They argue the legislation would ultimately cost consumers too much and hurt American businesses.
Bennett, in a Senate floor speech on Thursday, said the debate over climate change is "warranted" but that the bill itself misses the target.
"I'd like to make a point that I think everybody ignores: this is a global problem," Bennett said. "[This] bill attempts to solve it with a national solution."
Bennett motioned to a chart showing that while carbon dioxide emissions in the United States may decrease under provisions of the bill, they would still increase globally.
The Utah senators' opposition aside, the bill is likely headed for defeat this week after supporters failed to marshal enough votes to continue debate.
The apparently doomed legislation, is sponsored by Sen. John Warner, R-Va., and Sen. Joe Lieberman, an independently elected Democrat from Connecticut. It would require power plants, refineries and other businesses emitting greenhouse gases to reduce their emissions by 19 percent by 2020 and even more by 2050. The measure would also launch a "cap-and-trade system" by which companies could buy pollution credits from more eco-friendly businesses.
Hatch voted against even proceeding on the climate change legislation saying that it may not be the most effective approach to reducing carbon monoxide emissions, but it "may be the most harmful economically."
Hatch warned that if the United States alone reduces its CO2 emissions, other countries would not, leaving American companies disadvantaged against foreign competitors.
"I always thought Democrats wanted to increase manufacturing jobs and reduce CO2," Hatch said. "Unless we require the same standards of our international competitors, the bill would certainly reduce jobs and increase global CO2 emissions."
