Greenhouse gas Greenhouse gas A greenhouse gas is a gas that absorbs and emits radiant energy within the thermal infrared range. Greenhouse gases cause the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide and ozone. Without greenhouse gases, the average temperature of Earth's surface would be about , rather than the present average of . The atmospheres of Venus, Mars and Titan also contain greenhouse gases. Human activities since the beginning of the Industrial Revolution (around 1750) have produced a 40% increase in the atmospheric concentration of carbon dioxide (), from 280 ppm
What on Earth! habits and funeral rites of this "species." The film shows the earth from the view of the Martian flying machines which did not land but used cameras to film earth society. It then follows one average (what it believes to be) earthling and its civilization, by in effect showing a "day in the life" and how they live it. First, it shows one going through dinner with a precisely regulated feeding (vehicle refueling from a gas pump), then it must take its rest (pulling into an attached garage next to a house), because it will have a busy day the