The U.S. could cut its carbon dioxide emissions by 8%, almost half of the country’s unofficial 2020 emissions reduction goal, by increasing use of natural gas plants, according to a new M.I.T. report.

The report, “The Future of Natural Gas,” found that taking coal-fired power plants offline and ramping up natural gas plants is “the lowest cost way to reduce carbon dioxide emissions by up to 50%.”

Released Thursday, the M.I.T. Energy Initiative study, which deals principally with the U.S., follows close on the heels of a study by the International Energy Agency which asked in its title, “Are We Entering A Golden Age of Natural Gas?”

Both studies concluded that abundant natural gas, particularly “unconventional” gas locked in shale rock formations, will assume a critical position in the global energy mix.

The M.I.T. report found that natural gas power will play an important role in backing up renewable energy sources but will not displace them, a fear voiced by IEA head Nobuo Tanaka earlier this week. In fact, increased use of renewable energy will likely come at the expense of natural gas-fired generation as solar, wind, and other renewable technologies grow more cost efficient.

The M.I.T. researchers also struck a more optimistic note about the climatic effects of increased gas usage and provided the most comprehensive rebuttal to date of a controversial recent study on the greenhouse gas emissions related to the hydraulic fracturing of shale gas.

The report took a harsh view of a recent study by Cornell University Professor Robert Howarth on the emissions of methane, the principal component of natural gas, from drilling, transportation and end use of gas.

The widely published conclusions found greenhouse gas emissions from shale gas drilling were worse than emissions from coal.

The M.I.T. report devotes an entire appendix to rebutting the Howarth study and notes the report does “not appear to be comprehensive, use common assumptions or recognize the progress made by producers to reduce methane emissions, often to economic benefit.”

In an interview, study co-chair Henry Jacoby, a professor of management at M.I.T., called the Cornell study, “a really poor piece of work.”

Still, the M.I.T. researchers acknowledged uncertainties about production methods such as hyrdraulic fracturing, or fracking, including the migration of natural gas into freshwater zones.

Jacoby said he found a recent study on the migration of natural gas troubling.

He added, “There are problems like this for all energy sources.”

This story appears by consideration of the GE-sponsored blog The Txchnologist.

Picture: The autograph of US President Barack Obama is seen on a machine while he toured a research laboratory at the Massachusetts Institute of Technology (MIT), an institution that has been developing cutting edge clean energy technology, in Cambridge, Massachusetts, on October 23, 2009. AFP PHOTO/Jewel SAMAD (Photo credit should read JEWEL SAMAD/AFP/Getty Images)