Cold moments

arcticmethane.jpgMore data on the state of the methane hydrates on the Siberian shelf emerged during the American Geophysical Union’s Fall meeting in San Francisco this week. At a press conference covering recent work in the Arctic, Igor Semiletov, the leader of the team working on the Yakov Smirnitsky last (Arctic) summer, told reporters:

“The concentrations of the methane were the highest ever measured in the summertime in the Arctic Ocean,” Semiletov said. “We have found methane bubble clouds above the gas-charged sediment and above the chimneys going through the sediment.” [Science Daily, e! Science News]

A reporter at the press conference, who blogs at A Change In The Wind, asked Semiletov if the increase in methane release his team had discovered constituted “a global emergency”. In his blog entry he writes:

[…] his struggle with the question was evident. I tracked him down later, and asked if he felt he was the wrong person to be answering such a huge question. He admitted his discomfort, but said he thought it was the best question he was asked, and insisted:

“I am the person responsible for this research, and I think we have to tell people that something is happening now with the subsea permafrost.”

Why? A Change In The Wind explains:

Semiletov thinks that if just 1% of the ESAS methane is released, it will push total atmospheric methane up to 6 parts per million, and cites researchers such as David Archer in arguing that this would push us past the point of no return, towards runaway global warming.

Six ppm methane is a little over three times the current level, and with a global warming potential of 25, is equivalent to 150 ppm CO2, or 50 years worth of current annual CO2 emissions. There’s no reference to any time scale for this release, but the possibility should be enough to ring alarm bells — and loudly.

[There’s plenty of other Arctic/climate related material to blog from the Fall AGU meeting, and I’ll get to some of it soon, but for the time being Christmas shopping looms…]

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Six Degrees

This posting is based on a Waikato Times column written in July.

The Royal Society in the UK awarded its 2008 science writing prize to Mark Lynas for his global warming book Six Degrees: Our Future on a Warming Planet. I found the book telling when I read it last year, and it was good to see it receive this confirmation.

Lynas’s first book High Tide, published in 2004, grew out of three years visiting parts of the globe where the signs of global warming were becoming evident – Alaska, Tuvalu, Mongolia, Peru, the US.  Six Degrees had a different genesis. It is the result of many months in the Radcliffe Science Library at Oxford trawling through scientific journals to find the peer-reviewed papers on which the book is entirely based.  The source material ranges from computer model projections to studies of climate in the past. Lynas is not a scientist, but he makes it his business to adequately understand and interpret what the scientists have written in their specialist fields.

Sceptics often scoff at computer models as somehow fiddled in advance, but Lynas points out that they are based not on subjective judgements by their constructors but on the fundamental laws of physics.  They have grown increasingly sophisticated and the insight they offer into likely future conditions on the planet is something humanity has never had access to before.  One check on their accuracy is ‘hindcasting’ the 20th century, and some of the most powerful recent models have done this with almost unerring accuracy.  Not that Lynas suggests that they are infallible in their forecasts.

Six Degrees is a highly readable narrative for the general reader, tracking through what changes can likely be expected from each degree of global warming from one degree through to six degrees, the upper limit for worst case scenarios.

Even at what may seem comparatively low rises of one or two degrees centigrade he finds plenty to cause alarm. A few of his examples:  possible desertification and abandonment of agriculture over millions of square kilometres in the US, an extremely hot and drought-ridden Mediterranean Europe, an ice-free Arctic ocean with implications still difficult to understand, the bleaching and likely death of many coral reefs, major loss of food production in India, serious population displacement in Bangladesh. On through three and four degrees the book points to desertification intensifying in many places, water supply severely declining in Pakistan, the Amazon rainforest dying, far more of Australia burning and suffering serious drought, the West Antarctic ice sheet facing collapse, sea levels rising threateningly. Five and six degrees hardly bear contemplating as the possibility is faced of methane hydrates on subsea continental shelves becoming destabilised and venting into the atmosphere, adding an enormous feedback to global warming.

As a writer for the general public Lynas doesn’t shrink from putting emotional depth into his analysis.  He explains in a Guardian column: “If I’ve read a paper about coral bleaching or precipitation trends in the Sahel, I need to be able to describe what this means in the real world – grey weed creeping over once-vibrant coral reefs, and Sudanese herders struggling to feed their children as their livestock starves around them and a dust-storm looms on the horizon.”   However he sees his first duty as accurately representing what he has read in the scientific literature.   The Royal Society judges are clear that he has met this test. They state that the book provides a good overview of the latest science on the issue. An interesting response came from  Eric Steig, one of the contributing scientists to the Real Climate website, when he reviewed the book in Conservation Magazine. Initially he had assumed from news reports that the book was alarmist and probably not worth reading; however, after reading it he reported it firmly based on published scientific literature and nowhere exceeding those bounds. Alarming, yes, but not alarmist.

