There have been five mass extinction events on plant Earth. The sixth mass extinction event is currently underway, i.e., the Holocene extinction, the first that is the result of human activity.

The Permian–Triassic extinction, which occurred 251 million years ago, is considered the worst in all history because around 96% of species were lost. “The Great Dying” was caused by large amounts of methane. Methane-spewing Microbe Blamed in Earth’s Worst Mass Extinction. “This dramatically heated up the climate and fundamentally altered the chemistry of the oceans by driving up acid levels, causing unlivable conditions for many species.”

The Arctic landscape stores one of the largest natural reservoirs of organic carbon in the world in its frozen soils. But once thawed, soil microbes in the permafrost can turn that carbon into the greenhouse gases carbon dioxide and methane, which then enter into the atmosphere and contribute to climate warming. Unexpected future boost of methane possible from Arctic permafrost:

“The mechanism of abrupt thaw and thermokarst lake formation matters a lot for the permafrost-carbon feedback this century,” said first author Katey Walter Anthony at the University of Alaska, Fairbanks, who led the project that was part of NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE), a ten-year program to understand climate change effects on the Arctic. “We don’t have to wait 200 or 300 years to get these large releases of permafrost carbon. Within my lifetime, my children’s lifetime, it should be ramping up. It’s already happening but it’s not happening at a really fast rate right now, but within a few decades, it should peak.”

The results were published in Nature Communications.

Using a combination of computer models and field measurements, Walter Anthony and an international team of U.S. and German researchers found that abrupt thawing more than doubles previous estimates of permafrost-derived greenhouse warming. They found that the abrupt thaw process increases the release of ancient carbon stored in the soil 125 to 190 percent compared to gradual thawing alone. What’s more, they found that in future warming scenarios defined by the Intergovernmental Panel on Climate Change, abrupt thawing was as important under the moderate reduction of emissions scenario as it was under the extreme business-as-usual scenario. This means that even in the scenario where humans reduced their global carbon emissions, large methane releases from abrupt thawing are still likely to occur.

As greenhouse gases go, methane gets less attention than carbon dioxide, but it is a key contributor to climate change. David Roberts writes at Vox, Fracking may be a bigger climate problem than we thought:

In the real world, though, the news about methane is bad and getting worse. It turns out that a mysterious recent spike in global methane levels that’s putting climate targets at risk may be coming from US oil and gas fracking. If that’s true, it’s bad news, because there’s lots more shale gas development in the pipeline and the Trump administration is expected to release a proposed rule Thursday rolling back regulations on the industry, per the New York Times.

That’s right, the climate change denying, science denying Trump administration’s E.P.A. will Roll Back Regulations on Methane, a Potent Greenhouse Gas:

The Trump administration laid out on Thursday a far-reaching plan to cut back on the regulation of methane emissions, a major contributor to climate change.

The Environmental Protection Agency, in its proposed rule, aims to eliminate federal requirements that oil and gas companies install technology to detect and fix methane leaks from wells, pipelines and storage facilities. It will also reopen the question of whether the E.P.A. even has the legal authority to regulate methane as a pollutant.

What is truly insane about this new Trump administration policy:

The rollback is particularly notable because major energy companies have, in fact, spoken out against it — joining the ranks of automakers, electric utilities and other industrial giants that have opposed other administration initiatives to dismantle climate-change and environmental rules.

The weakening of the methane standard is the latest in a historic march of environmental-policy rollbacks by the Trump administration designed to loosen regulations on industry.

The mysterious spike in atmospheric methane may lead to America’s doorstep

Global methane emissions rose steeply in the last decades of the 20th century and then leveled off. But around 2006, they started heading up again. Why? What was the source? Scientists were baffled. (Jonathan Mingle wrote a great story for Undark on scientists’ search for answers.)

There are two broad sources of methane emissions: biogenic (plant and animal-based) and fossil fuel production. The former is mainly about agriculture (cow burps, pig poop, rotting organic waste) and tropical wetlands. As for the latter, methane is leaked or deliberately “flared” (burned off) at virtually every stage of fossil fuel production and transport, a problem that is notoriously bad for fracked shale gas and tight oil.

A few studies, including a major one in the journal Science in 2016, largely traced the recent spike in methane to biogenic sources, mainly because recent atmospheric methane has been “lighter,” depleted of its heavier carbon stable isotope (13C). Generally speaking, fossil fuel production produces heavier methane and biogenic sources produce lighter methane, so researchers have taken the trend as an indication that the recent spike is mostly biogenic in origin.

But it was a perplexing finding, one that the Science authors characterized as “unexpected, given the recent boom in unconventional gas production and reported resurgence in coal mining and the Asian economy.” If you see a big boom in fossil fuel production happening alongside a big spike in methane, you might expect to find the two connected.

In a new paper released in Biogeosciences, Robert Howarth of Cornell University has proposed a solution to the riddle.

Howarth is a familiar name to those who have followed methane debates over the years. He and colleagues at Cornell have been arguing for years that natural gas methane emissions are much higher than the government estimates or the industry admits, high enough to wipe out its supposed climate advantage over coal. That is a controversial position, to say the least. (Estimates of methane leakage vary widely, but Howarth’s is at the very top end.)

In his latest paper, Howarth is making a different point, springing from two facts he says previous studies have overlooked.

Fig_mt_46

First, 63 percent of the total increase in global natural gas production in the 21st century has come from shale gas. And second, shale gas production using modern hydrofracturing techniques tends to produce lighter methane than conventional natural gas drilling.

