Methane’s Contribution to Global Warming Is Worse than You Thought

It seems we've been "fudging the numbers" in a sense, when comparing the global warming potential of methane to CO2. When global warming potential (GWP) of a gas is calculated, a time frame is assumed. The IPCC decided to use a 100 year time frame.

With a 100 year time frame methane heats up the planet 21 times as much as CO2. The problem with that assumption is that we don't have 100 years. A 20 year time frame would be much more realistic, given the urgency of climate crisis. With a 20 year time frame...

... any CH4 released today is at least 56 times more heat-trapping than a molecule of C02 also released today. And because of the way it reacts in the atmosphere, the number is probably even higher, according to research conducted by  Drew Shindell , a scientist at NASA’s Goddard Space Center. [emphasis mine]


What if we were to use the IPCC’s 20-year comparison instead of its 100-year comparison? For starters, it would force us to get much more serious about tackling  the sources of methane emissions. Here in the US, the top methane sources are the decomposition of wastes in landfills, agriculture (from ruminant digestion), and leaks from natural gas drilling and transmission. A new emphasis on methane would require us to get smarter about capturing methane at landfills, reduce the market incentives that encourage Americans’ meat-heavy diets, and ensure that methane isn’t leaking from fracking operations.

But beyond the policy specifics, adopting the 20-year global warming potential comparisons would be useful for changing how we think about climate change.

And we appear to be approaching some irrevocable tipping points that will create powerful negative feedback loops, the most worrisome being  the release of methane  stores at the bottom of the ocean and locked into sub-Arctic permafrost.

Image from Arctic Methane Release Tipping Point Diagram
With 56 times as much warming as CO2 in mind, we'd take this feedback more seriously.

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Replies to This Discussion

The people in power, motivated as they are by the profit motive will continue to deny climate change and human's involvement in its increase. I wonder how the children of the Deniers think about these matters? Do you suppose even a small percentage of Denier's offspring will disagree with their Denier Parents? Even if they do disagree, we have far too little time to experience a shift in thinking of the Money Mongers. 

Woods Hole scientists call for research on the tipping point for catastrophic permafrost melting.

Top Scientist — Threat of Catastrophic Permafrost Thaw is “Real and...

A 2 C global warming threshold is generally thought to be the point at which enough of the Arctic permafrost will go into catastrophic destabilization, to result in a global warming amplifying feedback that then thaws all or most of the rest.

The problem is we’ve already emitted enough CO2, methane and other greenhouse gasses to warm the Earth by 2-4 degrees Celsius long term and by around 1.4 to 1.9 degrees Celsius this Century. 

Dr. Holmes’ and his Woods Hole colleagues are calling for a focused effort to more accurately nail down that tipping point. To give us a better idea how close we really are ...

... there may be some risk that enough of the store could become unstable at lesser levels of warming — crossing the tipping point sooner than expected.

Are large Siberian fires … indicative that the Arctic permafrost carbon stores are nearing a critical tipping? [text order altered]

This news is disturbing, insofar as it's generally agreed we've already locked ourselves into more than 2°C warming with fossil fuel infrastructure investments. Japan is helping many countries build even more coal plants, a new tar sands site is starting in the US, and a bill encouraging widespread logging in US National Forests has passed the House. <groan> Is spiraling catastrophic heating just a matter of decades? Have we already guaranteed our doom by the end of this century or early next?

Yesterday a large portion of the Arctic Ocean under which methane lies had an air temperature 20°C above normal for this time of year.

Study of pingos (ice mounds) discovered off the shore of the Sibera, near Yamal where land based pingos erupted to create blowholes, shows they're also caused by melting permafrost. Two undersea pingos were studied by radar. One was leaking copious amounts of recently-generated methane.

Methane Bubbling up and melting down

This is a land-based pingo.

At sea, the mounds, measuring 70m-100m across and nicknamed pingos, are believed to be formed when is methane released from soil that has been thawed by warming ocean water. On shore, such mounds are generally smaller and formed in a slightly different manner, but both may be the precursor to sinkholes, which form after methane makes its way to the surface and either dissipates slowly into the atmosphere or blasts out. [emphasis mine]

Sudden methane releases from pingos might explain the extra high outlier methane readings periodically recorded. Of course we wouldn't be aware of such events unless a ship or plane happened to be nearby and recording it.

This map shows the undersea pingo locations.

Pingo 2 designates

One very large group of pingo-like formations,  the largest of which was up to 1,000 meters in diameter, did not have noteworthy concentrations of methane in the seafloor sediments at its top.

Pingo 1 designates

... a smaller one [that] had very high concentrations of methane in the sediment, greater than 120,000 parts per million.

Remember those weird Siberian craters? Scientists say they may have...

Washington Post journalist Chris Mooney goes out of his way to minimize their significance. For example, since the study authors say it's not a "doomsday climate scenario", therefore it's"... not anything systematic or large scale enough to suggest a climate worry."

“I think those pingos are zones of focused discharge, but the total input of methane coming from pingos is not so significant,” says Serov.

Even if the total input of methane from pingos NOW isn't significant, why jump to "not a climate worry" going forward? Oh right, we should assume the Kara Sea won't get warmer.

On the other hand, Mooney says,

The worry that there could be a climatically significant methane “feedback”... relies on a large number of assumptions and contingencies.

So we discount the danger of positive methane hydrate release feedback because it's based on assumptions, and we discount worry about future methane release from undersea pingos based on an assumption.

image source

Researchers decipher the history of paleoclimate change with surpri...

Analysis of an ocean floor sediment core from the Santa Barbara Basin shows that melting methane hydrates caused a 7°F to 9°F rise in 50 years around 630,000 years ago. A similar process may already have begun.

