Is the Risk of Methane Being Greatly Under Underestimated?

Lately, in a strong sign of enormous change brewing in the arctic, methane levels in the region have been spiking to unheard of levels.

The reason is that on the heels of a multi million year and still fast accumulating change upward in earth’s long term atmospheric energy recapture, things are happening below the water’s surface (and in the many fields of (traditionally) near perpetual frost covering much of the northern land of the globe), that are in turn starting to affect what’s happening above the surface.

This is especially true when it comes to the “second” most important greenhouse gas, methane; a gas we may be greatly underestimating in terms of net future impact. And for some pretty key reasons:

Namely, the fact of increasing release of methane from otherwise long frozen deposits that our geologically radical atmospheric alteration is increasingly setting in motion. And the way we currently measure this gas’s importance. That is, based upon current amounts; the fact that more than half of it largely disappears within 10 years; and the fact we can lessen our own emissions which have, at least historically, largely contributed to methane levels’ sudden modern rise.

This current method of assesment that hinges on the fact methane doesn’t last very long, brings up a fundamental problem in assessing methane’s future impact if levels of methane in fact stay high or go higher: That is, the methane gas breaking down is replenished by new methane; and thus future effect estimations based upon most of the current methane in the atmosphere breaking down won’t apply, and total future effect will be greatly underestimated.

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Methane, or CH4, is a potent greenhouse gas – many, many times more effective at absorbing and re-radiating thermal radiation than its more popular cousin CO2.

In terms of earth’s accumulating net energy balance – the phenomenon a little misleadingly but very popularly called “climate change,” CH4 may be considered less critical than CO2. That is, if levels don’t continue to significantly rise.

But at about 1/250th of the current the atmospheric concentration, but perhaps as high as near 200 times the GWPe (or Global Warming Potential equivalent) of CO2 at any one point in time, methane still plays a huge role in the increase in thermal radiation energy recapture in our atmosphere, and the resulting long term earth impacts from it, that in essence constitute this infamous and often misunderstood climate change phenomenon.

Perhaps even more interestingly yet rarely noted, the total percentage increase in atmospheric methane over pre-industrial levels is also much higher than the total percentage increase in Carbon Dioxide from pre industrial levels. (Total concentration of atmospheric methane rose from roughly 750-800 ppb, to just above 1800 –  an increase of around 100%- while concentrations of carbon dioxide rose from roughly 280 or 290 ppm to about 400 – an increase of around 40%.)

Thus the total net effect of modern industrial era increases of methane on earth’s climate shows as a much higher ratio to carbon dioxide than when just the relative total amount of each gas in the atmosphere – which includes all of the gas that reflects pre industrial levels as well, as normally done – is considered.

If the total energy recapturing effect of the increase in trailing methane levels over pre industrial times is considered in relation to the total energy recpaturing effect of the increase in trailing carbon dioxide levels over pre industrial times, the overall impact of each gas is closer than the wide disparity in importance normally attributed to each. (Methane increases are at about a 1:110 ratio to carbon dioxide increases over pre industrial times, and methane is potentially more than 110x as effective per unit of mass, as methane, at recapturing energy than carbon dioxide, although there are limitations concerning how much of this effect is realized at any point given a few considerations briefly referenced below.)

The effect of any unit mass of methane (that’s not replaced), over a longer period is far less, however. For instance, methane is estimated to have only have around 25 times the warming effect of CO2 over a 100 year period. (And about 85 times over a 20 year period.) This is because over a 100 year period methane only exists as methane for a small fraction of the time; and over a 20 year period it still exists as methane a minority of the time, with slightly more than half of it gone after just 10 years.

So since it breaks down somewhat quickly, if we’re trying to gauge the future effect of the gases in the atmosphere right now, it makes sense to use a long time period – such as “100 years,” the most common figure – to estimate methane’s potential future climate change impact; and thus project that impact as much lower than if we didn’t otherwise do this, since most of the gas won’t be methane during the great majority of the period.

