mitch212k wrote:
+1 ty 4 trying man, but i cant c if it says how long the theory has been around
That depends entirely on what sort of theory of global warming you are looking at. Global warming is not a theory, just like evolution is not a theory. They are both termed theories by many people who do not realise that they are actually a collection of many constituent theories.
The greenhouse effect was discovered a very long time ago, by Fourier - who I hate because of all the horrible transforms he invented that I've struggled with at uni.
More modern theories you may want to be aware of include theories by Mann, Milankovitch insolation theory and of course you will want to look at the IPCC reports.