(the answer may not be what you expected)
Here are additional links of reputable and reliable websites that will assist the visitor in learning more about our climate.
While the climate debate is certainly a contentious one, I think if we let the facts speak for themselves, the truth can be found. We live in a global laboratory. I dont think anyone would disagree that temperatures warmed some from the cool 1960s and 1970s to the late 1990s, (it has been cooling since). The question is, was man the primary source of change or nature? We live in a laboratory, and Mother Nature will soon show us what the answer is.