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
Reducing atmosphere billion years of age—was comparable to that of present-day lava. This observation implies that Hadean atmospheric oxygen levels were similar to those of today. The results do not, however, run contrary to existing theories on life’s journey from anaerobic to aerobic organisms. The results quantify the nature of gas molecules containing carbon, hydrogen, and sulphur in the earliest atmosphere, but they shed no light on the much later rise of free oxygen in the air. Although a hard vacuum, interplanetary space is reducing, because solar wind consists mostly of hydrogen plasma. The Moon is directly exposed to solar wind, such