how much oxygen is in the earth's atmosphere
Atmosphere of Earth By volume, dry air contains 78.09% nitrogen, 20.95% oxygen,[2] 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air content and atmospheric pressure vary at different layers, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's troposphere and in artificial atmospheres.
Northern Hemisphere Its surface is 60.7% water, compared with 80.9% water in the case of the Southern Hemisphere, and it contains 67.3% of Earth's land.[2]
Carbon dioxide in Earth's atmosphere Over the past 400,000 years, CO2 concentrations have shown several cycles of variation from about 180 parts per million during the deep glaciations of the Holocene and Pleistocene to 280 parts per million during the interglacial periods. Each part per million by volume of CO2 in the atmosphere contains approximately 2.13 gigatonnes of carbon.[10] Currently CO2 constitutes about 0.041% (equal to 410 ppm) by volume of the atmosphere,[11][12] which corresponds to approximately 3200 gigatons of CO2, which includes approximately 870 gigatons of carbon. The global mean CO2 concentration is currently rising at a rate of approximately 2 ppm/year and accelerating.[13][14]
Paris Peace Accords