I dont have any more knowledge or expertise about global warming than most Americans, but I would tend to give more credibility to a group like the Intergovernmental Panel on Climate Change (IPCC) than to Sen Imhofe. Just as an aside, Imhofe's two top contributors are the oil lobby and the electric utility lobby.
The IPCC assessments - that conclude that human activity is a contributing factor of global warming - involve thousands of scientists from over 120 countries who, over a period of years, develop detailed reports on climate change. The peer-review process is far more extensive than even the most prestigious scientific journals – the most recent report was reviewed by more than 1,000 top experts.
There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.
http://www.grida.no/climate/ipcc_tar/wg1/007.htm
For more on the IPCC assessment process:
http://www.ucsusa.org/global_warming...t-process.html
The National Academy of Sciences, an independent organization created by Congress to provide scientific guidance recently a study recently with the same general conclusions.
Maye a picture helps. This graphic of the melting of the polar ice cap over the last 26 years is pretty compelling.
http://www.everybodysweather.com/Sta...lter/index.htm
It obviously doesnt suggest that the decline is human induced. You have to read the numerous independent and peer-reviewed, studies out there to see the impact of human activity as a contributing factor as opposed to just natural occurences.
Then decide for yourself if we should consider policies to address the issue responsibly or just ignore it, vilify any scientist or politician who expresses concern, and hope for the best.