Rebuttal to Michael Tobis' unsubstantiated attacks on the work of Shakhova

Why the jury's still out on the risk of Arctic methane catastrophe

Can scientists overcome huge uncertainties to pin down how close, or far, we might be to a tipping point?

Arctic iceberg. Photograph: Delphine Star/Getty Images

by Nafeez Ahmed, "Earth Insight," The Guardian, September 5, 2013

 About a week ago, climate scientist Michael Tobis wrote a critique of my 'Seven facts about the Arctic methane time bomb' following a twitter exchange with him and Chris Colose, author of an article at Skeptical Science arguing that the core scenario of a new Nature paper by Gail Whiteman et al. on the economic costs of Arctic climate change is extremely unlikely.

Much of this debate kicked off because the said Nature paper advances a hypothetical scenario for an abrupt Arctic methane release over either a decade or several decades of about 50 gigatonnes (Gt), and argues specifically that such a scenario is "likely." My own attempt to understand the literature convinced me that the scenario should be viewed as a serious possibility.

Tobis on the other hand is the latest amongst several scientists offering scathing criticisms of that scenario, which in his own words is "as close to impossible as anything in earth science; actual geophysics refutes it."

He begins with my first point, 1. The 50 Gigatonne decadal methane pulse scenario was posited by four Arctic specialists, and is considered plausible by Met Office scientists.

Tobis writes that the Review of Geophysics paper I cite says

"Arctic thawing may release in excess of 50 GT of C [Carbon], a very serious matter... But Ahmed refers to the paper in support of a very different assertion, that 50 GT of methane would be released... But the paper to which he points says nothing of the sort. I conclude that he doesn't really know what he is talking about. Specifically he has already shown that he is confused about the distinction between methane releases and CO2 releases."

However, the carbon release scenarios from permafrost explored by the paper include both methane and carbon. 

Here's what the paper says:

"The most important determinant of whether release of frozen carbon happens as CO2 or CH4 [methane] is whether decomposition proceeds aerobically or anaerobically... In anaerobic conditions, a greater proportion of soil organic carbon decomposition is released as CH4, although not all of it necessarily reaches the atmosphere."

Following this paragraph, the paper cites several scenarios for large-scale releases from permafrost carbon, including the 50-100 Gt carbon release I mentioned.

Further down, the paper continues:

"Thawing of the terrestrial permafrost will result in CO2 and CH4 emissions on time scales of a few decades to several centuries."

So Tobis is wrong in assuming that the carbon release scenarios the paper is discussing are only CO2 - that isn't specified, so I'd assumed the paper was open on whether the 50-100 Gt emissions were methane or carbon. 

This was a mistake, however. The paper makes clear that although the scenarios are not clear on the precise quantification of carbon dioxide compared to methane releases from permafrost thawing, methane releases would be only be a small percentage of the overall carbon release scenarios explored. So Tobis is ultimately correct - the paper does not back up the specific scenario endorsed as likely by the Nature paper. I stand corrected on that.

Therefore, the plausibility of the specific 50 Gt scenario rises and falls on the credibility of the four Arctic specialists, including Dr. Natalia Shakhova, who came up with the scenario in the first place. That leaves point 1 only half intact, so we're left with:

1. The 50 Gigatonne decadal methane pulse scenario was posited by four Arctic specialists
Tobis unfortunately addresses this with only an ad hominem attack on the expertise of these Arctic specialists:

"Whether we should be acknowledging the 'Arctic specialists' as actually expert is, frankly, the question at hand."

Tobis goes through my other citations of the literature arguing that I am confusing quantities and making unwarranted extrapolations. However, my citations of this literature is simply to clarify that the literature does not rule out potentially dangerous releases of Arctic methane. Does Tobis manage to refute point 2. Arctic methane hydrates are becoming increasingly unstable in the context of anthropogenic climate change and it's impact on diminishing sea ice? No. Arctic methane hydrates are becoming increasingly unstable. I said nothing more, or less, than exactly that.

What about fact 3. Multiple scientific reviews, including one by over 20 Arctic specialists, confirm decadal catastrophic Arctic methane release is plausible?

Tobis concedes "A couple of reviews do give some support to this, but are vague about time scales." He then links to what he describes as a "DOE report." Instead, the link goes through to a Geophysical Research Letters study, which, however, he completely ignores, instead quoting from the original Review of Geophysics paper as follows: 

"The risk of a rapid increase in [methane] emissions is real but remains largely unquantified..." 

And he calls me confused! 

He then argues that there is "plenty of room for acceleration without hitting the cataclysmic level. Further evidence doesn't support the immediacy of that scenario at all."

But the Review of Geophysics paper does NOT say that there is "plenty of room for acceleration without hitting the cataclysmic level" - it says that:

"... significant increases in methane emissions are likely, and catastrophic emissions cannot be ruled out."

The paper does NOT say available evidence "doesn't support the immediacy" of a catastrophic scenario, but rather that "uncertainties are large, and it is difficult to be conclusive about the time scales and magnitudes of methane feedbacks."

As for the Geophysical Research Letters study Tobis links to but ignores, it says:

"... while many deep hydrate deposits are indeed stable under the influence of rapid seafloor temperature variations, shallow deposits, such as those found in arctic regions or in the Gulf of Mexico, can undergo rapid dissociation and produce significant carbon fluxes over a period of decades."

I think my fundamental contention - that the scientific literature recognises the possibility of some sort of catastrophic methane scenario - remains valid. Tobis is right, however, to emphasise that there is very little evidence available on quantifying that possibility.

In response to fact 4. Current methane levels are unprecedented, Tobis says yes, but they are "not climbing rapidly", and therefore this is mere "hype." My intention here was not to suggest that current Arctic methane levels are definitive evidence of a catastrophe already underway, but simply to note that it is wrong to say methane levels are NOT rising. They are, and once again, Arctic specialists are concerned. 

