Atmospheric carbon dioxide is the primary source of carbon in life on Earth and its concentration in Earth's pre-industrial atmosphere since late in the Precambrian was regulated by photosynthetic organisms and geological phenomena.
At about 55 km, the mesosphere begins. In the mesosphere, the temperature decreases with height again, because there is very little ozone to warm up the air. Finally, the mesopause divides the mesosphere from the thermosphere, which is the section of the atmosphere higher than 90 km. In this region, the temperature increases again. This time, it is molecular oxygen (O2) that causes the temperature increase.
In the stratosphere, the temperature increases with increasing altitude as the amount of ozone-absorbing ultraviolet rays increases. In the mesosphere, temperatures decrease as altitude increases and can reach -194 degrees Fahrenheit. By contrast, temperatures in the thermosphere can reach over 2,700 degrees Fahrenheit. Learn more about Atmosphere