GLOBAL WARMING: The Potentially Catastrophic Gas is Methane, Not Carbon Dioxide

I've long been paranoid about methane, which I consider to be more dangerous for the future of Humanity than carbon dioxide.  Much of my thinking came together when I wrote SIMPLE SOLUTIONS for Planet Earth.  On 4 and 5 September 2008 I had a two part posting on this gas in the 15 part series on THE VENUS SYNDROME, a book I am writing.    These are shown here for completeness.  You can skip them and just move on to the analysis after the asterisk line.        

THERE IS SOMETHING ABOUT METHANE (Part 10)

The chemical nature of this book has thus far mostly dealt with hydrogen, oxygen and carbon, including carbon dioxide, CO2. The simplest fossil fuel is a gas, methane (CH4). Natural gas is mostly methane. When cows flatulate and burp, methane is produced as the primary gas. In fact, a State of California study reported that dairies were the number one source of San Joaquin Valley smog. Not necessarily tongue in check, with the respect to the Kyoto Protocol, it was suggested that reducing methane production made more economic sense than trying to limit carbon dioxide. Then there is the obvious uncontrollable: when forests decay, methane is naturally formed; when trees grow, they also produce methane. It’s really not all that easy to reduce the production of methane.

As a combination series of one carbon and two molecules of hydrogen are added to the compound, the gas becomes liquid, then a solid. Gasoline is essentially the liquid portion of this CH2 chain. All fossil fuels, when burned in air, produce CO2 and heat, plus, depending on the combustion temperature, nitrogen compounds, as the atmosphere is 78% nitrogen. If there are contaminants, such as sulfur, in the fuel, also produced are oxides of sulfur, both of which can form acid rain.

While carbon dioxide is the current major target to combat global warming, most people don’t know that one molecule of methane is 20 to 62 times (depending on whether you compare on a molecular weight, mass, or whatever basis, and are able to include airborne lifetime) worse than one molecule of carbon dioxide in warming the Earth. The Report of the Methane Advisory Committee on Methane Hydrate Issues and Opportunities, a U.S. Department of Energy panel, says that methane is 23 times more effective at warming than an equivalent volume of carbon dioxide over a 100 year lifetime. However, methane is 62 times more powerful as a greenhouse gas over a 20 year period when there is an excess of this gas in the atmosphere. Further, if the infusion of methane is rapid, there would be very dangerous positive climatic feedback. This is the basis of The Venus Syndrome, my attempt to provide a two by four solution to influence decision-makers about the carbon tax.

In 1859 John Tyndall of Ireland showed that methane was like a plank of wood with regards to allowing heat rays to pass. As recently as 1948, though, methane was not even measured in the atmosphere because it was deemed as insignificant. Then in 1971 an authoritative study of climate ignored methane because it had “no direct effects on the climate or the biosphere.” In 1980 V. Ram Ramanathan, when he was with NASA, published a paper surmising that 40% of the total warming could be from the insignificant miscellaneous gases such as methane, nitrous oxide, ozone and CFCs. This led to CFCs being targeted as the culprit for the ozone hole and nitrogen and sulfur oxides as bad for smog and acid rain. But no one really took methane seriously, even when ice cores from Greenland and Antarctica revealed that methane, too, had risen and fallen in step with global temperatures.

My interest in methane actually started in 1979 when I served as the staff director in the U.S. Senate for the Hard Minerals Act, which formalized the national seabed mining program. I participated in interminable gatherings of the Law of Sea Treaty, and note that a quarter century after passage of the bill that the U.S. has not yet signed on, mostly because industry thinks doing so would unduly penalize American companies. If this sounds familiar, yes, the Kyoto Protocol on global climate warming is yet another treaty we have refused to sign because the private sector said no.

The Marine Minerals Technology Center of the Hawaii Natural Energy Institute, funded by the U.S. Department of Interior, served as the leading academic R&D organization of its type in the Pacific. Work on strategic metals languished, partly because of American attitudes and the unfavorable economics of such a venture, but the effort has recently picked up because of marine methane hydrates (MMH)

One of the resources at the bottom of the sea is MMH. In 1991, I joined a group of ocean experts in Berlin to write a book, entitled, Use and Misuse of the Ocean. I served on the chapter dealing with offshore hydrocarbons, chaired by Peter J. Cook, who at that time directed the British Geological Survey. We came up with a wild guess that the “marine gas hydrate layers could contain about twice as much reduced carbon as all other fossil-fuel reservoirs.” In reality, the potential amount of energy forecasted in the literature varied by at least two orders of magnitude, so the true amount remains a huge unknown. It was further noted that freshwater was tied up in these clathrates (or gas hydrates), providing a double benefit to society. We did not mention the double-edged sword danger of this methane regarding global warming, mostly because we then were unaware of the effect.

