Guess we thought we would all get away with it. That it just wouldn't come to pass. Despite all the inevitability. That it would turn out to be no more than another apocalyptic scare story from those crackpot Earth scientists – the ones who were running around thirty years ago predicting arrival of the next ice age.
Or if it really is inevitable, not in our lifetimes. Or at least, for pity's sake, not until 2070 when we've had our best years and are about ready to depart this mortal coil.
Best of all, that it should be like all those other things you read about in the news that everyone gets so exercised about, but then just seem to dissolve and leave nothing. Nothing happens, then later people seem hardly to remember. The millenium bug, the asteroid that is going to hit, the killer bees. Perhaps avian flu. Things like that. Scary stories that spice life up and cause a big hoo-ha... but ultimately come to zilch.
Like positive feedback cutting in and spiralling climate change - more or less literally - into the stratosphere. Images of millions of tonnes of methane liberated from the sea floor, bubbling up to the surface in great plumes over vast swathes of ocean, making research vessels look like toy boats in some infernal hot tub with the jacuzzi turned up full... Ideas like that.
But of course that all remains incorrigibly hypothetical, because the tipping point has always been w a y over yonder.
If it is not totally mythical. Or so goes the thinking.
Well guess what...?
...No!
Yep.
Afraid so.
Or - if it isn't - it is something never before seen that just happens to bear the most uncanny likeness.
'"We had a hectic finishing of the sampling programme yesterday and this past night," said Dr Gustafsson. "An extensive area of intense methane release was found. At earlier sites we had found elevated levels of dissolved methane. Yesterday, for the first time, we documented a field where the release was so intense that the methane did not have time to dissolve into the seawater but was rising as methane bubbles to the sea surface. These 'methane chimneys' were documented on echo sounder and with seismic [instruments]."
At some locations, methane concentrations reached 100 times background levels. These anomalies have been seen in the East Siberian Sea and the Laptev Sea, covering several tens of thousands of square kilometres, amounting to millions of tons of methane, said Dr Gustafsson. "This may be of the same magnitude as presently estimated from the global ocean," he said. "Nobody knows how many more such areas exist on the extensive East Siberian continental shelves.
"The conventional thought has been that the permafrost 'lid' on the sub-sea sediments on the Siberian shelf should cap and hold the massive reservoirs of shallow methane deposits in place. The growing evidence for release of methane in this inaccessible region may suggest that the permafrost lid is starting to get perforated and thus leak methane... The permafrost now has small holes. We have found elevated levels of methane above the water surface and even more in the water just below. It is obvious that the source is the seabed."'
This is not science fiction. Nor is it the script from some topical TV drama.
It comes from an exclusive called, aptly enough, Exclusive: The Methane time bomb carried by the Independent on 23 September. The quote above is how it covered a rather breathless report by the leader of an international scientific expedition, made direct from the decks of the research vessel immediately it finished sailing the entire length of Russia's north coast.
Arguably this is the most important news story of all time - because it indicates, for the first time ever, a reasonable possibility of the arrival of conditions that will bring life as we know it shortly to an end, (including the two-legged ones - and history too, being an exclusively anthropocentric interest, also, for that matter). As such it deserves detailed examination, so here is a cheat sheet.
What we have here is more or less exactly what is predicted by the positive feedback model. So is that what is going on?
Well there seems to be a strong case in that direction. It would seem to be primary evidence that climate change has now got to such a magnitude that it is causing the melting of permafrost and methane hydrates on a large scale. First, the fit is near perfect. The Arctic as the hotspot for global warming is heating up tremendously – the latest figure is by an astonishing five degrees. The Arctic ice seems to be in terminal retreat with the consequence that yet more energy gets transferred to the system as it gives way to seawater – one of the most absorbant substances known. The tundra is certainly melting, and very quickly too. Methane has been detectable in the Arctic waters since 2003 or earlier whereas it was not present before, suggesting that the methane hydrates and permafrost have been under stress and starting to leak for some time. Yet we have not reacted.
Second, it is hard to postulate another explanation. There are no other sources of methane on this scale to look to, other than huge deposits of submerged, rotting material not presently known to exist. So it would seem likely that whatever is causing this is triggering release from the methane hydrates and the permafrost.
OK, so it looks like positive feedback, but are there credible alternatives to climate change as the cause?
Not really. One could postulate that that is being caused by a different mechanism unrelated to climate change, for instance:
The permafrost cap in these areas may have been fractured by seismic activity. But if that was the case, these plumes would have been observed since time immemorial.
A large but localised geothermal hotspot could have caused the melting. But again, that possibility has always been around, so why has this not been seen until now? You could argue that as a result of the temperature changes in the Arctic waters caused by climate change, the permafrost cap has now been weakened by thawing to a state where it is vulnerable to such hotspots, whereas before it was not. This does still not seem as likely though, as so far we have no evidence linking what is happening to hotspots. But it is coherent enough to deserve further scrutiny to see if it stands up.
There are no other obvious ones at present. Of these, only one seems to stand up to even mild scrutiny. And it still looks close to a no-hoper alongside the positive feedback model.