According to Charles Miller of NASA's new research programme, Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE):

"The CARVE science team is busy analyzing data from its first full year of science flights. What they're finding, Miller said, is both amazing and potentially troubling.

'Some of the methane and carbon dioxide concentrations we've measured have been large, and we're seeing very different patterns from what models suggest," Miller said. "We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze. To cite another example, in July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels. That's similar to what you might find in a large city.'

"Ultimately, the scientists hope their observations will indicate whether an irreversible permafrost tipping point may be near at hand. While scientists don't yet believe the Arctic has reached that tipping point, no one knows for sure. 'We hope CARVE may be able to find that "smoking gun," if one exists,' Miller said."

So while NASA Arctic specialists say Arctic methane levels are "amazing" and "potentially troubling," outside the range of most model predictions, and possibly indicative that "an irreversible permafrost tipping point" is near - a matter which "no one knows for sure" - Tobis wants to interpret all the evidence as "refuting" any need for concern. 

The other problem is that Arctic monitoring is still poor, and might be missing significant methane emissions. As Shakhova and her co-author Igor Semiletov told the New York Times' Andy Revkin:

"It is no surprise to us that others monitoring global methane have not found a signal from the Siberian Arctic or increase in global emissions... The number of stations monitoring atmospheric methane concentrations worldwide is very few. In the Arctic there are only three such stations - Barrow, Alert, Zeppelin - and all are far away from the Siberian Arctic. We are doing our multi-year observations, including year-round monitoring, in proximity to the source. In addition to measuring the amount of methane emitted from the area, we are trying to find out whether there is anything specific about those emissions that could distinguish them from other sources. It is incorrect to say that anyone is able to trace that signal yet."

Most Arctic specialists recognise that there's simply not enough research to justify dismissing the possibility of a catastrophe. That sword cuts both ways, of course - equally, there's not enough research justifying conclusions that we are definitely on the brink of a catastrophe.

On 5. The tipping point for continuous Siberian permafrost thaw could be as low as 1.5 C, Tobis concedes this "is on the table," but that "it has nothing to do with undersea methane." Um, I never said it had anything to do with undersea methane.

On 6. Arctic conditions during the Eemian interglacial lasting from 130,000 to 115,000 years ago are a terrible analogy for today's Arctic, he writes: "as a response to Chris Colose" this is a "terrible" response, "because Colose is not relying on the Eemian but on the early Holocene as the analogous period." Yes, Colose does refer to the early Holocene, but he also repeatedly refers to the Eemian, the "Last Interglacial period between 130,000 to 120,000 years ago." In a previous article, I'd already mentioned that in the early Holocene, the East Siberia Arctic Shelf (ESAS) was "not an underwater shelf but a frozen landmass" as reason to be sceptical that paleoclimate data provide a ready analogue for the present.

Tobis then launches an ad hominem attack on climate scientist Paul Beckwith, whom I quoted for this article, and whom Tobis refers to as:

"'Prof' Paul Beckwith, the 'Professor Beckwith' who is a grad student at Ottawa U."

For the record, earlier this year, Beckwith formally passed his PhD examination on abrupt Arctic climate change at the Laboratory for Paleoclimatology and Climatology, University of Ottawa, where he is currently a part-time professor in climatology. Rather than addressing Prof Beckwith's argument, Tobis wants to demean his reputation and ignore his argument (which he fails to refute). Beckwith's full response to Colose is here. Among Beckwith's points, he argues that neither the early Holocene nor Eemian offer good analogues for the present Arctic:

"Earth tilt was larger, so Winter Northern Hemispheric solar radiation was about 40 W/m2 lower than today at 60 degrees North. Thus, the ice formed much more quickly and much thicker in the winter back then. Also, at night much more heat was radiated out to space in the lower GHG world then as compared to our 400 ppm levels today... the summertime Arctic is not believed to be seasonally ice free during these periods. The last time this happened was likely 2 or 3 million years ago... Colder winters in the early Holocene and Last Interglacial and much colder nights (in summers and winters then) meant much thicker and extensive ice formation in winters, and slower melting at night, respectively."

If I was to take Tobis' approach, I could have noted that Chris Colose is a "grad student" at the University of Albany. I didn't, because it's irrelevant.

Finally, Tobis takes on fact 7. Paleoclimate records will not necessarily capture a large, abrupt methane pulse with the following obfuscation: "Now, we swing back to saying that it HAS occurred in the recent geological past, indeed at the time which Colose says is the better analogy." 

This is incorrect. Here, I merely point to a paper in Science by Nisbet which argues specifically that the cold Younger Dryas was ended due to methane emissions which came mostly from wetlands, but for which the initial trigger could have been Arctic methane clathrates:

"A possible explanation for the sudden end of the Younger Dryas is that, at a time of high Arctic insolation, an initial outburst of methane - perhaps from a geological source such as methane clathrates - triggered global warming, initiating both strong wetland emission in the tropics and north (8), and further hydrate responses as the thermal shock penetrated the permafrost (9, 10), freeing methane from decomposing clathrate hydrates and releasing gas pools trapped beneath them."

The evidence for this, however, is inconclusive, so the paper concludes: "The jury thus remains out on the initial trigger..."

On the issue of whether paleoclimate records will actually capture a large, abrupt methane pulse such as the scenario proposed by Shakhova et al., as this paper in Earth and Planetary Science Letters observes, "rapid methane perturbations in the atmosphere are strongly smoothed in ice core records" due to "the relatively short atmospheric lifetime of methane." So it is quite possible that an abrupt, catastrophic methane release of the sort Shakhova proposes has happened, but is undetected in ice cores.

