Study: Natural Gas No Bridge to Zero Fossil Fuel Future

by Duane Nichols on January 9, 2013

Galata Bridge in Istanbul

By Susan Phillips, StateImpact (NPR), January 7, 2013

Proponents of natural gas tout new shale deposits, such as Pennsylvania’s Marcellus, as a way to reduce carbon emissions while the world eases itself off fossil fuels, and moves toward alternatives such as wind and solar. Natural gas power plants emit less CO2 than coal, which still dominates electricity generation worldwide. In the U.S., low natural gas prices have allowed natural gas to catch up with coal-fired electricity. But this “bridge fuel” scenario is controversial.

Some say the world is warming too quickly to even consider the concept legitimate. Still others say the process of extracting natural gas at the wellhead emits enough methane, a greenhouse causing gas, to negate any benefits of lower carbon dioxide emissions at power plants.

Climatic Change, a peer-reviewed scientific journal, has just published online a report that has something to make both sides happy and sad. Written by Michael Levi, “Climate consequences of natural gas as a bridge fuel,” is one of the only reports to look at the issue from a vantage point of global emissions reduction goals. The bottom line, says Levi, is that any potential “natural gas bridge” would be useless because it would be so short. He does say, however, that natural gas can play a role in easing nations off of coal.

“Collectively, these results suggest that it may be useful to think of a natural gas bridge as a potential hedging tool against the possibility that it will be more difficult to move away from coal than policymakers desire or can achieve, rather than merely (or primarily) as a way to achieve particular desired temperature outcomes.”

Natural gas opponents will cheer these results. But they won’t be too happy about Levi’s conclusions about natural gas emissions at the wellhead. Levi says when lowering emissions to halt climate change, the methane that leaks from natural gas wells is not enough to offset the benefits of lower CO2 emissions at the power plant.

“Moreover, in most cases where stabilization is near 550 ppm CO2, even high rates of methane leakage do not fundamentally alter the conclusion that replacing coal with gas can substantially lower peak temperatures relative to what they would be if a transition away from coal were instead delayed. In particular, if so-called “tipping points” can be triggered by exceeding particular temperature thresholds, methane leakage in the context of bridge fuel scenarios will have at most a very small impact on the odds that those thresholds will be crossed. This is true even if steps to reduce methane leakage can yield benefits exceeding costs.”

NOTE: The above picture shows a  rainbow over the Galata bridge and Galata Tower after a rainy day in Istanbul on November 23, 2012.

{ 1 comment… read it below or add one }

Jerry J. Mooney May 3, 2013 at 7:04 am

Now it is clear. It is too late to use Natural Gas as a BRIDGE FUEL. This is because we are already at 400 ppm of carbon dioxide in the atmosphere. We are already seeing natural gas taking over the fossil fuel industry, being used for home heating, for fueling alternative-fuel vehicles, for replacing coal in existing power plants, for use in the chemical industry as a feed-stock, and now as LNG for export to foreign countries.

Think of all the leakage, all the flaring, all the pipeline mishaps, all the compressor station accidents, all the seepage underground, all the migration from fracked shale, ….. on and on.

Methane is a hightly potent greenhouse gas, many times that of carbon dioxide.

It is too late to consider natural gas (methane) as a BRIDGE FUEL, its time has passed!

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