Natural gas, long seen as a cleaner alternative to coal and an important tool in the fight to slow global warming, could be bad for the climate, a new study concludes, unless companies can eliminate the leaks that plague its use. .
The study found that natural gas leakage is only 0.2 percent to make natural gas as big a driver of climate change as coal. That’s a small margin of error for gas known to leak from drilling sites, processing plants and pipelines that carry it to power plants or homes and kitchens.
The bottom line: If the gas leaks, even a little bit, it’s “as bad as coal,” said Deborah Gordon, principal investigator and environmental policy expert at Brown University and the Rocky Mountain Institute, a nonprofit research organization focused on clean energy. . “It cannot be considered a good bridge or an alternative.”
The peer-reviewed study, which also included researchers from Harvard, Duke and NASA universities, is due for publication next week. In the Journal of Environmental Research Lettersadds to a large body of research that has poked holes in the idea that natural gas is a suitable transition fuel for a future powered entirely by renewable energy sources, such as solar and wind power.
The findings raise tough questions about how much money the world’s nations should invest in gas infrastructure to stave off the worst of global warming. $370 The Reducing Inflation Act passed by the US Congress last year, designed to move the country away from fossil fuels and toward renewables, includes credits that can be applied to some forms of natural gas.
When power companies generate electricity by burning natural gas instead of coal, they emit only about half the amount of planet-warming carbon dioxide. In the United States, the shift from coal to gas, driven by a boom in oil and gas fracking, has helped reduce carbon emissions from power plants. by about 40 percent Since 2005.
But natural gas is mostly methane, which is a more effective planet-warming gas, in the short term, than carbon dioxide when it escapes without burning into the atmosphere. And there is growing evidence that methane does just that: leaking from gas systems in far greater amounts than previously thought. Sensors and infrared cameras are helping to visualize large methane leaks from oil and gas infrastructure, and increasingly powerful satellites are revealing “superemission” episodes from space.
The latest study advances this science in several ways. It has researched and compared natural gas and coal emissions over the entire “life cycle,” from exploration and mining for the fuel to its distribution and combustion. The researchers also looked at natural gas and coal for all of their energy uses, other than generating electricity. Gas, in particular, is widely used as an industrial, commercial, and residential energy source for fuel, steam, heating, and power.
The study also took into account one curious effect of emissions from burning coal: Some emissions could actually have a short-term effect that offsets some of the warming.
This is because, in addition to carbon dioxide, coal emits sulfur dioxide, which forms sulfate aerosols in the atmosphere. These aerosols reflect incoming sunlight back into space, helping to cool the atmosphere.
Sulfur dioxide has other serious problems. It causes serious harm to human health and the environment. Coal-fired power plants are a major source of other toxic forms of air pollution. Previous research suggested Switching from coal to gas is less harmful to public health.
There are other trade-offs to consider. Carbon dioxide, emitted in abundance by coal-fired power plants, persists in the atmosphere much longer than methane, which dissipates after a few decades. So focusing on methane leaks from gas infrastructure, at the expense of controlling carbon emissions, means the world may mitigate some warming in the short term, but still face dangerously high average temperatures for many decades to come. However, with the consequences of climate change already causing havoc around the world, controlling methane would be a way to slow warming immediately.
Under pressure from its climate impact, the oil and gas industry has said it has made progress in detecting and capping rogue emissions. Experts say independent monitoring and verification of these claims will be crucial.
Robert Howarth, an Earth systems scientist at Cornell University who raised the alarm about a methane leak more than a decade ago, called the analysis solid.
“Their conclusion is to suggest again that natural gas may not be at all better for the climate than coal, especially when viewed in terms of warming over the next 20 years or so, which is of course a critical time” for achieving climate goals, he said in a letter. e-mail.
“I hope that the political world and political leaders of the world will pay attention to this, as I fear that many of them will remain very focused on reducing the use of coal, even if this leads to an increase in gas consumption,” said Dr. Howarth. “What the world needs is to move away from all fossil fuels as quickly as possible, to a future of 100 percent renewable energy.”