The reason that deforestation is harmful to the climate is that when trees are cut they release the carbon they are storing into the atmosphere, where it mixes with greenhouse gases from other sources and contributes to global warming accordingly. The loss of our forests results in a chain reaction, where too much carbon is released into the air, with not enough oxygen to combat it.
Greenhouse gases are those, that absorb and emit infrared radiation in the wavelength range emitted by the earth. The most abundant greenhouse gases in earth's atmosphere are: water vapour (), carbon dioxide (), methane (), nitrous oxide (), ozone (), chlorofluorocarbons (CFCs). These gases absorbs solar energy and increases the earth's temperature. Thus, the correct answer is option A.