Atmosphere of Earth development of animals. Today's atmosphere contains 21% oxygen, which is great enough for this rapid development of animals. "Air pollution" is the introduction into the atmosphere of chemicals, particulate matter or biological materials that cause harm or discomfort to organisms. Stratospheric ozone depletion is caused by air pollution, chiefly from chlorofluorocarbons and other ozone-depleting substances. The scientific consensus is that the anthropogenic greenhouse gases currently accumulating in the atmosphere are the main cause of global warming. On October 19, 2015 NASA started a website containing daily images of the full sunlit side of Earth on http://epic.gsfc.nasa.gov/. The images are taken
Climate of Titan However the methane in the atmosphere causes a substantial greenhouse effect which keeps the surface of Titan at a much higher temperature than what would otherwise be the thermal equilibrium. Haze in Titan's atmosphere contributes to an anti-greenhouse effect by reflecting sunlight back into space, making its surface significantly colder than its upper atmosphere. This partially compensates for the greenhouse warming, and keeps the surface somewhat cooler than would otherwise be expected from the greenhouse effect alone. According to McKay et al., "the anti-greenhouse effect on Titan reduces the surface temperature by 9 K whereas the greenhouse effect increases it