A new peer-reviewed paper to be published in Environmental Research Letters next week adds to the accumulation of studies demonstrating why our love affair with natural gas needs to be ended posthaste. (The study’s abstract can be read below.)
For years, natural gas—composed primarily of methane—has been touted as a bridge fuel to a new world of sustainable clean energy, a way to get off coal without waiting for renewables (and many would add nuclear) to fulfill all our electricity needs. This has worked in the United States to help reduce greenhouse gas emissions by 40% since 2005, with coal’s share of U.S. electricity generation dropping last year to less than 20%. That’s because burning methane releases on average about half the greenhouse gas emissions of coal.
But there’s a big problem. Over 20 years, unburned methane has a global warming potential that is 84 times greater than that of carbon dioxide emitted by burning coal. Methane leaves the atmosphere far more quickly than carbon dioxide, but even after a century, it has 24 times the global warming potential of CO2. Methane concentrations in the atmosphere right now are about 170% higher than in the pre-industrial times and surging. Scientists say methane emissions are responsible for about 30% of the warming we’ve seen in the industrial era so far. About 40% of the methane comes from natural sources and around 60% results from human activities—anthropogenic emissions.
Last year, as reported by the 2023 Global Methane Tracker, the energy sector worldwide emitted 135 million tons of methane, just slightly less than the all-time record in 2019.
The natural sources include melting permafrost, which could theoretically release titanic quantities of methane as the Arctic continues to warm four times faster than the planet’s average. But scientists have different takes on just how severe of a climate impact will come with permafrost melt. The human sources are agriculture, landfills, and leaks from oil wells and … natural gas-fracking operations.
A study found that pipelines carrying fracked gas in the Permian Basin were leaking at least 14 times more methane than previously accounted for.
As we’ve seen from various studies over the past few years, a lot more of the stuff is leaking in the extraction and transportation processes than was previously told to government monitors by the industries doing the extracting. Last year, a study found that pipelines carrying fracked gas in the Permian Basin oil fields of Texas were leaking at least 14 times more methane than previously accounted for. Surprise! Another study in 2022 in found that Methane Leaks in New Mexico Far Exceed Current Estimates. And there was this report about prodigious Gulf of Mexico leaks.
Hiroko Tabuchi at The New York Times reports about the latest study:
It takes as little as 0.2 percent of gas to leak to make natural gas as big a driver of climate change as coal, the study found. That’s a tiny margin of error for a gas that is notorious for leaking from drill sites, processing plants and the pipes that transport it into power stations or homes and kitchens.
The bottom line: If gas leaks, even a little, “it’s as bad as coal,” said Deborah Gordon, the lead researcher and an environmental policy expert at Brown University and at the Rocky Mountain Institute, a nonprofit research organization focused on clean energy. “It can’t be considered a good bridge, or substitute.” […]
The findings throw up difficult questions about how much more money the nations of the world should invest in gas infrastructure to ward off the worst of global warming. The $370 billion Inflation Reduction Act passed by the United States Congress last year, designed to move the country away from fossil fuels and toward renewables, includes credits that would apply to some forms of natural gas.
Robert Howarth, a prominent earth systems scientist who who has been warning about methane leaks for more than 10 years but wasn’t involved in this study, said of the researchers in an email to the Times: “Their conclusion is to once again point out that natural gas may not be any better at all for the climate than is coal, particularly when viewed through the lens of warming over the next 20 years or so, which of course is a critical time” for meeting climate targets. “I do hope the policy world and the political leaders of the world pay attention to this, as I fear too many remain too fixated at simply reducing coal use, even if it results in more gas consumption. What the world requires is to move away from all fossil fuels as soon as possible, to a 100% renewable energy future.”
Meanwhile, C-SPAN this week was brimful of Republican amateur climatologists behaving in congressional environmental hearings as if their opinions are equivalent to that of scientists with, say, two decades of Greenland ice core research. The idea of getting off natural gas to address climate change is something these politicians view as anti-American heresy, particularly as regards their pocketbooks and those of their patrons.
The reality, as Howarth said in a 2019 interview with Blaine Friedlander at the Cornell Chronicle: “Reducing methane now can provide an instant way to slow global warming and meet the United Nations’ target of keeping the planet well below a 2-degree Celsius average rise. (3.6 degrees Fahrenheit). This recent increase in methane is massive. It’s globally significant. It’s contributed to some of the increase in global warming we’ve seen and shale gas is a major player. If we can stop pouring methane into the atmosphere, it will dissipate. It goes away pretty quickly, compared to carbon dioxide. It’s the low-hanging fruit to slow global warming.”
More than 130 nations have pledged to cut back on methane production. China and the United States agreed to work together to reduce their methane emissions and that agreement seems to be still operational despite the various frictions between the two nations. The Inflation Reduction Act has relevant provisions to reduce methane emissions. The United States has also enacted a methane fee as a disincentive to companies that otherwise would ignore leaks. We’ll see how well this pay-to-pollute approach works compared with a cease-and-desist letter.
The Global Methane Tracker found that in 2022 the worldwide energy industry was responsible for emitting 135 million tonnes of methane into the atmosphere, only slightly below the record high seen in 2019. Today, the world’s energy sector accounts for around 40% of total methane emissions attributable to human activity, second only to agriculture.
If we actually were to cut human-caused methane emissions by 30% globally this decade from the 2020 levels, which is the time-frame of the Global Methane Pledge, it would avert at least 0.2°C (0.36F) in global warming by 2050. But how likely is that without a serious policy change?
Our leaders need to remember that the operative word on ending the burning of fossil fuels is ASAP. Yet we are currently building new natural gas infrastructure with a 50-year lifespan, with tax money helping pay the tab. New liquefied natural gas terminals are being built and others proposed or in the pipeline headed for approval. Oil and gas drilling companies are still getting leases to carry out their operations on public land, including in sensitive ocean waters that still bear the marks of their previous recklessness. Around the world, the hunt for new oil and gas deposits has not slowed.
This is the wrong path.
If we expect to have any chance of mitigating some of the damaging climate and biodiversity impacts that humans have collectively wrought with the planet-altering emissions of modern civilization, the green transformation must be speeded up. Tick, tick, tick.
ABSTRACT OF METHANE LEAK STUDY
The net climate impact of gas and coal life-cycle emissions are highly dependent on methane leakage. Every molecule of methane leaked alters the climate advantage because methane warms the planet significantly more than CO2 over its decade-long lifetime. We find that global gas systems that leak over 4.7% of their methane (when considering a 20-year timeframe) or 7.6% (when considering a 100-year timeframe) are on par with life-cycle coal emissions from methane leaking coal mines. The net climate impact from coal is also influenced by SO2 emissions, which react to form sulfate aerosols that mask warming. We run scenarios that combine varying methane leakage rates from coal and gas with low to high SO2 emissions based on coal sulfur content, flue gas scrubber efficiency, and sulfate aerosol global warming potentials. The methane and SO2 co-emitted with CO2 alter the emissions parity between gas and coal. We estimate that a gas system leakage rate as low as 0.2% is on par with coal, assuming 1.5% sulfur coal that is scrubbed at a 90% efficiency with no coal mine methane when considering climate effects over a 20-year timeframe. Recent aerial measurement surveys of US oil and gas production basins find wide-ranging natural gas leak rates 0.65% to 66.2%, with similar leakage rates detected worldwide. These numerous super-emitting gas systems being detected globally underscore the need to accelerate methane emissions detection, accounting, and management practices to certify that gas assets are less emissions intensive than coal.
