Quite a few people believe that the 'proof' of climate change is in the sophisticated mathematical climate models. Not so.  The science of climate change is based on a knowledge of physics and chemistry.  Anthropogenic global warming of the Earth's atmosphere is the inevitable conclusion based on understanding the carbon cycle, the green house effect, tracing sources through carbon dioxode isotopes, and so on.  The role of the mathematical models is different.  They follow on from our knowledge of climate, but predicting the average global temperature for a given future date is educated guess work.  And yes, science is often 'settled'.  Not all the conclusions we draw from the fundamentals of science, are, however.