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
Anti-greenhouse effect trapping infrared radiation generated by the surface. Although a large greenhouse effect does keep Titan at a much higher temperature than the thermal equilibrium, the anti-greenhouse effect due to the haze reduces the surface temperature by 9 K. Because greenhouse effect due to other atmospheric components increase it by 21 K, the net effect is that the real surface temperature of Titan (94 K) is 12 K warmer than the effective temperature 82 K (which would be the surface temperature in the absence of any atmosphere, assuming constant albedo). Anti-greenhouse effect The anti-greenhouse effect is a mechanism similar to the