ABSTRACT
This chapter begins with the ecology of the atmosphere and considers how we should respond to air pollution and the increase in greenhouse gases (GHGs). Then authors consider the water cycle and confront the problems of water pollution and the scarcity of clean water. In the biosphere, air and water intermingle almost everywhere. The atmosphere contains water particles, and water in the oceans, lakes, and streams absorbs the gases of the atmosphere. Air and water are only "polluted" by the presence of these substances when the concentration is too high. Too much sulfuric acid in the atmosphere causes "acid rain," which kills plants, and too much ground-level ozone harms plants and animals. Water vapor and other natural gases in the atmosphere act like a glass ceiling, letting the light through and blocking much of the heat radiating from the earth. This is known as the greenhouse effect, because this process is how glass warms a greenhouse.
