New York, Feb 26 (IANS): Technology-driven cost reductions in fossil fuels will lead us to continue using all the oil, gas, and coal we can, unless governments pass new taxes on carbon emissions, according to a study.

"If we don't adopt new policies, we're not going to be leaving fossil fuels in the ground," said co-author Christopher Knittel, energy economist at the Massachusetts Institute of Technology (MIT).

"We need both a policy like a carbon tax and to put more R&D money into renewables," Knittel added.

Published in the Journal of Economic Perspectives, the study found that burning all available fossil fuels would raise global average temperatures 10 to 15 degrees Fahrenheit by the year 2100.

It also found that burning oil shale and methane hydrates, two more potential sources of copious fossil fuels, would add another 1.5 to 6.2 degrees Fahrenheit to that.

"You often hear, when fossil fuel prices are going up, that if we just leave the market alone we'll wean ourselves off fossil fuels," added Knittel. "But that's not going to happen any time soon," he noted.

At least two technological advances have helped lower fossil fuel prices and expanded reserves - hydraulic fracturing, or fracking, which has unlocked abundant natural gas supplies, and the production of oil from tar sands, according to the authors.

"There are hydrocarbons that we can now take out of the ground that 10 or 20 years ago we couldn't," Knittel observed.

As a result of improved oil and gas extraction techniques, "we have consistently had about 50 years' worth of accessible oil and natural gas reserves in the ground over the last 30 years", the researcher noted.

"It's certainly the case that solar and wind prices have fallen dramatically and battery costs have fallen," he said.

"But the price of gas is a third almost of what it used to be. It's tough to compete against $1.50 gasoline. On the electricity side... the cheap natural gas still swamps, in a negative way, the cost of solar and even wind," Knittel added.

The authors suggested that new solar techniques -- such as thin-film layers that integrate solar arrays into windows -- may lead to even steeper reductions in the price of renewables, especially as they could help reduce installation costs, a significant part of the solar price tag.