Report: Fossil fuels could raise global temperatures 10 degrees by century's end

“Even doubling our current rate of decarbonisation, would still lead to emissions consistent with 6 degrees of warming by the end of the century. To give ourselves a more than 50% chance of avoiding 2 degrees will require a six-fold improvement in our rate of decarbonisation,” Leo Johnson, a partner in PricewaterhouseCoopers’ sustainability and climate change practice, wrote in the report.

To meet that goal, the world would need to reduce its carbon intensity by 5.1 percent per year through 2050. From 2010 until 2011, carbon intensity fell 0.7 percent worldwide, the report said.

Fossil fuels are inhibiting that progress, the report said. While overall worldwide carbon intensity fell, energy-related emissions rose 3 percent.

The United States, for its part, has seen its carbon dioxide emissions drop to a 17-year low. The report said U.S. energy-related emissions fell 1.9 percent in 2011, while its overall carbon intensity dropped 3.5 percent.

The energy-related emissions decrease is partially a result of a mild winter and a greater concentration of more fuel-efficient vehicles.

But most of the U.S. carbon reduction is credited to increased use newfound natural gas abundance. That has helped push the U.S. to export its coal at record levels this year, therefore offering little, if any, net benefit to global emissions reduction targets.

The report praised natural gas for its carbon-cutting qualities, but feared a reliance on it could stunt progress in developing other energy sources.

“But low gas prices may also reduce the incentive for investment in lower-carbon nuclear power and renewable energy,” the report said.

The report said growing use of natural gas in emerging economies could create a dependence on fossil fuels. It noted carbon emission reduction “appears to have stalled” in major emerging economies such as China and India.

“Avoiding lock-in will require discipline in governments that encourage gas generation, to ensure that incentives are not diverted away from renewable energy,” the report said.