Tobis then declares a "scientific consensus has been reached" that Shakhova's scenario is "implausible in the extreme."

But the scientific consensus amongst ESAS experts is quite different, as I'd already noted. A peer-reviewed study by 20 Arctic specialists of ESAS data from 1995-2011, drawing of course also on Shakhova's work, specifically recognises:

"The emission of methane in several areas of the [ESAS] is massive to the extent that growth in the methane concentrations in the atmosphere to values capable of causing a considerable and even catastrophic warning on the Earth is possible."

It seems clear to me that the scientific literature on the danger of an Arctic methane catastrophe recognises the possibility unequivocally, but highlights huge uncertainty in our knowledge of the processes at work. Most of the literature I've been able to find on this subject shows great humility - and while acknowledging the possibility of worst-case scenarios, makes quite clear that the likelihood of those scenarios is very difficult to gauge.

The Nature paper by Whiteman et al. went too far in stating the Shakhova et al. scenario as "likely." But on the other end of the spectrum, in the comments to his own blog, Tobis hints that Shakhova et al. are involved in "junk science" - despite the fact that their papers have been published in peer-reviewed journals (their 50 Gt scenario is discussed in this paper originally published in the Proceedings of the Russian Academy of Sciences), and that their general thesis is taken seriously by the US National Science Foundation.

Tobis also refers to a response to the Whiteman paper submitted to Nature (though not yet published) by Nisbet et al., which argues that Shakhova's scenario is "improbably large" as there is no evidence for such events during past "glacial/postglacial transitions."

This is certainly a notable contribution to the debate, but if past paleoclimate conditions are not a good analogue for present Arctic conditions - a matter which remains a matter of scientific debate - and if ice cores would not record such a rapid scenario, then the central argument of this paper may be questionable.

Indeed, a 2007 Royal Society paper by NASA scientist Drew Shindell backs this up:

"... the rarity of palaeoclimate evidence for hydrate-induced climate changes argues that this is a fairly unlikely candidate for near-term sudden climate change. Unlike the others, however, anthropogenic climate change may alter the probability of hydrate release when compared with the past, making the overall probability of near-term release extremely difficult to estimate...
Massive methane release by hydrates or from peats also seems to have been extremely rare in the past, but could become more probable in the future world under the influence of anthropogenic forcing. However, at present, it is not possible to judge the probability for such changes reliably."

Shindell's argument offers a warning that lack of past evidence is not a reason for present complacency where anthropogenic forces are changing the climate in ways not necessarily captured by paleoclimate evidence. 

So where does this leave us with regard to the risk of abrupt, catastrophic methane releases? As far as I can discern, the literature is largely agnostic about it, emphasises that specific scenarios are difficult to quantify, and calls for further research. The Review of Geophysics paper, for instance, far from asserting that a catastrophic methane release is refuted by geophysical evidence - as Tobis says - concludes:

"A significant increase in CH4 emissions and atmospheric concentrations due to climate change is therefore a possible scenario for the next century. However, uncertainties are very large, and as discussed above, it is difficult to be very conclusive regarding the magnitude of CH4 feedbacks and their time scales."

What about Shakhova et al.'s specific scenario of a potential 50 Gt methane release at any time (the basic contours of her argument are outlined here, no paywall)? Shakhova et al. say simply that the scenario should be taken seriously as a possibility underscoring the importance of further ESAS research. The fact that Nature co-author Prof Peter Wadhams, who heads up polar ocean physics at Cambridge, also takes it seriously, is significant. Is Prof Wadhams' expertise also to be attacked? Ultimately, in my view, Tobis fails to show either that this scenario specifically, or abrupt methane catastrophe more generally, are unlikely. 

In particular, his claim that there is a scientific consensus demonstrating near impossibility of a risk of a catastrophic methane event strikes me as unsupportable. Disagreement among scientists over the Arctic methane question is real, and it seems clear that Arctic specialists - Shakhova included - largely agree that while catastrophe is possible, more research is needed to discern how likely or unlikely it might be.

While other scientists, many reputable, argue importantly that such scenarios are beyond the pale, to my mind Tobis' egregious ad hominems against Arctic scientists whom he disagrees with have no place in scientific debate.

Dr Nafeez Ahmed is executive director of the Institute for Policy Research & Development and author of A User's Guide to the Crisis of Civilisation: And How to Save It among other books. Follow him on Twitter @nafeezahmed

http://www.theguardian.com/environment/earth-insight/2013/sep/05/jury-out-arctic-methane-catastrophe-risk-real

In response to a comment, Dr. Ahmad wrote:

The simple purpose of my articles on the Arctic methane question have been to investigate whether the scientific literature bears out the possibility of a catastrophe. Apart from the fact this issue is obviously of interest to anyone, my own particular interest in the issue is related to how such an event would impact our societies, economies and geopolitics. 

Of course, I'm not an expert on this issue. Anyone can see that from my bio. Should that prevent me from trying to understand and engage with it?

It's mistaken to think that I am disrespecting the scientist bloggers who think Shakhova's scenario specifically and an abrupt methane catastrophe scenario generally have negligible probability. While these scientist bloggers have articulated their views very well, the reality is that there are lots of other scientists - their views being expressed in the literature - who argue that we cannot rule out such scenarios, and that we cannot even know for sure how likely or unlikely they are.

Now Semiletov and Shakova are clearly at the forefront of research on the East Siberian Arctic Shelf (ESAS), and are the main people arguing that the ESAS harbours a unique danger of abrupt climate change due to conditions not found anywhere else on the planet. 20 Arctic specialists agree with them.

Perhaps they are wrong, and the scientist bloggers critiquing them are right. But I don't know that, and looking at the peer-reviewed literature, I cannot see any arguments which support the idea that Shakhova is talking complete nonsense. Yes, there have been several of blog posts by scientists and science students suggesting this - but all the peer-reviewed analyses of the question of Arctic methane risks by leading scientists in the field show that there is a possible danger here which cannot be quantified.

