I am sure that there are some natural reasons for some of the changes that have been happening with our climate. But I believe that most has been helped along by all the chemicals that upset the natural balance of our climate. We pump so much into the air, how could it not have an effect on the delicate balance of nature.
While science can do some miraculous things, predicting catastrophic events accurately is not one of them. Climate changes are most likely part of much larger weather patterns that span thousands of years. With only a few facts, but much unsupported speculation, there is nothing really solid for science or government to base any long-term policies on.