There is no escaping that the science is alarming. That is why this issue is of such overwhelming importance. Yet like most writers on the subject Lynas hopes that we can yet avoid the worst prospects. There is already unavoidable further warming ahead of between 0.5 and 1 degree Celsius, but it is possible that we might manage a ‘safe landing’ within the 1-2 degree corridor if appropriate action is begun now to drastically reduce greenhouse gas emissions.

This is the point at which the question moves from science into the realm of the political. We largely know how the needed reductions could be achieved.  The question is whether we find the collective will to do it.  The fact that that is still an open question indicates the full reality of the science has not dawned for enough of us.   Books like Six Degrees need wide readership. Hopefully the Royal Society prize will assist that.

It is worth noting that Six Degrees was published in America by National Geographic, which has also made a television documentary based on the book and broadcast on the National Geographic channel internationally. On a lighter note Lynas also achieved minor fame as a somewhat younger man in 2001 by throwing a cream pie at Bjorn Lomborg, the ‘sceptical environmentalist’. “I wanted to put a Baked Alaska in his smug face in solidarity with the native Indian and Eskimo people in Alaska who are reporting rising temperatures, shrinking sea ice and worsening effects on animal and bird life.”

In the heat of the (Arctic) night

LWOct2008.gif Time for an Arctic update and a bit of “original” research. There’s been quite a bit of polar news around, and a rapid freeze-up is underway in the Arctic – so rapid that some are declaring that the sea ice is “back to normal” for the time of year, based on this graph from the Arctic Regional Ocean Observing System in Norway, which shows sea ice area climbing up towards to the average for 1979-2007, within one standard deviation (the grey area). On the other hand, if you look at the equivalent graph at Cryosphere Today, you’ll see that ice area is 1.25m km2 below the average – which in CT’s case is 1979-2000. So the ice is approaching normal, only if you define “normal” as including the significant ice reductions over the last seven years. How encouraging. But this autumn’s freeze-up has been pretty rapid. Does that mean that it’s been unusually cold up there? I thought I’d take a look…

Continue reading “In the heat of the (Arctic) night”

Something in the air (methane mystery)

arcticmethane.jpgAtmospheric methane levels “shot up” in 2007, according to a paper in this week’s Geophysical Research Letters (MIT news release — Rigby, M., R. Prinn, et al (2008), Renewed growth of atmospheric methane, Geophys. Res. Lett., doi:10.1029/2008GL036037, in press. PDF here for AGU members.). This confirms NOAA’s announcement in April that methane levels were on the increase after a decade of stability, but adds a new twist to the data.

One surprising feature of this recent growth is that it occurred almost simultaneously at all measurement locations across the globe. However, the majority of methane emissions are in the Northern Hemisphere, and it takes more than one year for gases to be mixed from the Northern Hemisphere to the Southern Hemisphere. Hence, theoretical analysis of the measurements shows that if an increase in emissions is solely responsible, these emissions must have risen by a similar amount in both hemispheres at the same time.

A rise in Northern Hemispheric emissions may be due to the very warm conditions that were observed over Siberia throughout 2007, potentially leading to increased bacterial emissions from wetland areas. However, a potential cause for an increase in Southern Hemispheric emissions is less clear.

A possible explanation might be a global reduction in the amount of hydroxyl free radical (OH) in the atmosphere. OH “mops up” methane (and other stuff), and is sometimes called the atmosphere’s cleaner or “detergent”. Unfortunately, measuring atmospheric OH is difficult.

“The key thing is to better determine the relative roles of increased methane emission versus any decrease in the rate of removal,” Prinn said. “Apparently we have a mix of the two, but we want to know how much of each” is responsible for the overall increase.It is too early to tell whether this increase represents a return to sustained methane growth, or the beginning of a relatively short-lived anomaly, according to Rigby and Prinn.

Any increase in atmospheric methane is not good news. A possible reduction in OH is also disturbing, because it might indicate that pollution (from all sources, methane, industry, coal burning etc) is beginning to overwhelm the atmosphere’s ability to cleanse itself. Both together would be very bad news indeed.

[Update: Comments from a CSIRO scientist and co-author here.]

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Across the university

My computer asked me to update iTunes this morning, and with the latest version installed a whim took me to the Music Store, then into iTunes U – Apple’s rather US-centric title for a huge collection of university lectures and podcasts, audio and video, from academic institutions around the world. There’s stuff from Otago, Yale, Stanford, Cambridge – and recently added, lectures from my alma mater. If you use iTunes and have an account at the Music Store (you can open an account by giving them a credit card number, but do not then have to buy anything) there is a huge amount of free material available for download. I have a couple of lectures from University of California’s Santa Barbara campus (UCTV) to watch: James Hansen giving the Nierenberg lecture at the Scripps Oceanographic Institute, and a lecture on methane hydrates. It’s a great resource – but be warned, you need lots of bandwidth to take advantage of the videos…

If you have any favourites from iTunes U, let us know in the comments.

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