Now Tobis is openly arguing, effectively, that Shakhova and her colleagues are non-experts, and that they offer no evidence for their claims. So who is disrespecting scientists, really? As a mere journo trying to get to the bottom of this, as a mere HUMAN trying to get to the bottom of this, I'm genuinely trying to understand how Tobis and others can insist Shakhova et al. offer ZERO evidence at all. How can they be permitted to deliver papers at scientific conferences, how can they be publishing in peer-reviewed journals (and I note that their 50 Gt abrupt methane release scenario was also peer-reviewed too) if all they are doing is junk science? Shakhova is repeatedly arguing that significant portions of the ESAS is underlain by methane gas hydrates which are relatively shallow and vulnerable to destabilisation, based on direct observation and sampling. Is she lying? Is she deluded? And are the Arctic specialists reviewing her and others' ESAS research who think there is something to their findings also deluded and/or liars?

I just find this really difficult to believe. It doesn't seem credible to me that Shakhova et al. and the Arctic scientists who support them/consider them credible - many of them leading experts in the field too - are just talking nonsense and junk science combined with unwarranted speculation. If that's the case, how the hell are they getting published in leading science journals? And why do so many Arctic specialists agree with them? Prof Peter Wadhams from Cambridge told me that there is a relative consensus on the possibility of danger amongst ESAS experts. Is he just lying too? Or deluded?

If that IS happening, then there is a fundamental problem with the scientific process here, Shakhova et al. need to be put in their place, and we should all be worried about how a large number of Arctic specialists can be taken in by complete speculative nonsense.

From my perspective, I see two sets of experts - most Arctic specialists themselves, who will not rule out the possibility that Shakhova might be right and who respect her work - and a lot of non-Arctic experts who, however, may well have expertise in methane hydrates generally or climate modelling, who find Shakhova's arguments far-fetched and evidence-thin. 

It's in this context of disagreement that I've tried to see what the peer-reviewed literature itself says, and I've tried to let the lit speak for itself as much as is possible here. I don't see any lit which proves any scientific consensus demolishing Shakhova et al. 

Readers are encouraged to do their own research and make up their own minds, and yes of course, to read up on my links (please don't tell me you like reading blogs hoping for gospel truth - the links are there to be read and checked as supporting evidence!) and if you disagree with my conclusions, the key thing that would help me is to see how and why Shakhova et. al are not actually providing compelling evidence for their arguments. 

I won't be able to respond further for a while as I'm away, but will read constructive comments with interest.

 

Read More

MUST READ: What climate scientists talk about now (Financial Times Magazine)

What climate scientists talk about now

by Pilita Clark, Financial Times Magazine, August 2, 2013

As the Intergovernmental Panel on Climate Change prepares to release its latest report, Pilita Clark meets some of the key scientists behind it.

 

 

©Thom Atkinson. David Vaughan, glaciologist with the British Antarctic Survey

 

David Vaughan was sitting in his office in Cambridge when he first saw the grainy black-and-white picture of something he had never thought possible. It was a satellite image of a huge ice shelf on the edge of the South Pole in an area he had been studying with his colleagues at the British Antarctic Survey research centre. At least, it was supposed to be.

This was 1995 and Vaughan, a glaciologist with the careful manner of the solicitor he once thought of becoming, looked at the spot where the shelf had been and thought, “The damned thing’s not where it’s supposed to be.”

“It was like looking at a map of Britain and seeing half of Cornwall had disappeared,” he told me recently.

This was baffling, and disconcerting, because ice shelves act like giant doorstops that block the world’s last two ice sheets, in Antarctica and Greenland, from oozing faster towards the ocean. Those sheets are a frozen menace to civilisation – they would push up global sea levels by more than 60m if they ever slid into the sea. So a plane was dispatched to check on what Vaughan’s picture really showed. Its crew returned with startling news: the ice shelf had gone.

Arctic sea ice volume

The so-called 'Arctic death spiral', charting the decline in summer ice

“They came back with these fantastic photographs of a whole area of football pitch-sized icebergs that were just floating off,” said Vaughan. “That was the first time we’d ever seen anything like that virtually collapse overnight.”

It was not the last. Today, seven of the 12 ice shelves that once fringed that part of the Antarctic have either collapsed or shrunk, along with 81% of its 300 glaciers. And while temperatures have not risen across the entire Antarctic continent, the area that Vaughan was studying has warmed by about 3 C in the past 50 years, much faster than global temperatures have risen.

Vaughan never thought about the natural world in the same way again. Today, he is a prominent author of a mammoth international report that will start to be published next month on one of the most fraught public policy issues of our age: climate change. This will be the first assessment report in six years from the Intergovernmental Panel on Climate Change, the UN body created in 1988 to give governments an expert technical appraisal of how the climate is changing and why. There have only been four such reports before – in 1990, 1995, 2001 and 2007. Many of the scientists writing them have had experiences like David Vaughan’s that have convinced them the climate is changing profoundly, a conclusion each of their reports has confirmed with growing confidence.

 

©BAS. A 1995 satellite photograph which revealed the disappearance of a huge ice shelf on the edge of the South Pole

 

But this report will be unlike any other. For one thing, it is the first since the IPCC was plunged into two controversies four years ago, one over claims that hacked scientists’ emails showed some IPCC authors had tried to hide data undermining their findings on global warming [shown to be a trumped up scandal with no merit]; another about an error in the 2007 report suggesting Himalayan glaciers could melt by 2035 [a minor error in a report that looked at thousands of papers]. It is also the first since it became so clear that, despite a relentless rise in carbon dioxide emissions, global temperatures have not risen nearly as fast over the past 15 years as they did in previous decades [while the deep oceans are warming faster than ever]. And it will be the last before world leaders meet in Paris in 2015 to finalise a legally binding agreement to tackle climate change, which will be guided by the IPCC’s latest findings.