But, if methane stays at current levels or goes higher, this doesn’t make any sense: The same amount of methane being projected out over 100 years on the far reduced basic, will instead continue to be in the atmosphere, and thus have an effect many times greater than will be yielded by using the far lower “warming potential” for each gram of methane that, essentially, is largely based upon most of it not existing during that time period.

Modern methane levels, just like carbon dioxide, have also essentially shot straight up in relation to the long term trailing geologic record. And there’s high risk of them not only staying high (making current assessments of methane’s future impact significantly underestimated), but climbing higher still – possibly even exploding higher over a relevant span of time in the near geologic future:

For – and well below the radar of most modern society – methane levels in the arctic have recently been spiking much, much, higher.

And this increasing signal of arctic change, may be starting to tell a rather remarkable story.

Methane, and the Constraint of our Imaginations

Below is an EPA graph that on the left shows methane levels up to the present, dating back about 800,000 years. The right blows up the last .00008 years of the left side of the chart, and shows methane levels from 1950 to 2013.  As can be seen, prior to the industrial revolution and for going on at least near a million years, atmospheric methane levels were never above 800 ppb.

Yet notice on the left of the graph how at the very end of the 800,000 year period, the levels a) essentially shoot straight up, and b) geologically, shoot up by a whopping total amount.

That is, during our modern industrial age – barely a pinprick of even recent geologic time – methane levels have suddenly shot up to more than double the highest average atmospheric concentration earth has seen in close to a million years. (And, if we consider past levels in comparison to today’s, levels have very likely been lower for a lot longer, although harder to directly ascertain since the most reliable source of trailing geologic atmospheric data – ice core sampling from holes drilled “backward” in time down into layers of thick glacial ice – only goes back about 800,000 years.)

That is, methane levels have not just significantly increased, but have gone up by more than an additional 800 ppb increase alone. And lately in the arctic, methane levels have spiked an additional 800 ppb or more further above that.

Methane is nowhere near as long lasting as the other major long lived greenhouse gases. And it breaks down (largely into CO2) over several years. (It takes about 12 years for a quantity of methane to be reduced to around 37% of its original amount.)

Yet it’s an intensely more powerful thermal radiation reabsorbing and reradiating greenhouse gas than carbon dioxide. So the more of the original methane that still exists as such (or that’s simply replaced by new methane) at any one time, the higher its energy capture and re radiation potential (the “trapping” of heat energy that then in turn transfers large amounts back to the earth, ice sheets, oceans, and so on and so on), will be.

In fact, over a 20 year period, the global warming potential per unit mass of methane is, again, somewhere  in the neighborhood of 85 or so times that of carbon dioxide. This means that over 20 years 1000 extra tonnes of methane added to the net amount in the atmosphere can have up to the same energy recapture effect as roughly 85,000 extra tonnes of carbon dioxide added to the net amount in the atmosphere.

It actually gets somewhat more complicated than this, as the more total greenhouse gas in the atmosphere, the more heat energy is trapped all around, including capture of already absorbed and re rediated energy that is re radiated downward (back toward earth) and then re captured and re radiated once again in all directions.

The impact of increased trapped radiation back upon earth’s systems from an increase in total greenhouse gas concentrations also have interacting effects that also impact total net long term energy retention. (For instance, a sufficient increase in trapped radiation will lessen total ice cover, grealy increasing solar absorption. This means more direct warming – heat energy retention – of the physical land, ice and in particular global ocean will occur, less sunlight will be reflected back upward as still short wavelength solar radiation (which essentially isn’t “trapped” or absorbed by greenhouse gases), and far more will ultimately be radiated in medium wavelength, as thermal radiation, and re captured by greenhouses instead.)

