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
Atmosphere of Venus Venusian thermosphere is the coldest place on Venus with temperature as low as 100 K (−173 °C). It is even called a cryosphere. The circulation patterns in the upper mesosphere and thermosphere of Venus are completely different from those in the lower atmosphere. At altitudes 90–150 km the Venusian air moves from the dayside to nightside of the planet, with upwelling over sunlit hemisphere and downwelling over dark hemisphere. The downwelling over the nightside causes adiabatic heating of the air, which forms a warm layer in the nightside mesosphere at the altitudes 90–120 km. The temperature of this layer—230 K