So is it positive feedback for sure?
Not yet. It can be considered positive feedback when it is known to be either triggering a runaway release of the stored methane; or it causes runaway effects elsewhere in the climate system. Neither of these have yet been proven. But it is clearly a strong signal that the first may already be in train; and that may well give rise to the second over a longer period.
The first could be observed fairly readily, so should be obvious by the end of next summer at latest. The second depends upon how catastrophic the effect. The more so the quicker it will become apparent.
So what next?
The Arctic Ocean is now be freezing over again with the onset of winter, which will impede research in the short term. It also gives rise to a number of possible scenarios overwinter. If the methane release continues unabated or at an increasing rate it may either be trapped beneath the ice in huge bubbles or reservoirs, or it may dissolve in the sea water and diffuse somewhat.
If the former, there will be a colossal release of trapped methane about next March when the sea ice begins to break up, which should prove interesting. Once liberated to the atmosphere it will add to forcing, possibly by a significant factor depending on how much is released. This could lead to a significant hike in temperatures, and possibly to positive feedback in that respect.
If the latter, the release will be more attenuated. But this will make little difference to the net amount released or to the climatic effects medium to long-term.
Alternatively the rate of methane release may slow up over winter. This could result from a reduction of biological activity if this is a factor in play, or other unforeseen changes as a result of falling temperature.
Could it stop altogether for the winter... or forever?
The problem here is to find a mechanism that would cause that to happen.
If, as seems likely, the release is being caused by a weakening of the permafrost cap caused by melting, the only mechanism likely to stop that is if the cap refreezes again, sealing itself in the process. But that seems most improbable under present conditions, which are giving rise to long-term and potentially irreversible melting, generally through the region.
Sea ice may reform in winter, but it does so at the surface, and in fairly thin plates. The only conceivable way for this process to affect permafrost lying on or below the sea bed would be if the entire body of water from surface to sea bed were to freeze. Whilst the depths involved are not explicitly stated in the report, we must assume sufficient depth for the research ship to pass – say five metres at absolute minimum. Given that sea temperatures have been rising, and freezing delayed by the increased area of open water and by the milder climate generally, it seems vanishingly unlikely this would happen, short of a catastrophically severe winter, or more convincingly, a succession of them. That, in turn, seems highly unlikely for the same reasons.
Methane – that's pretty nasty stuff – right?
The worst greenhouse gas arising naturally and in quantity. Here's a cheat sheet from the Independent. The bad new is it is about 20 times more potent as CO2 as a greenhouse gas. The good is that it decays after around 12 years. But it fails to mention that it probably decays to CO2, so that is only the start of the story. Also both those figures are quoted quite variably in the various papers relating to this story. For instance the lifespan has been quoted at between 6 and 20 years, depending on conditions.
That's serious. So how much of this stuff is there?
A definitive study was published in September entitled Vulnerability of Permafrost Carbon to Climate Change: Implications for the Global Carbon Cycle which tells just about everything you could want to know on this subject. This estimates the total soil carbon in the northern circumpolar permafrost zone to be 1672 petagrams (Pg; 1 Pg = 1 billion metric tons), with 277 Pg of that in peat-lands. This doubled previous estimates, which means all previous climate modelling will be way out in this respect.
To put it in context 1672 petagrams is considered to be twice as much as currently exists in the atmosphere:
Overall, this permafrost C[arbon] pool estimate is more than twice the size of the entire atmospheric C[arbon] pool, and it is more than double previous estimates of high-latitude soil C[arbon](Gorham 1991, Jobbágy and Jackson 2000). The 0–3 m permafrost- zone soil C[arbon] estimated here at 1024 Pg represents a large fraction of world soil C[arbon] stocks; global soil C[arbon] stocks from 0 to 3 m depth (peatlands not included) have been estimated to be 2300 Pg (Jobbágy and Jackson 2000).
Twice as much as is up there now – that's curtains!
Global average greenhouse gases are currently at 385 ppm CO2 equivalent. Hypothetically if all that carbon is released it would treble that to 1155 ppm.
Well it all depends on what happens - but it sure doesn't look reassuring, to put it mildly. On thawing there will be a big spike as the gases that are currently trapped by the permafrost cap are released in large quantity. But most of this carbon is held in biological material requiring decomposition by microbes to release it, which is considered to be the dominant continuous process. Fire is the dominant episodic one.
In combination with dry conditions or increased water infiltration, thawing and fires could, given the right set of circumstances, act together to expose and transfer permafrost C[arbon] to the atmosphere very rapidly. Lastly, fire can interact with decomposition by creating warmer soil conditions and deeper permafrost thaw, which in turn promote the loss of C[arbon] from increased microbial activity.
Clearly the result will depend on the amounts of methane released, and the rate at which it is. But when they say very rapidly, they mean just that. We now have data from Antarctic ice cores proving that this happened at least twice previously, and at astronomical rates.
1155 ppm CO2? Can you put that in context?
The European Carbon Trading Scheme wa hailed as a big success as the first working carbon trading scheme, with the cap set at 550 ppm CO2. But as it soon became clear this would make absolutely no difference to climate change other than being a quick road to the hot house, it wasn't such a success after all.
