Natural Gas and Greenhouse Gasses
The boom in production of natural gas is shaking up energy markets around the world, but what does it mean for the world’s climate? Some scientists say the glut of gas could bring a global warming benefit by knocking out dirtier coal. But others say gas is more likely to add to our climate conundrum. Living on Earth’s Jeff Young reports on the sometimes heated debate about natural gas and greenhouse gases.
GELLERMAN: Getting natural gas out of the ground presents one set of problems. Another is what happens when it goes into the atmosphere - the gas can affect climate change. Several studies recently looked at the problem but as Living on Earth’s Jeff Young reports, they came to very different conclusions.
YOUNG: The International Energy Agency calls it a “Golden Age of Gas,” an unprecedented boom in global supply. The glut of gas makes possible a large-scale switch away from far dirtier coal to generate electricity and power industrial boilers. There’s little dispute that switching to gas would help clean the air of coal’s poisonous pollutants. But there is vigorous debate about what gas might mean for greenhouse gases. Massachusetts Institute of Technology’s new report “The Future of Natural Gas” has a positive outlook.
MEGGS: The possibility of reducing CO2 emissions in the United States by 50 percent over the next 30 years is extraordinary. It’s an extraordinary opportunity.
YOUNG: That’s MIT visiting engineering professor Tony Meggs, a lead author of the study along with Melanie Kenderdine, who directs MIT’s Energy Initiative. Kenderdine looked at switching from coal to the more efficient gas-fired power plants the country already has but does not use as often. That alone could reduce carbon emissions from the U.S. power sector by a fifth.
KENDERDINE: We really need significant carbon emission reductions now. And the only practical, large-scale, immediate action that you could take are energy efficiency and switching from coal generation to gas generation using that surplus capacity.
MEGGS: And I think just to add to Melanie’s point here, we weren’t pushing gas into the power sector - we simply asked the model question: what’s the most economical way to reduce CO2? And because of the relatively low cost of gas supplies, that is the most economical route.
YOUNG: The MIT report, which was partly supported by the gas industry, echoes earlier work by the World Resources Institute that says natural gas can knock off King Coal if laws force business to deal with coal’s carbon emissions and toxic pollutants. In the long run, both studies say we’ll need even cleaner energy sources, but the common refrain is that gas can be the bridge to that cleaner energy future.
Professor Kevin Anderson says that bridge looks a bit shaky. Anderson directs the Tyndall Centre for Climate Change Research at the University of Manchester in the UK, which produced a study that doubts whether gas will really substitute for coal.
ANDERSON: We hear these sorts of arguments all the time. I mean, in this idealized world, that we might have in a theoretical model on a computer or in a university, perhaps we can imagine one substituting one for the other. In the real world, what we actually see is people are combusting whatever they can lay their hands on.
YOUNG: Anderson says without a global cap on carbon emissions, it’s more likely that gas will just move coal around to be used somewhere else. If gas displaces coal in one country, it lowers the price of coal - making it more attractive to another growing economy.
ANDERSON: And we have to remember that the only thing the climate cares about is the total amount of CO2. It doesn’t matter whether it comes from the U.S., from China, from Nigeria, from the UK - it doesn’t matter where that carbon dioxide comes from, it only matters that we’re putting carbon dioxide into the atmosphere. So substitution does not matter if we are then going to use the coal elsewhere.
YOUNG: The Tyndall Centre’s report also warns that cheap gas might undermine investments in cleaner renewable energy. Other analysts argue that gas is often a partner to renewables that smoothes out the intermittent power supply from wind and solar. But the biggest challenge to gas as a global warming good guy comes from a Cornell University study. Cornell professor Robert Howarth argues that gas from hydrofrack drilling is no better than coal. Howarth brought attention to the greenhouse gas methane that leaks from those shale gas drilling operations.
HOWARTH: If you look at the total greenhouse gas emissions, including methane release and not simply carbon dioxide, then in fact shale gas has a very large greenhouse gas footprint - making it perhaps the most high-impact fuel on the global environment of any fossil fuel.
YOUNG: Howarth’s conclusions are controversial. Industry critics say he overstates the amount of gas that leaks and understates the efficiency of gas power plants. At MIT, Melanie Kenderdine criticizes the short time frame Howarth uses to measure the global warming potential of methane versus carbon dioxide. Methane is a potent greenhouse gas but lasts in the atmosphere only a dozen years or so. CO2 does its damage for a century or more. Climate scientists focusing on CO2 generally use a 100-year time scale. Kenderdine says Howarth’s most alarming results came from using a 20-year time frame.
KENDERDINE: That of course increases the impact of methane. The concern of the climate scientists here is that decreases the focus on what they believe is the more serious problem, which is CO2 emissions, which reside in the atmosphere for hundreds of years.
YOUNG: Howarth vigorously defends his findings and says the 20-year time scale is a useful one, given concerns about the climate approaching a tipping point in the coming decades.
HOWARTH: We’re in a stable state at the moment, relatively stable, but if we force it into some new trajectory, past some tipping point, then society’s in a lot of trouble. The shorter time frame is critical if you are serious about dealing with global warming.
YOUNG: And Howarth adds, so far, his is the only peer-reviewed study on the matter. More are sure to come as the full climate impact of gas gets more scientific attention. There’s one area where most of the researchers are in agreement: gas surely won’t improve the climate picture if it’s left purely to the whims of the current energy marketplace. The Tyndall Centre’s Kevin Anderson says it’s really about the energy policy we decide to set.
ANDERSON: It is indeed. At the end of the day, we need the correct policy environment within which markets and we as individuals can operate. And if that is put in place, then we can start to deal seriously with climate change. If we choose not to put that policy framework in place, then we will simply not address climate change and we will have to deal with the impacts.
YOUNG: And as things are now, the production of natural gas is moving full speed ahead while policy on greenhouse gases is creeping along at best. For Living on Earth, I’m Jeff Young.
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