http://www.nationalcenter.org/NPA570.html
Just a summary from the page
Introduction and summary
The legislation ostensibly is intended to cut U.S. industrial emissions of greenhouse gases in an effort to reduce the risk of catastrophic global warming. Senator Lieberman has estimated the bill would reduce overall U.S. greenhouse gas emissions by up to 63% by 2050.1 The policies the legislation would impose, however, have little hope of meeting this target and would likely have little impact on the climate even if it did.
Lieberman-Warner would, however, significantly slow the U.S. economy and increase the cost of energy and consumer products. It also would disrupt international commerce.