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.
Global warming is caused by a phenomenon known as the greenhouse effect. A greenhouse (or glasshouse) is good for growing things because it traps heat inside and stays hotter than the atmosphere around it.t's not really warming up noticeablyâat least not in the short term. In fact, since 1900, the whole planet has warmed up only by around 0.8 degrees Celsius. By the end of the 21st century, however, global warming is likely to cause an increase in Earth's temperature of around 2â5 degrees Celsius.