More recently, the International Center for Climate and Society at the University of Hawaii, a sister unit of the International Pacific Research Center (IPRC, a joint U.S.-Japan alliance, located on the fourth floor of the Pacific Ocean Science and Technology building, where I have been enjoying a favorable corner office for more than 6 years now), has partnered with various academic and research organizations in Alaska to take a closer look at the energy and environmental implications of MMH. Also, too, researchers in the Oceanography Department have refined their observation of the ocean, and have measured the omnipresence of methane, in certain locales to be at supersaturation.

These MMH—methane locked in ice at the sea bottom—are in dynamic equilibrium with the ocean. One cubic meter of fully saturated MMH contains 164 cubic meters of methane (at standard temperature and pressure) and 0.87 cubic meters of water. These hydrates are less dense than seawater, so, if they are somehow jiggled loose, say by an undersea earthquake or volcanic eruption, they rise to the surface. After all, ice and gases only go up when in water. How did they get there? When marine life dies, it descends to the bottom of the ocean. Bacterial degradation of organic matter in low oxygen environments produces methane, which under cold, deep ocean conditions are latticed into ice, and trapped there as long as conditions do not change. If the climate warms enough, then the forcing function will ultimately release methane, which, if not biologically consumed, will make its way to the atmosphere.

Some of the public releases on this subject have been almost inflammatory, so I will attempt to be circumspect. Part 11 will summarize the current state of thinking regarding the potential danger of methane in global climate warming.

And here is the second posting:

JUST HOW DANGEROUS IS METHANE (Part 11)

To recap, methane is most of the energy in natural gas, is the simplest hydrocarbon, has one carbon and four hydrogen atoms—CH4—and can be utilized to cook food, power a car and be converted into ammonia (NH4), the base from which fertilizer is produced. A cow produces this gas, with carbon dioxide; decaying woody material decomposes mostly into carbon dioxide, but also methane; and the globe is warmed by its presence in the atmosphere. In fact, it is from 20 to 62 times more dangerous than carbon dioxide in causing the Greenhouse Effect, depending on which reference you use and the parameters of consideration. Of course, nitrogen dioxide has a global warming potential (GWP) of 296—where carbon dioxide is 1—hydrofluorocarbon HFC-23 is rated 12,000, trifluoromethyl sulfur pentafluoride is 18,000 and sulfur hexafluoride, used as a high voltage insulator, has a GWP of 22,200. Thankfully, there are only trace amounts of those gases in the air. CO2 is needed by plants as we need oxygen, and, all in all, is a reasonably benign gas. It’s just that we produce so much of it. Well, actually, fossil fuel burning is responsible only for 14%--nature is responsible for the rest.

David Archer of the University of Chicago has written a series of papers dealing with MMH and anthropogenic climate change. Part of the following includes some of his writings.

The worst mass extinction in history, killing off 95% of all marine species and 70% of terrestrial life, occurred 251 million years ago, according to Gregory Ryskin of Northwestern University. Methane from bacterial decay or from frozen methane hydrates, stimulated by a meteorite impact, earthquake or volcano, could have triggered a catastrophic eruption of methane gas. Ryskin calculated that the energy liberated could have been 10,000 times greater than the world’s entire nuclear weapons stockpile. He did say he had no proof and it was just his hypothesis. More recent evidence shows that an asteroid crashing off Australia might have triggered the event.

In January 2005, two teams of scientists, from Curtin University of Technology in Perth, Australia, and the University of Washington, reported that the “Great Dying,” 250 million years ago, was caused by volcanic eruptions, which caused atmospheric changes. Plus, this all took place over as much as 10 million years. While the volcanic gas was mostly carbon dioxide, there was also speculation that large stores of methane gas frozen on the ocean floor might have been released to trigger runaway greenhouse warming. Clearly, something happened a quarter billion years ago.

In 2000, Nature reported on “Methane Linked to Mass Extinctions,” when a violent explosion of methane gas from the ocean floor 183 million years ago killed off 80% of some deep-sea species. The article expressed particular concern about drilling for marine methane and the harm that would cause.

The Science Daily reported on December 12, 2001, “Methane Explosion Warmed the Prehistoric Earth, Possible Again.” There was another abrupt warming 55 million years ago, caused by the sudden release from the ocean of frozen deposits of methane. “The massive perturbation to global climate and the carbon cycle during the Paleocene/Eocene Thermal Maximum may have been forced by a catastrophic release of methane gas from hydrate deposits on the continental slope,” said Gavin Schmidt and Drew Shindell of the Goddard Institute for Space Studies. Movement of continental plates may have initiated the release. Ocean temperatures soared by up to 13 degrees Fahrenheit (7 °C), within 1,000 years, by some estimates, but lasting 100,000 years. More than half of deep sea species died. However, it was also reported that primates (apes) suddenly appeared.

There was a puzzling period only 3 to 4 million years ago when carbon dioxide and methane were in the atmosphere at about the same concentration as today, but the temperature was 3 °C (5.4 °F) hotter and sea level 25 meters (82 feet) higher. There was something about the El Nino and the ocean that triggered the warming.