But this potentially non linear nature of total net greenhouse gas radiative forcing is also part of why just a few hundred ppm of CO2 and ppb of CH4, and small amounts of a few other lesser gases, are sufficient to keep earth at about 58 degrees on average world wide, instead of all but a lifeless frozen ball of ice averaging 0 degrees; but a doubling of these amounts wouldn’t jack up earth’s average temperature to 116 degrees, which would turn earth into a furnace. This is a gross oversimplification, but it helps show the complication.

(It also helps show how on the flip side, a fairly large increase in those concentrations will, among other things, ultimately likely raise the earth several degrees, depending on feedbacks and other effects, and far more relevantly presents a larger risk range of lower end effects to major if not radical climatic shifting. Although every single possible complication, and multiple invented ones, are grasped at to try and reinforce the archaic, and very much the opposite of Galileo, belief that man can’t much relevantly affect his own global environment here on earth.)

Methane also re radiates certain bands of thermal radiation wavelength, so as more and more methane is present, the increased recapture of energy already trapped by molecules, which would amplify far more quickly from major increases in methane than in the case of carbon dioxide since it’s such a far more potent energy capturing gas, as well as from the atttendant potential limitation of available energy at that wavelength, would tend to cause methane to have a somewhat lower total energy recapture impact than its total warming potential (potential per molecule to absorb and re radiate thermal radiation).

But the bigger point is that even in terms of assessing methane’s overall impact by using the far more finely honed but complex and inexact radiative forcing quotients than the simplistic story told here, higher ongoing amounts of methane in our atmosphere mean a very different and far more powerful story than the one currently told by estimates that are based on current atmospheric methane amounts and the fairly fast breakdown rate of that methane, that thus uses a far lower energy trapping quotient than is likely going to be realized in the atmosphere from total methane concentrations over time.

In other words, if we project the effect of 1800 ppm methane over 100 years, as is commonly done, and use the GWPe wherein most of that 1800 ppm is not methane for the great majority of the time period, the estimated future effect will only be a small fraction of what the real effect on total atmospheric thermal radiation recapture will in fact be if methane levels stay at 1800 (or go higher).: thus meaning for the entirety of that 100 years, it’s all methane. (The molecules being broken down thus being replaced so that the total concentration, and thus energy recapture potential and effect, stays far, far higher.)

For instance, if we use a 20 year GWP for estimating methane’s future global warming impact, the future impact will be considered far higher. Yet even over just a 20 year period a fairly high percentage of any methane originally released into the atmosphere has already broken down.

Knock the measuring period down to about 10 years, and the total heat energy re-capture (or “surface emitted thermal radiation absorption and re-radiation”), potential shoots up far far higher than 85 times the impact, gram for gram, than carbon dioxidem, even if all of it isn’t realized due to multiple capture of methane’s target wavelengths.

In short, when methane is looked at as methane – what it should be looked at in terms of assessing the impact of future atmospheric methane levels over time – the effect is far more profound than when looked at as only a short term gas projected out, based on today’s levels, and with the expectation that most of today’s methane won’t be methane for the great majority of the period:

Which, in turn, is great for assessing the impact of today’s methane levels alone. But it’s potentially the opposite for assessing the actual long term impact of total ongoing atmospheric methane levels and, though harder to project, what’s actually relevant here to gauge the impact of that methane: What methane will be over the next X years, not just what it is this moment.

And, again, as there is more carbon buried as methane in frozen but now beginning to thaw sea floor bottoms than already exists in the entire atmosphere (and many many hundreds of times more than exists as a carbon atom making up part of a molecule of methane), and likely a little over one and a half times that, give or take, on land based permafrost areas (which would emit as both carbon and methane), the issue is not just one of how much our farm raised ruminant animals chew cud, wetlands, landfills, gas leakage or fossil fuel extraction and transport, etc,; but at this point, more predominantly one of the ongoing march of increasing ocean temperatures and melting ice sheets, and the uncertain but potentially huge impact upon otherwise long frozen (i..e, sequestered) methane gas as well as additional carbon.

