Weather patterns have an important effect on the distribution of pollutants in the air, on land, and in our oceans. Environmental firms, as well as government agencies such as the Environmental Protection Agency, hire meteorologists to help them predict the environmental impact of construction projects such as power plants and factories. An understanding of prevailing winds near a proposed coal-burning plant, for instance, will help people understand how potential air pollution, acid rain, and ozone levels will impact the environment not only locally but also, perhaps, across many states or even countries.