Around 8,000 years ago, the Storegga submarine landslide occurred on the Norwegian continental margin, caused, most probably, by methane hydrate destabilization. While global warming was not a consequence, this landslide did cause a tsunami (sea wave), and is a link to the next chapter on “Six Hours to Seattle.”

To recap, a carbon dioxide atmospheric composition of 380 parts per million and methane of 1.8 parts per million means that there are about 200 times more CO2 than CH4 in the air. However, CH4 is 20 times more dangerous than CO2, so, the effectiveness factor with respect to global warming of CO2 is about 10 times greater. However, Drew Shindell believes that methane is underestimated in the above comparison because it is a reactive gas, unlike carbon dioxide, and, instead of accounting for one-sixth of the total effect of well-mixed greenhouse gases on warming, should be one-third, or twice that currently utilized in climate change models. Shindell’s colleague at GISS, Gavin Schmidt, has said that, under inflated concentration conditions, the methane can linger for hundreds of years, much longer than the decade normally expected.

In a parallel paper regarding methane from wetlands, Shindell says it another way: “Methane increases have contributed about 0.7W/m2 to global radiative forcing since preindustrial times (0.5 W/ W/m2 directly, plus an additional 0.2 Wm2 indirectly via tropospheric ozone and stratospheric water vapor), roughly one-half the forcing from CO2.” Clearly, methane is important.

The literature reports that the oceans release only 10 tons of methane per year. Termites produce 40 tons/year, cattle 60 tons/yr, rice paddies 70 tons/yr and wetlands 115 tons/yr. But no one really knows how much methane is coming from the seas.

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All the above occurred 14 years ago.  Of course carbon dioxide is a threat to Humanity, and we should do a lot more to remediate the looming problem of climate warming.  But is methane another gas we should control?  

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  Actually, not much can be done because much of this gas is produced in nature when biomass degrades, cows and other animals flatulate and the tundra emits.
• Sure we could stop growing cattle, but there is little chance for that to occur in timely fashion.  And anyway, the contribution of methane from all animals will not pose a mortal threat.
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  The problem with methane is that there is so much of it in methane clathrates at the bottom of the sea and tundra, particularly close to coastlines, that the sudden release of these deposits into the atmosphere can cause an extinction event in a very short timeframe.
• The greatest danger is along the Ring of Fire around the Pacific Ocean where methane resources rest in close proximity to volcanic eruptions and earthquakes.

During this 14-year period when I first posted on this ultimate decimation research has only strengthened the potential.  For example, from Jessika Trancik of MIT:

Let’s say a factory releases a ton of methane and a ton of CO2 into the atmosphere today. The methane immediately begins to trap a lot of heat—at least 100 times as much as the CO2. But the methane starts to break down and leave the atmosphere relatively quickly. As more time goes by, and as more of that original ton of methane disappears, the steady warming effect of the CO2 slowly closes the gap. Over 20 years, the methane would trap about 80 times as much heat as the CO2. Over 100 years, that original ton of methane would trap about 25 times as much heat as the ton of CO2.

Further

The EPA, for example, says methane is 25 times as potent as CO2, which is the 100-year statistic.1  Why this number, when methane is far more damaging in the short term? In part, Trancik says, it was an “accident of history.” Decades ago, when scientists began to tackle the complicated task of comparing different greenhouse gases, most climate projections were looking out to the year 2100—about 100 years in the future.

While there is already an alarming amount of methane in our atmosphere, the true danger is not what is presently there, nor what industry and the environment can naturally add over time, it has to do with how we process growing evidence to prevent a possible extinction event.

For one, we need to think how serious methane can be over a shorter time frame, like, say 30 years, which means that molecule against molecule, methane is 75 times worse than carbon dioxide.  The Venus Syndrome, my take on a worst case scenario, has almost nothing to do with normal methane emissions.  What if something more cataclysmic occurs, as might have happened in previous extinction events in geological time?

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  If the emission of methane from industry, forests, the tundra and coastlines are exacerbated by that so called clathrate gun hypothesis, or a sudden release of methane along, say, the Ring of Fire,  all the damage would happen in a relatively short timeframe when methane is 100 times more potent than carbon dioxide.

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  How much energy is stored in these methane clathrate deposits?  As the first posting above shows in RED, this could be twice the amount of all fossil fuel reserves on land.  14 years ago, this was a wild-eyed guess by our editorial group.  This now appears to be an accepted fact, as indicated by NOAA.

When it comes to carbon dioxide, we do have solutions to prevent disaster.  Public will is lacking, and very little is actually being accomplished today except for the alarm of scientists.  But this problem can be solved.

I have stopped writing The Venus Syndrome because I cannot find any viable answer to the Clathrate Gun Hypothesis.  This has probably happened in our geological history, but the only solace I can proffer to you is that this will almost surely not occur for another hundred million years or so, if ever.  So expunge this prospect from your memory, and worry about more logical endings.

Hate my returning to calamities and deaths, so I'll attempt to ameliorate the mood with three animal videos:

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