Carbon dioxide emissions are falling dramatically in the U.S., government officials say.
The findings were published in a report by U.S. Energy Information Agency earlier this month.
Officials state that CO2 emissions released into the atmosphere during the first four months of 2012 were comparable to 1992 levels, marking a 20-year low.
The drastic reduction has been credited to the availability of natural gas, a cheap and cost-effective alternative to coal, the dirtiest of the fossil fuels.
"There's a very clear lesson here. What it shows is that if you make a cleaner energy source cheaper, you will displace dirtier sources," said Roger Pielke Jr., a climate expert at the University of Colorado, in a statement.
Widespread conservation efforts and renewable energy have also played a part in the shift.
Environmentalists are quick to point out that while natural gas burns cleaner than coal, it still emits some CO2 into the atmosphere -- and that CO2 levels are rising elsewhere in the world.
Still, some researchers have expressed "cautious optimism" about the findings.
With files from the Associated Press