There is no evidence that man has caused climate change.

http://gem-garnet.blogspot.com/

This is one of many blogs of W. Dan Hausel.  He is one of the signers of a petition of over 30,000 scientists who says that there is no evidence that global warming or climate change has come about because of anything man did or does.  Below is an excerpt from his blog. 

 The outcrops also provide examples of extreme natural environmental conditions in the geological past and provide evidence of Nature-caused global freezing and global warming, long before it became a popular cult theme of politicians and environmentalists. Global warming and freezing events are common throughout earth’s history: >30 thousand scientists http://www.petitionproject.org profess that there is no evidence for Man-caused global warming (which recently was modified to Climate Change since the last 9 years have brought lower than normal temperatures). Good o’ Mother Earth continues to change her environment without our help or interference. Mother Earth is unstable and always has been. I remember when I was an undergraduate and future geologists were taught that the earth was moving into another ice age. Several alpine glaciers were measured and shown to be expanding at that time.