"Globally, power generation emits nearly 10 billion tons of CO2 per year. The U.S. with over 8,000 power plants out of more than 50,000 worldwide, accounts for about 25% of that total," the survey found.
The report claimed that the biggest U.S. CO2 emitter is Southern Co. whose power plants belch out 172 million tons of the principal greenhouse gas annually, followed by American Electric Power Company Inc., Duke Energy Corp., and AES Corp. The state with the biggest CO2 emissions from electricity generation is Texas which accounts for 290 million tons of emissions, followed by Florida (157 million tons) and Indiana (137 million tons).
China's largest emitter is Huaneng Power International that accounts for 292 million tons of CO2 emissions.
Researchers said U.S. emissions were high partly due to high living standards, but also differences in energy policy.
"Europeans, with comparable living standards, emit less than half the power sector CO2 of the average American," said CGD president Nancy Birdsall.