The idea of cutting harmful Earth-warming gases by switching from coal and oil to cleaner-burning natural gas seemed like a no-brainer. Natural gas produces less than half the amount of carbon dioxide, the prime greenhouse gas. And there's plenty of it, thanks to new technologies such as hydraulic fracturing ("fracking"), horizontal drilling and seismic imaging.
But there's a catch.
A new study out Wednesday says that cheap, abundant natural gas will actually harm the environment. While it will displace coal and other dirty fuels, it will also encourage people to burn more, as well as undercutting non-fossil fuel sources of energy such as wind, solar and nuclear power.
"When we looked at it, abundant gas is not going to solve the climate change problem on its own without accompanying climate policies," said Haewon McJeon, a staff scientist at the Department of Energy's Pacific Northwest National Laboratory, the lead author on the study appearing in the journal Nature. "The main thing we were hoping for is that natural gas would displace coal, and would decrease emissions significantly. That's not the only effect. It will also displace coal but also wind. We still get some reduction in (greenhouse gas) emissions, but one more effect is the first rule economics: If things are cheap, people will consume more."
Another monkey wrench with natural gas is the production of methane during gas drilling. Methane is more powerful than carbon dioxide when it comes to trapping heat in the atmosphere.
The new study didn't endorse any specific climate policies, but the implication is that renewable energy still needs some kind of subsidies or price protections if governmental leaders are serious about putting less carbon dioxide in the air.
McJeon and colleagues tackled this question with five separate models used to predict energy consumption and carbon emissions through 2050. The project included scientists from Austria, Australia, Germany, Italy and the United States.
Jae Edmonds, a principal investigator on the study and also a scientist at PNNL, says that using five different methodologies gave the study more heft.
"Rather than us trying to publish a study that was our study alone, we teamed up with a set of other colleagues, each of whom has their own unique approach," Edmonds said. "One of the strengths is you have this qualitative consistency that emerges. It gives you more confidence than if there was just one study."
John Weyant, professor of management science and engineering at Stanford University, said there still may at least one benefit to natural gas -- it will help transition away from coal.
"Abundant gas might make climate policy easier by making backing (away from) coal less costly, especially in the short run," said Weyant, who was not associated with the study. "So abundant gas may get you on your way to a low greenhouse gas future but is extremely unlikely get you all the way there."
McJeon and Edmonds said their study looked at global trends in both natural gas comsumption and carbon emissions. The next phase will look at regional differences between the big emitters of the United States, China and India, for example, and what role natural gas play in those economies.