This issue has been politicized by both sides. It is hard to know who to trust especially considering both sides have agendas surrounding the topic. I heard this guy speak about global warming. He seems to be on track to me.

http://www.ac.wwu.edu/~dbunny/research/global/glacialfluc.pdf

I will condense it for ya. Prof Esterbrook says the planet has gone through 20 heating and cooling cycles in the last 500 years, over all showing a warming trend through the cycles. By way of percentage the warming cycles hasn't been more since the industrial revolution, than they were before the industrial revolution. To me this tends to debunk global warming as the LWWJ's define it, and makes it appear to be a natural occurring phenomena that we can't do anything about.

There is another scientist (can't remember his name) who has been studying the solar cycles as they pertain to global warming. Apparently he has been able to accurately predict these types of heat waves and cooling trends. I would like to read more about his work if anyone know his name I would appreciate it if you would forward it on.