1. Greenhouse gases and global warming

The greenhouse effect is created by a difference in the way the Earth's atmosphere reacts to electromagnetic heat waves. A distinction must be made between short-wave radiation (CLO), i.e. ultraviolet and visible waves, and long-wave radiation (GLO), mainly infrared. Opaque bodies emit GLO-type heat waves, and generally absorb a large proportion of CLO and GLO waves. On the other hand, some gases and transparent solids allow a large proportion of GLO waves to pass through without absorbing them, but do absorb GLO waves.

The sun mainly emits GLO waves, a large proportion of which pass through the earth's atmosphere and are absorbed by the earth's surface (absorptivity around 90%). The earth, for its part, emits infra-red heat waves, depending on its temperature, which are largely absorbed by the earth's atmosphere, which in turn emits GLO waves towards the earth...