I would like to devote this thread to discussing the science behind the conclusion that the emission of greenhouse gases by man has lead to global warming.
The main evidence supporting the claim above:-
1. Greenhouse gases maintain the atmosphere near the Earth's surface at level of about 33 degrees warmer than would be expected from simple radiation calculations.
2. The globe has warmed over the last 100 years by about 0.75 Degs C
3. The following greenhouse gases have increased in the atmosphere and can be attributed to man's emissions.
Carbon dioxide by 40 %
Methane by 150%
Nitrous oxide by 16 %
4. These emissions are have increased the global temperature enough to produce knock on effects:-
a.Evaporating more water vapor which also adds to the greenhouse effect.
b. Shrinking ice cover leading to reduced albedo.
The challenge for those who don't accept the above is make a reasonable case that man has not contributed to the global warming that has occurred over the last 100 years