Climate

Memo To Obama: Expanded Natural Gas Use Worsens Climate Change

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A new study confirms that “increased natural gas use for electricity will not substantially reduce US GHG [greenhouse gas] emissions, and by delaying deployment of renewable energy technologies, may actually exacerbate the climate change problem in the long term.”

This Environmental Research Letters study should be sobering to fans of expanded gas use who care about global warming — such as the Environmental Defense Fund and President Obama — because it is true even if methane leakage from gas production and delivery could somehow miraculously be reduced to zero.

“Natural gas has been presented as a bridge to a low-carbon future, but what we see is that it’s actually a major detour,” explained lead author Christine Shearer in the news release. “We find that the only effective paths to reducing greenhouse gases are a regulatory cap or a carbon tax.”

Although many fracking advocates pretend otherwise, this is not a new finding. Indeed, most claims that shale gas will significantly reduce U.S. carbon emissions in the future are based on little more than hand-waving and wishful thinking, as the literature makes clear. That’s because — even if we ignore methane leaks — those claims assume natural gas is replacing coal only, rather than replacing some combination of coal, renewables, nuclear power, and energy efficiency, which is what is happening in the real world.

Last year, Stanford’s Energy Modeling Forum published the results of economic modeling by more than a dozen different expert teams. The figure below shows the results of the models that extend to 2050 (though the results are not substantially different if the modeling stops at 2035).

More abundant, cheaper shale gas (dark blue) has little impact on annual growth in U.S. CO2 emissions through 2050 compared to low shale gas case (light blue). This is true for all six energy-economy models featured here. Deep cuts in CO2 require a rising carbon price (green).

More abundant, cheaper shale gas (dark blue) has little impact on annual growth in U.S. CO2 emissions through 2050 compared to low shale gas case (light blue). This is true for all six energy-economy models featured here. Deep cuts in CO2 require a rising carbon price (green).

Why doesn’t cheap, abundant natural gas matter much for long-term U.S. CO2 trends? Over time, and especially post-2020, “natural gas begins to displace nuclear and renewable energy that would have been used otherwise in new power plants under reference case conditions.”

“Cutting greenhouse gas emissions by burning natural gas is like dieting by eating reduced-fat cookies,” explains Prof. Steven Davis, the principal investigator of the new study. “It may be better than eating full-fat cookies, but if you really want to lose weight, you probably need to avoid cookies altogether.”

To extend the metaphor, those reduced-fat cookies are not simply replacing full-fat ones, they are also replacing fruits and other healthy snacks.

Dr. Shearer explains the study’s findings in this video:

It bears repeating that natural gas is mostly methane, (CH4), a super-potent greenhouse gas, which traps 86 times as much heat as CO2 over a 20-year period. So even small leaks in the natural gas production and delivery system can have a large climate impact .

Observations and analysis make clear that methane leakage is actually quite high — enough to gut the entire benefit of switching from coal-fired power to gas for decades. Sadly, the kind of national regulations that could seriously cut leakage are not in our foreseeable future. So you’ll likely be dead and the climate ruined by the time expanded natural gas production and use has a net climate benefit.

To return to the cookie metaphor, if we were to consider the impact of methane leaks, that would be like spreading butter on the reduced-fat cookies before eating them.

It’s time to stop the hand-waving claims that fracking represents a healthy, long-term strategy for addressing the climate crisis. We know the winning strategy, and, if your goal is a significant and enduring cut in U.S. carbon pollution, a price on carbon is the place to start.