This means the report will be one of the most carefully analysed documents on climate change this decade, probed and picked apart by the thousands of people around the world for whom the subject has become a driving passion. Yet interviews with some of the scientists who have drafted the new assessment reveal the IPCC is still a curiously misunderstood body, made up of people with widely differing views about how the climate is changing and even about the value of the IPCC itself.
. . .
There is nothing else quite like the IPCC. No other branch of science appraises everything of note published in its field for several years on end and puts it together into one enormous study. Each assessment report is so big it is published in stages over the course of a year. The last one weighed in at 20 lbs. on my bathroom scales and ran to more than 3,000 pages. The one that will start to be published next month is set to be even bigger, in line with an explosive growth of climate science research. The first IPCC assessment in 1990 had 97 main authors. This one has 840.

In the wake of the “Climategate” and “Glaciergate” controversies four years ago, a raft of inquiries eventually found no evidence of serious wrongdoing, let alone anything to raise doubts about the IPCC’s conclusions. But the scientists remain the target of a vigorous group of critics sceptical about their work. They have been branded “criminals” (Britain’s Lord Monckton) guilty of “massive international scientific fraud” (US senator James [No]Sensenbrenner) who should commit “hara-kiri” (US pundit Glenn Beck) for duping the world with “snake oil” (former Alaskan governor Sarah Palin).

This has had an impact on the people doing this latest IPCC assessment, according to several of the scientists interviewed for this article. “I see it in the tension in the author team,” as they check, recheck, then check again all their work, said David Vaughan. “I think there is a point at which that kind of stress can become difficult to manage,” he added, explaining it has made IPCC work “a very cumbersome, slow process.”

These furores have also added confusion to what is still a widely misunderstood scientific endeavour. For one thing, the IPCC does not actually exist, at least not in the way many imagine it does, with a staff of comfortably remunerated researchers beavering away to produce its reports. Instead, it relies on hundreds of mostly government-nominated scientists working for free for large parts of the several years it takes to produce the assessments for the IPCC’s 195 member countries, all of which are ultimately supposed to approve the report summaries.

The report authors are divided into three working groups: one on the physical science; one on how to adapt to climate change; and one on how to curb it. The most closely watched is Working Group I, on the physical science of climate change, whose report is coming out next month. 

The largest share of authors comes from the US and then the UK, which has long been disproportionately represented in the IPCC. For more than half the panel’s life there has been a British scientist either chairing it or leading Working Group I, thanks to a drive to fund climate research dating back to former prime minister Margaret Thatcher.

Perhaps the least understood aspect of the IPCC, however, is how it is run. Its work is supported by a secretariat based in the home of international secretariats, Geneva. But unlike the nearby World Trade Organization, which has 629 regular staff, or the World Health Organization up the road, which has more than 1,800 in its headquarters, the IPCC has just 12 full-time staff in a strip of offices on the eighth floor of the World Meteorological Organization.

The day I visited in late June, I met Renate Christ, the Austrian scientist who has headed the IPCC secretariat since 2004, and asked what her annual budget was this year. “It goes between $7m and $10m,” she said, peering at her computer to check exactly what it was for 2013. It turns out that the amount of money the world has come up with to fund the headquarters of the body producing the last word on what Barack Obama recently called “the global threat of our time” is $9.3m this year, about the same as Cumbria spent fixing potholes last year.

If you sat down and read all the IPCC’s reports together, which few ordinary mortals ever do, you would read a story of growing scientific conviction that the Earth is warming and that it is probably because of the greenhouse gases humans have produced since they took to burning fossil fuels such as coal and gas in ever more prodigious quantities from the industrial ­revolution onwards.

The last assessment, in 2007, said average global surface temperatures had gone up 0.76 C since 1850, had accelerated in recent decades, and were rising nearly twice as fast in the Arctic. The oceans were warming; glaciers were suffering “widespread mass loss”; and sea levels were rising. Global warming was therefore “unequivocal”, the report said, and most of the temperature rises seen since the mid-20th century were “very likely” due to the increase in human-made greenhouse gases, the most important of which is carbon dioxide.

 

©Klaus Thymann for Project-Pressure.org; The Fenris glacier in the Sermilik fjord on the southeast coast of Greenland, photographed in 1932-1933 (left) and in 2012. The glacier has retreated by 5,000 m, with the rate of retreat increasing rapidly in the past decade. Photos copyrighted by Klaus Thymann for Project-Pressure.org; The Natural History Museum of Denmark

 

A leaked draft of the new fifth assessment done in October last year said this conclusion had only been strengthened by newer data and that heatwaves were also more likely in many parts of the world, as well as heavy rains.

But there is one thing the final version must include when it is published next month, according to Sir Bob Watson, the British scientist and climate action advocate who chaired the IPCC for nearly six years up to 2002. “I think the current Working Group I report must address in detail the slowing down in the last 10 years,” he said, adding that although the past three decades were probably the warmest in 1,000 years, “there is also no question that it would appear that the rate of change in the last decade or so is definitely slower than the previous two decades.”

“The IPCC must address this because the climate deniers are linking on to this as a reason to say we’ve got all the science wrong. So I think one of the very most important issues is indeed for them to address this issue absolutely head on.”

