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
Runaway greenhouse effect feedback effect from increased atmospheric water vapor, as well as Earth being too far away from the Sun at its current luminosity for such to occur is well below that which is required to boil away the oceans. Climate scientist John Houghton has written that "[there] is no possibility of [Venus's] runaway greenhouse conditions occurring on the Earth". However, climatologist James Hansen disagrees. In his "Storms of My Grandchildren" he says that burning coal and mining shale oil will result in runaway greenhouse on Earth. A re-evaluation in 2013 of the effect of water vapor in the climate models showed