IPCC4 caused massive angst when it brought the figure down to 450 ppm at the start of 2007, but by that summer the science had moved on so fast that it was clear that wouldn't save us either.
Various authorities then suggested we needed to limit CO2 equivalent in the atmosphere to 425 ppm or 400 ppm.
The soundest thinking emerged this June when James Hansen, a monumental figure in climate science, brought the figure down again to 350 ppm. This was discussed at length by the pensive prognosticator in“Finding oil isn't the issue – it is whether we want to find it, burn it and all fry” . But it must be confessed with one omission – it failed to stress that the actual levels already stood above the 380 ppm mark – 30 ppm or more into the danger zone. Which only goes to suggest that we have simply been waiting for something to blow, which might go along way to explain why this is happening. It all fits Hansen's model perfectly.
To give it a time line, 100 Months is based upon an estimate on when we will pass 425 ppm CO2. That campaign commenced on 01 August, so we are currently in month 98. However as 425 ppm looks incredible as a safe limit, it is unlikely we have that long. But don't let that put you off the campaign – that aside it is a good campaign, one of the few positive things going on and is well worth supporting.
If you take 400 ppm CO2 as the red line, we currently stand at 385 ppm. Greenhouse gases have been growing at 2 ppm per year and appear to be accelerating slightly. In addition we now have this new and significant source of methane to add to that. Make your own estimates on that basis – but if you get to a figure of more than seven and a half years from now, you've cooked it.
How soon will we know?
Winter conditions will impede research, and the presence of ice will obscure large-scale surface observations. Divers and mini subs might still be able to check out the sub-surface activity and the sources of methane. Surface measurements of trapped methane build up should still be possible.
Despite that it is unlikely we will have a good idea before:
the scale of the release of methane during the sea ice break up is know (next spring);
open water will allow direct observation of the extent of the plumes over a large area (next summer);
the renewed scale of activity and whether this is accelerating significantly is clear (probably not until late summer).
unless one or more proves to be catastrophic in scale, in which case we shall know all the sooner.
Further developments
Incredibly, only one.
Two days later, on 25 September, the Independent followed up with Hundreds of methane 'plumes' discovered . This story dealt with entirely unrelated research which had also just discovered the release of methane for the first time in a completely different part of the Arctic, this time off Svalbard in Norway. However the details are quite different.
At Svalbard there has been no prior investigation, the locations were much deeper, and the methane sources are not currently capped by permafrost. So it is conservatively assumed the process there has been going on for some 15,000 years. But this does not rule out that the scale is increasing in response to climate change, and clearly the researchers are onto that.
Unlike the first research it was able to confirm the source as methane hydrates degassing, in line with James Hansen's predictions.
Here is an extract or two.
'Yesterday, researchers on board the British research ship the James Clark Ross said they had counted about 250 methane plumes bubbling from the seabed in an area of about 30 square miles in water less than 400 metes (1,300 feet) deep off the west coast of Svalbard. They have also discovered a set of deeper plumes at depths of about 1,200 metres at a second site near by. Analysis of sediments and seawater has confirmed the rising gas is methane...'
'An analysis of sediments taken from the seabed show that the gas is coming from methane hydrates – ice-like crystals where molecules of the gas are captured in "cages" made of water molecules, which become unstable as water pressures fall or temperatures rise.
'Professor Westbrook said the area surveyed off the west coast of Svalbard was very different to the area being studied by the Russian vessel because the water was much deeper and does not have a layer of permafrost sealing the methane under the seabed.
'It is likely that methane emissions off Svalbard have been continuous for about 15,000 years – since the last ice age – but as yet no one knows whether recent climactic shifts in the Arctic have begun to accelerate them to a point where they could in themselves exacerbate climate change, he said.
'"We were very excited when we found these plumes because it was the first evidence there was an active gas system in this part of the world. Now we know it's there we know we have to very seriously consider its effect."'
And that - oddly enough - seems to be the entire media coverage to date on the most important news item in all of history.
It does not seem to have been picked up on by other periodicals. Nor has the Independent, which has to be praised for getting onto the story so fast, followed up. Searching has not brought up any scientific papers by the scientists quoted – which in itself is not unreasonable given that there are huge data sets to be crunched and analysed, conclusions to be tested and the paper itself to be produced.
But may leave you wondering why, if you missed the Independent stories first time around, you should have to be depending on a haplessly late story in the pensive prognosticator, a bottom of the heap blog, to bring you news which is arguably the most important in your life, critical to your entire future and a major factor in every decision you subsequently make. And the same for the world collectively.
But I leave that with you to ponder. And shall try to deal with the question as to how we should respond as individuals in the next instalment.
Stay happy
Sources
http://www.independent.co.uk/environment/climate-change/exclusive-the-methane-time-bomb-938932.html
http://www.independent.co.uk/news/science/hundreds-of-methane-plumes-discovered-941456.html
http://www.independent.co.uk/opinion/commentators/steve-connor-the-ultimate-gas-leak-that-scientists-dreaded-938935.html
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