The extent of this slowdown depends on how one measures it. Each of the past three decades has been warmer than the previous one and the long-term trend since the 1850s clearly shows a steady temperature rise. However, the average rate of warming was 0.17 C per decade between 1970 and 1998 and just 0.04 C per decade from 1998 to 2012, according to one of the main global temperature data sets. [these are the land temperatures -- most of the planet is covered by oceans and they continue to warm at even faster rates]

Slowing temperature rises have happened before, notably between the 1940s and 1970s. But the recent slowdown has come even though the amount of carbon dioxide in the atmosphere reached 400 parts per million earlier this year, the highest level in millions of years. 

This issue is so new that it was barely considered when the IPCC first met in 2009 to decide what would be in its next assessment and there is still no agreed name for it. Many scientists have started to call it the “hiatus” or “pause” and though it will be addressed in the final report, there is still no consensus on what has caused it. Some think it is happening because the oceans are absorbing more heat than once thought, especially at very great depths. Others think aerosols, tiny airborne particles from volcanic eruptions or industrial pollution that reflect sunlight away from the Earth could be having more of a cooling impact.

The most contentious theory – and the one global warming sceptics are most interested in – is that the climate is not as sensitive to carbon dioxide emissions as previously thought. Even if this proves correct, all the climate models used by the IPCC for its latest assessment show that if greenhouse gas emissions continue at current rates, the world will still exceed this century the 2 C warming from pre-industrial levels that some scientists believe could prompt dangerous forms of climate change.

But in a sign of what a potent issue the slowdown is becoming, politicians in the US and the UK are already asking if it means they can ease back on contentious measures to curb global warming such as offshore wind farms or carbon pricing.
. . .

 

©Yann Mingard.Thomas Stocker co-chair, IPCC Working Group I report

 

The man at the centre of the IPCC’s new assessment is a gruff Swiss environmental physicist named Thomas Stocker, co-chair of the Working Group I report. After a lifetime spent in the trenches of climate science he is a man of firm opinions. He likes the cerebral American jazz pianist, Keith Jarrett, and spotting orchids. He ­dislikes a lot of things, including people addicted to smartphones (his own ancient device does almost nothing but take calls), the falling rate of scientific literacy in western society, and poorly run meetings, which he says are “just terrible” and even “irresponsible.” When I saw him in the airy office he has occupied at the University of Bern for the past 20 years, the walls were plastered with reproductions of some of his team’s best-known scientific publications, including a chart showing that concentrations of carbon dioxide in the past 200 years rose to levels more than 30% higher than at any time in the past 800,000 years.

“That’s the most impressive hockey stick,” he said proudly, a reference to the famously contentious graph first published in the late 1990s by the US scientist, Michael Mann, and colleagues. This showed temperatures stayed roughly flat for nearly 1,000 years, like the handle on a horizontal hockey stick, before rising sharply in the 20th century, like the blade, after fossil-fuel emissions began to soar. Climate sceptics have spent years attacking it and Mann because it was such a simple picture of the link between global warming and rising carbon dioxide emissions.

Stocker says, however, that it was his team’s research that was used in the Al Gore film, An Inconvenient Truth, for the part where Gore uses a forklift to illustrate the relative level of today’s ­emissions compared with those of the past.

He is characteristically brusque about the idea that the recent slowdown in warming suggests politicians can ease up on measures to curb global warming because scientists were mistaken about climate sensitivity. Such questioning is based on “complete disinformation,” he said, pointing out that even the IPCC’s best estimates are always given together with a range of upper and lower projected temperatures. In any case, he said, 15 years of slower warming is simply too short a timeframe on which to base a judgment. “If we found that indeed for 30 years the temperature didn’t go up and CO2 went up with the rate that we observe today, then of course that would pose serious ­questions. It’s absolutely clear,” he said.

But is it possible that temperatures are not responding to carbon emissions as vigorously as scientists once thought or do we know if the oceans are absorbing more heat? “If we knew one, we could actually make a statement about the other,” Stocker said. “It’s really coupled. We’re not in a position to say either/or.”

It is a similar picture for aerosols. “I think generally there is a large uncertainty,” he said, adding that the current rate at which fossil fuels are being burnt means a considerable amount of warming is nonetheless certain.

Stocker remains resolutely confident about the robustness of the IPCC’s projections overall. “There is no other science and there’s no other activity of humans that looks into the future that has done so well as the IPCC,” he said. “Ask how well do the GDP projections fare for the next month. Ask how well do the projections of crop yields for the next year. Ask how well projections of DAX [the blue-chip German stock index] and all these other indices fare.”

 

©Thom Atkinson.Peter Wadhams, review editor, IPCC Working Group I report

 

One doesn’t need to look far to find IPCC scientists who are – for different reasons – even less flattering about some of its work, including one helping to shape the latest assessment. Peter Wadhams, a leading expert on Arctic sea ice at Cambridge university, is a review editor on the new Working Group I report. He was pleased to be involved with this one because he was so upset about certain aspects of the last IPCC assessment in 2007.

“They made a couple of real clangers there,” he said gloomily, staring around his cluttered lair in the university’s Department of Applied Mathematics and Theoretical Physics. One was a contentious decision not to include a best estimate for future sea level rises because it was thought the potential impact of ice sheets was still too poorly understood. Wadhams, along with other critics, believes this led to a serious underestimate of how high sea levels will rise. “They just chickened out,” he fumes. “I mean, in a really systematically cowardly way. And it shows how naive these scientists are or how terrified of sticking their neck out.”

Thomas Stocker, who had a hand in drafting that earlier report, said uncertainties about how the ice sheets were changing made it impossible to include them in the way Wadhams thought they should have been. “Our purpose in AR4 [the earlier assessment] was not to report the highest numbers which would make headlines, but it was to report the numbers that we can defend,” he said.

But Wadhams is even angrier about another line in that last IPCC report suggesting it could take until the latter part of this century before Arctic summer sea ice disappears almost entirely. The sea ice that covers much of the North Pole always melts a little in summer and then refreezes as winter sets in. Last summer, however, it shrank to its lowest point in more than 30 years, a much more dramatic decline than predicted. Wadhams thinks it more likely that its summer sea ice will vanish as soon as 2015.