Laminations in this sediment core

provide a high-fidelity record

of paleoclimate change history.

… a shift from a glacial to an interglacial climate that began about 630,000 years ago. …, the initial shift required only 50 years. Called a deglacial episode because of its association with the melting of large Northern Hemisphere ice sheets, this interval illustrates the extreme sensitivity to change of the Earth's climate system.

"Of the 13 degree Fahrenheit total change, a shift of 7 to 9 degrees occurred almost immediately right at the beginning."

What process can possibly push the Earth's climate so fast from a glacial to an interglacial state? The researchers may have discovered the answer based on the core's geochemical record: The warming associated with the major climatic shift was accompanied by simultaneous releases of methane—a potent greenhouse gas.

"This particular episode of climate change is closely associated with instability that caused the release of methane from gas hydrates at the ocean floor," Kennett said. "These frozen forms of methane melt when temperatures rise or pressure decreases. Changes in sea level affect the stability of gas hydrates and water temperature even more so.

"The clear synchronism of this rapid warming and the onset of the destabilization of gas hydrates is important," Kennett concluded. "It suggests that methane hydrate instability and the warming are somehow linked,…

Kennett said that one of the current worries about modern global warming is that the increase in ocean temperatures will destabilize methane hydrates located at relatively shallow depths on the ocean margin, in turn causing positive feedbacks that reinforce the global warming. In fact, this appears already to be occurring in the ocean.

Recent research by others indicates that methane hydrates off the coast of Washington, Oregon and British Columbia are destabilizing in response to a small increase in bottom water temperatures (only 0.3 degrees Celsius) during the past 44 years. This is producing methane gas plumes that billow upward from the ocean floor.

Global Warming’s Terrifying New Chemistry

US really wrong is about methane emissions -Bill McKibben.

Between 2002 and 2014, the data showed that US methane emissions increased by more than 30 percent, accounting for 30 to 60 percent of an enormous spike in methane in the entire planet’s atmosphere.

The EPA insisted this wasn’t happening, that methane was on the decline just like CO2. But it turns out, as some scientists have been insisting for years, the EPA was wrong. Really  wrong. This error is the rough equivalent of the New York Stock Exchange announcing tomorrow that the Dow Jones isn’t really at 17,000: Its computer program has been making a mistake, and your index fund actually stands at 11,000.

These leaks are big enough to wipe out a large share of the gains from the Obama administration’s work on climate change—all those closed coal mines and fuel-efficient cars. In fact, it’s even possible that America’s contribution to global warming increased during the Obama years.

It’s a disaster—and one that seems set to spread.

… the core problem …is the rapid spread of fracking.

Instead of peaking in 2007 and then trending downward, as the EPA has maintained, our combined emissions of methane and carbon dioxide have gone steadily and sharply up during the Obama years, Howarth says. We closed coal plants and opened methane leaks, and the result is that things have gotten worse.

… today, the State Department provides “assistance” with fracking to dozens of countries around the world, from Cambodia to Papua New Guinea.

If the State Department has its way, then in a few years Harvard’s satellites will be measuring gushers of methane from every direction. [emphasis mine]

NOAA methane figures show accelerating curve.

Here's the last few years up close.

February 2016:     1840.6 ppb
February 2015:     1832.4 ppb
Last updated: May 5, 2016

Some worry that positive feedbacks have begun.

Some things are certain, we are too late with too little ; the future will be nothing like the past; the only constant is change. 

Trite! I know!  I can't find anything positive to say. 

OK! Given this reality, ... I'm glad I am 80 years old. 

I appreciate having a few people to talk to about what's happening. Were I all alone, it would be harder to keep going. Even most well informed people don't keep up to date on new developments, much less "process" the information emotionally. Thanks.

the implications for climate policy of staying “well below 2°C” — let alone aiming for 1.5°C — are simply unprecedented. They haven’t been thought through and internalized by even very well-informed people. [emphasis mine]

Almost Everything You Know About Climate Change Solutions Is Outdat...

image source

Record Arctic melting may be destabilizing East Siberian Ice Shelf's methane hydrates.

Recently, an abrupt methane release from the Arctic Ocean seafloor did enter the atmosphere over the East Siberian Sea, showing up with levels as high as 2578 ppb (at 586 mb on May 15, 2016, pm, see image below). Such abrupt releases are indications that methane hydrates are destabilizing and are warnings that climate catastrophe is waiting to happen.

Further Confirmation Of Arctic Sea Ice Dramatic Fall

Scientists have monitored greenhouse gas methane – once frozen on the sea bed – bubbling up to the surface at an alarming rate.

According to one study published in the journal Nature by Professor Wadhams and others, this could produce an average rise in global temperature of 0.6 degrees Celsius in just five years.

Arctic could become ice-free for first time in more than 100,000 ye...

I assume this means 0.6° Celsius rise every five years from methane hydrate, not that it would rise 0.6° in the first five years and then mysteriously stop rising. That acceleration is the most frightening prospect, not just one "very, very serious upward jerk". In fact it seems reasonable that the rate would gradually increase over time.

I should point out that Dr Wadham's prediction that the Arctic could be free of sea ice this year or next is not supported by Dr Peter Gleick or Professor Jennifer Francis. But remember scientists like Wadhams who study the Arctic first hand have consistently warned that climate models are too conservative, while model makers disagreed (and were proved wrong year after year).

Peter Gleick does say that

“ … the changes in the Arctic presage dramatic fundamental changes in climate throughout the globe.”

“We're on a runaway train, scientists are blowing the whistle, but politicians are still shovelling coal into the engine.”




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