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Thus, a big increase in methane’s concentrations over time is potentially far more significant – due to the shorter shrift than carbon dioxide that methane usually gets, due to its smaller concentrations, and far shorter realistic lifespan – than might at first appear.

In other words, the average concentration of the gas over trailing time is what ultimately mattered. (Whatever net effect it was; even if most of this energy recapture effect that, along with the geogolically relevant increases in long term greenhouse gases that produce it essentially define the climate change challenge, has, so far gone into changing earth’s future climate impacting systems, and accumulating surface land, ice and ocean energy.)

But what the gas will be in the future, not what today’s gas alone will do, is what matters for the future. And thus average levels of the gas in the future will matter far more than methane effects typically projected based upon today’s levels  and methane’s high breakdown rate.

And this will be even more relevant – perhaps far more so – if there is ever a very large influx into the atmosphere over a shorter, or simply ongoing, period of time, and sufficient to have a fairly powerful short term amplifying heat recapture effect.**** [The reason for this seeming oversight is that climate change has been hard enough to illuminate to the public particularly in the face of sound bite news, and rampant information that as a matter of advocacy simply seeks to try and refute the issue, rather than – mistakes and all, in any random direction as part of the process of evaluating itself – simply try and objectively and dispassionately assess it, or just an extremely poor overall assessment of what risk ranges mean or the fact that that it’s risk ranges, not what will assuredly happen or that can somehow be exactly predicted (nearly impossible as that is) that is relevant to assessing this issue.]****

And, lo and behold — and barely touched on as we focus almost exclusively on air temperature and the enormously mistaken (if not flat out geo-physically ridiculous) “skeptic” idea that for climate change to be “real” or significant means we have to be able to (almost impossibly) predict the exact amount of short term average ambient air change in advance — there’s a fairly extensive risk of just such ongoing high, if not at some point significantly increasing, methane levels.

Given the enormous amounts of methane buried in shallow sea bed areas, as well as the enormous amounts of carbon buried in the northern hemisphere’s vast permafrost – much of which will be emitted as methane when and as our northern permafrost melts, and just as it is slowly starting to do – a large, ongoing and even crescendoing influx of methane over a fairly relevant period of geologic time, is a large possibility; while some ongoing and increasing total methane release from the impact of atmospheric change itself, rather than directly as a result of at this point controllable anthropogenic activities, is very likely.

And the large ongoing methane increase side of this equation is an even stronger possibility if, as many scientists project, there’s a short period of rapid geologic change as a result of the enormous and growing earth energy balance changes currently underway due to a massive and steady input of long lived heat energy trapping gaseous molecules into the atmosphere. Which input in turn – and in just a few hundred years, much of it just in the last 50 or so – has increased current concentrations of carbon dioxide alone to amounts likely not seen on earth in three million or more years.

And in an event of a rapid geologic climate shifting – which could happen at any time but becomes increasingly likely as our oceans continue to warm at a remarkably fast clip, and polar ice cap melt rates at both ends of the earth continue to accelerate – the rapid release of a lot of methane, with its powerful warming potential relative to carbon dioxide, would significantly amplify and extend any climate shifting process, perhaps even fundamentally re-write it.

This is something we’re not quite getting because our imaginations tend to be somewhat constrained by what we’re used to seeing, and we don’t quite integrate what a multi million year change to the long term molecular heat trapping property of the atmosphere, in a remarkably short geologic time period, really means in terms of earth’s shifting energy balance. (And as sites like this – now to nearly 300,000,000 page views, and overwhelming influence – and countless others seek to refute the very idea itself, to perpetuate an ideological, old school belief of non relevant atmospheric impact, under seeming guise of “reason”and an almost non stop onslaught of irrelevant, cherry picked, or issue misconstruing arguments and claims, all with enormous built in rhetoric.)  To us it’s still sort of “abstract.”

Massive change, well after the cause – underlying energy shifts – in what we can later see, won’t be so abstract.