“It could even be this year or next year but not later than 2015 there won’t be any ice in the Arctic in the summer,” he said, pulling out a battered laptop to show a diagram explaining his calculations, which he calls “the Arctic death spiral.”

This prediction is frequently described as too extreme by other climate scientists writing for the IPCC. But Wadhams says this only underlines the “very conservative” views of the body, which has far too many government scientists who are “in the business of really generating complacency.” He even has doubts about how much value there is in today’s IPCC assessment reports, which he thinks have become too big to be widely useful. “I mean, those thick ones are kind of monuments to man’s arrogance or man’s beavering away. It’s to say, ‘Hey, look, aren’t we wonderful, there’s more of us doing climate research than ever before in the world, we’re all doing more and this is what we’ve done and aren’t we great.’ 

“But the trouble is a reader who’s not a scientist is going to say, ‘Well, so what? There’s 50lbs of book, what does it tell me?' ”
. . .
Perhaps the greatest danger to the IPCC, however, is how cumbersome it has become to produce its assessments. The length of time between reports has always made some of its findings slightly outdated, but the process is also increasingly taxing for the volunteer scientists involved. Professor Jonathan Gregory, a leading expert on sea levels and an IPCC report veteran, had been working nonstop the day I saw him at Reading University. “It’s pretty near, I think, the limit of what one can do without it being a job,” he said. “It’s taken a colossal amount of my time this time.”

“I’ve been working on the IPCC Report in the last two months about 35 hours a week,” Gregory added, “but then I have to work another 25 hours to get all the other stuff done, or at least keeping it ticking over. So it is pretty difficult, really.”

 

©Yann Mingard.Thomas Stocker, co-chair IPCC Working Group 1, in Jungfraujoch, Switzerland

 

Across the corridor, another IPCC author, Professor Rowan Sutton, was even blunter. “This has been a phenomenally protracted process,” he said. “I’m not sure I would do it again. I mean I don’t think I’ve got the time to do it again really. I do also think that the process needs to change to make it more manageable.”

This change could happen. Earlier this year, Renate Christ from the IPCC secretariat sent a letter to all the governments that commission the panel’s reports asking them to consider “the future of the IPCC” in time for a meeting to be held in October in the Georgian city of Batumi. Similar reviews have been done in the past but one question up for debate this time, according to an accompanying background document that was sent out, is “should the IPCC continue to give priority to comprehensive assessment reports”, with smaller special reports. Another was whether it should do more “focused thematic reports that would jointly constitute an assessment report.”

This would be quite a change for a body that has played such a profound role in shaping the way we think about climate change. And it would make the latest IPCC assessment report even more distinct from its predecessors because, depending on what governments end up deciding, there is a chance that this one could be the last of its kind. 

http://www.ft.com/intl/cms/s/2/4084c8ee-fa36-11e2-98e0-00144feabdc0.html

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Huge methane belch in Arctic could cost $60 trillion

by Fred Pearce, NewScientist, July 25, 2013

A sudden methane burp in the Arctic could set the world back a colossal $60 trillion.

Billions of tonnes of the greenhouse gas methane are trapped just below the surface of the East Siberian Arctic shelf. Melting means the area is poised to deliver a giant gaseous belch at any moment -- one that could bring global warming forward 35 years and cost the equivalent of almost a year's global GDP.

These are the conclusions of the first systematic analysis of the economic cost of Arctic melting, which delivers a sobering antidote to other, more upbeat assessments that say melting in this area would improve access to minerals on the ocean bed, increase fishing and create ice-free shipping lanes.

Previous work has estimated that more than a trillion tonnes of methane lie under the shelf, trapped inside lattices of ice known as hydrates, at depths as shallow as 20 metres. Concern about a possible eruption has grown since 2010, when research cruises over the shelf by Natalia Shakhova and Igor Semiletov, both now at the University of Alaska at Fairbanks, found plumes of methane as much as a kilometre wide bubbling to the surface.

The pair calculated that a release of 50 billion tonnes would be possible within a decade, through known areas of melting and geological faults. Since methane is a greenhouse gas 25 times as potent as carbon dioxide, such a scenario would trigger a "climate catastrophe", they say, increasing the methane content of the planet's atmosphere twelve-fold, and raising temperatures by 1.3 ˚C.

Now, environmental economist Chris Hope and Arctic Ocean specialist Peter Wadhams, both at the University of Cambridge, together with climate policy analyst Gail Whiteman of Erasmus University in Rotterdam, the Netherlands, have analysed the likely consequences of such a release occurring between 2015 and 2025. They did so by adding the extra emissions to an existing model used in the UK government's 2006 Stern Review, designed to assess the economic cost of coping with climate change between now and 2200.

Economic time bomb

"The global impact of a warming Arctic is an economic time bomb," says Whiteman. A release of 50 billion tonnes of methane would bring forward by 15 to 35 years the date at which global temperature rise exceeds 2 ˚C above pre-industrial levels, the model shows, with most of the damage in the poorer parts of Africa, Asia and South America. The largest costs envisaged include loss of crops to heat and drought, coping with sea level rise and worsening tropical storms.

So how likely is a giant belch? An abrupt release of 50 billion tonnes is "highly possible at any time," Shakhova says.

Around 10 million tonnes of methane a year are already leaking from the shelf, according to Shakhova's calculations. However, it is not clear whether this is a new phenomenon, or even whether human activity is to blame. Shakhova says it may have been going on since the frozen shelf was inundated by seawater at the end of the last ice age.

Journal reference: Nature, Vol. 499, p. 401.

