts of energy