Howarth finds that if the lighter methane of shale gas production is explicitly accounted for, “shale-gas production in North America over the past decade may have contributed more than half of all of the increased [methane] emissions from fossil fuels globally and approximately one-third of the total increased emissions from all sources globally over the past decade.”

Since 89 percent of the shale gas production comes from the US (Canada produced the rest), that’s a whole lot of accelerated global warming tracing right back to America’s front door.

It is worth emphasizing that this is only one paper in a very active field of research, from a controversial source, and it is sure to be debated and contested in coming years. But if it is right, or even only half right, it is bad news.

All signs point toward increased methane in coming years

If increased methane from shale gas is helping drive the spike in global methane emissions, the climate is in serious trouble, because there is every indication that shale gas emissions are higher than generally estimated and set to keep rising.

First, six years of intensive research from the Environmental Defense Fund has shown that methane emissions from US oil and natural gas production are as much as 60 percent higher than government estimates. This recent paper in Science summarizes: “Methane emissions of this magnitude, per unit of natural gas consumed, produce radiative forcing over a 20-year time horizon comparable to the CO2 from natural gas combustion.” Getting natural gas out of the ground and to its final destination releases as much methane as burning it — which, whether or not it makes gas “worse than coal,” makes it pretty bad.

Meanwhile, as Jennifer Dlouhy reports for Bloomberg, “the Trump administration is readying a plan to end direct federal regulation of methane leaks from oil and gas facilities, even as some energy companies insist they don’t want the relief.” The high-profile energy companies, the ones with large operations and lots of exposure to public opinion, rightly see this as a terrible idea. It makes them look like climate villains; it increases their exposure to climate risk and future policy shifts; it makes investors uncertain and hesitant. Oh, and it exacerbates climate change.

But the little companies, with lots of small, leaky wells scattered about, don’t want to be forced to clean them up; in many cases, being forced to run clean would destroy the economics and shut down the wells.

And Trump is personally dedicated to reversing everything Obama did, so … methane-wise, it’s back to the Wild West.

Third and most disturbingly, the US appears to be in the early stages of a massive fracking infrastructure buildout. A recent report from Food & Water Watch (FWW) charted this buildout, identifying “more than 700 fracked gas infrastructure projects that have been recently built or proposed for development.”

There are liquid natural gas export terminals: “In 2018, there were only three active LNG export facilities in the U.S., but 22 more were either being built or approved for construction, and an additional 22 were pending federal review by the end of the year.” There is the plastics industry, with “more than $202 billion slated for investment in ​333 new or expanded facilities.” And there is the electricity sector, with “plans to develop ​364 new fracked gas-fired plants​ by 2022.”

Despite escalating concerns over the climate impact of natural gas and signs that it is flagging somewhat in the electricity sector, the industry seems poised for enormous expansion. That is wildly irresponsible in the face of the widely agreed upon (by everyone but Republicans) need to reach net-zero greenhouse gas emissions, in the US and globally, by midcentury.

With jurisdiction over the rapidly metastasizing shale gas industry, the US has direct control over one of the biggest and fastest-growing sources of potent, fast-acting methane. That means it also has, within its reach, the ability to make early and substantial progress on climate change.

Several Democratic candidates have proposed ending fracking on public lands; only a few (Jay Inslee, Bernie Sanders, and Tom Steyer) have explicitly proposed pursuing a national ban. That hasn’t been a top-tier policy dispute yet, but as scientists make the grim effects of fracking clearer and clearer, it’s going to become one.

Popular Mechanics adds (excerpts) (h/t graphic):

The Environmental Protection Agency (EPA) announced today that it will roll back Obama-era regulations on methane gas, a powerful greenhouse gas … The Trump administration argues that the EPA does not have the authority to regulate methane gas under the Clean Air Act. But the move goes against the recommendation of some major players in the oil and natural gas industry, such as Shell, BP, and Exxon, which supported the 2016 regulations and have recently made public their commitment to curbing methane gas emissions.

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The gas is also a significant contributor to climate change. In 2017, methane accounted for roughly 10 percent of all human-driven greenhouse gas emissions in the U.S., according to the EPA. While it isn’t the most abundant greenhouse gas in the atmosphere, it is among the most powerful.

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According to the EPA, roughly 50 to 65 percent of U.S. methane emissions are related to human activity, while around 30 percent of human-related methane emissions are released by the natural gas and petroleum industry.

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Of all the greenhouse gases, methane is one of the most potent because of its ability to efficiently absorb heat in Earth’s atmosphere. Studies have shown that, over a 20-year period, a kilogram of methane warms the planet as much as 80 times more than a kilogram of carbon dioxide.

Methane lasts for maybe a decade in Earth’s atmosphere before it begins to react with a free radical called hydroxide and turns into carbon dioxide, where it will stay there for centuries.

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Scientists have known for a long time that carbon dioxide heats Earth’s atmosphere and oceans, causing them to expand, but they only recently discovered that short-lived greenhouse gases like methane and CFCs (gases that contain chlorine or fluorine) also spur thermal expansion. In 2017, scientists ran computer simulations that showed thermal expansion caused by methane continues for centuries even after the gas has dissipated from the atmosphere.

So yeah, you friggin’ idiots, let’s not do anything about methane gas and global warming. We are the architects of our own mass extinction event, at the hands of climate science deniers with Obama derangement syndrome.