This article appeared in print under the headline "Vast methane belch possible at any time"

http://www.newscientist.com/article/dn23923-huge-methane-belch-in-arctic-could-cost-60-trillion.html

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White House warned on imminent Arctic ice death spiral

National security officials worried by rapid loss of Arctic summer sea ice overlook threat of permanent global food shortages

The melting of sea ice in the Arctic has caught the eye of the US Department of Homeland Security and the Pentagon. Photograph: John McConnico/AP

Senior US government officials are to be briefed at the White House this week on the danger of an ice-free Arctic in the summer within two years.

The meeting is bringing together NASA's acting chief scientist, Gale Allen, the director of the US National Science Foundation, Cora Marett, as well as representatives from the US Department of Homeland Security and the Pentagon.

This is the latest indication that US officials are increasingly concerned about the international and domestic security implications of climate change.

Senior scientists advising the US government at the meeting include 10 Arctic specialists, including marine scientist Prof Carlos Duarte, director of the Oceans Institute at the University of Western Australia.

In early April, Duarte warned that the Arctic summer sea ice was melting at a rate faster than predicted by conventional climate models, and could be ice free as early as 2015 – rather than toward the end of the century, as the UN Intergovernmental Panel on Climate Change (IPCC) projected in 2007. He said:

"The Arctic situation is snowballing: dangerous changes in the Arctic derived from accumulated anthropogenic green house gases lead to more activities conducive to further greenhouse gas emissions. This situation has the momentum of a runaway train."

Duarte is lead author of a paper published last year in Nature Climate Change documenting how "tipping elements" in the Arctic ecosystems leading to "abrupt changes" that would dramatically impact "the global earth system" had "already started up." Duarte and his team concluded: "We are facing the first clear evidence of dangerous climate change."

New NASA satellite imagery from March 2013 reveals massive cracks in ice connecting Beaufort Gyre region to Alaska

New research suggests that the Arctic summer sea ice loss is linked to extreme weather. Rutgers University climate scientist Jennifer Francis points to the phenomenon of "Arctic amplification," where:

"The loss of Arctic summer sea ice and the rapid warming of the Far North are altering the jet stream over North America, Europe, and Russia. Scientists are now just beginning to understand how these profound shifts may be increasing the likelihood of more persistent and extreme weather."

Extreme weather events over the last few years apparently driven by the accelerating Arctic melt process – including unprecedented heatwaves and droughts in the US and Russia, along with snowstorms and cold weather in northern Europe – have undermined harvests, dramatically impacting global food production and contributing to civil unrest.

US national security officials have taken an increasing interest in the destabilising impact of climate change. In February this year, the US Department of Defense (DoD) released its new Climate Change Adaptation Roadmap, which noted that global warming will have:

"... significant geopolitical impacts around the world, contributing to greater competition for more limited and critical life-sustaining resources like food and water."

The effects of climate change may:

"Act as accelerants of instability or conflict in parts of the world... [and] may also lead to increased demands for defense support to civil authorities for humanitarian assistance or disaster response, both within the United States and overseas … DoD will need to adjust to the impacts of climate change on its facilities, infrastructure, training and testing activities, and military capabilities."

The primary goal of adaptation is to ensure that the US armed forces are "better prepared to effectively respond to climate change" as it happens, and "to ensure continued mission success" in military operations – rather than to prevent or mitigate climate change.

While the DoD is also concerned about the Arctic, the focus is less on risks than on opportunities:

"The Department is developing cooperative partnerships with interagency and international Arctic stakeholders to collaboratively address future opportunities and potential challenges inherent in the projected opening of the Arctic."

Arctic "stakeholders" include US, Russian, Canadian, Norwegian and Danish energy firms, which are scrambling to exploit the northern polar region's untapped natural wealth. The region is estimated to hold a quarter of the world's remaining undiscovered oil and gas reserves, sparking concerted efforts by these countries to expand their Arctic military presence.

The US Homeland Security Department's Climate Change Roadmapreleased last year raised similar issues, warning that climate change "could directly affect the Nation's critical infrastructure," as well as aggravating "conditions that could enable terrorist activity, violence, and mass migration."

On the Arctic, the report highlights the imperative to protect US resource interests by increasing regional military penetration:

"Melting sea ice in the Arctic may lead to new opportunities for shipping, tourism, and resource exploration, but the increase in human activity may require a significant increase in operational capabilities in the region in order to safeguard lawful trade and travel and to prevent exploitation of new routes for smuggling and trafficking."

A public statement in response to news of the White House's Arctic briefing released on Tuesday by the UK-based Arctic Methane Emergency Group (AMEG) – a group of international climate scientists – called on governments to recognise that the dramatic loss of summer sea ice in the Arctic would amplify the types of extreme weather events that have already affected the world's major food basket regions, undermining global food production for the foreseeable future with serious consequences for international security.

The group, which includes among its founding members leading Arctic specialists such as Prof Peter Wadhams, head of the Polar Ocean Physics Group at Cambridge University, stated that:

"The weather extremes from last year are causing real problems for farmers, not only in the UK, but in the US and many grain-producing countries. World food production can be expected to decline, with mass starvation inevitable. The price of food will rise inexorably, producing global unrest and making food security even more of an issue."

The AMEG statement adds that governments should consider geoengineering techniques – large-scale technological interventions in the climate system – to "cool the Arctic and save the sea ice" in order to avert catastrophe. Critics point out, however, that untested geoengineering technologies could have damaging unintended impacts on ecosystems, and that a regulatory framework is needed before embarking on major projects.

Dr Nafeez Ahmed is director of the Institute for Policy Research & Development and author of A User's Guide to the Crisis of Civilisation: And How to Save It.

http://www.guardian.co.uk/environment/earth-insight/2013/may/02/white-house-arctic-ice-death-spiral

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