Previous articles in this series have reviewed recent research on methane sources from beneath permafrost and ice sheets. Part 1 looked at subcap fossil methane seeps in Alaska; Part 2 provided a perspective for the size of these seeps in relation to other natural and human sources; and Part 3 looked at potential methane sources resulting from the withdrawal of glaciers and ice sheet. In this final section, I will try to make estimates of what subcap methane emissions may mean for future climate change; more as a speculative basis for discussion rather than an authoritative prediction. Firstly, though, I will argue for a role for subcap methane emissions on the East Siberian Arctic Shelf (ESAS).
As permafrost thaws, methane is released as the vegetable matter in the soils decomposes. This methane bubbles to the surface in lakes and ponds and accumulates under the ice in the wintertime. New research has shown that the most vigorous methane seeps in Alaska are fed also by methane emitted by thermal decomposition of organic matter in deeper and much older sediments. Continuous permafrost acts as a top seal to this fossil methane, preventing it from reaching the surface and, as global warming melts and perforates this cap, we can expect the pent-up gas to be released more quickly. This source of methane, released from traps under the permafrost, is a potential third source of methane feedback in the Arctic, in addition to permafrost soils and methane hydrates.
"My other piece of advice, Copperfield," said Mr. Micawber, "you know. Sea-wall height twenty feet, maximum storm surge nineteen feet six inches, result happiness. Sea-wall height twenty feet, maximum storm surge twenty feet six inches, result misery. The blossom is blighted, the leaf is withered, the god of day goes down upon the dreary scene, and — and in short you are for ever flooded."
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Posted on 26 October 2012 by Andy Skuce &
From 1989 to 2002, several large US companies, including the oil companies Exxon and the US subsidiaries of Shell and BP, sponsored a lobbying organisation called the Global Climate Coalition (GCC), to counter the strengthening consensus that human carbon dioxide emissions posed a serious threat to the Earth’s climate. As has been documented by Hoggan and Littlemore and Oreskes and Conway, the GCC and its fellow travellers took a leaf out of the tobacco industry’s playbook and attempted to counter the message of peer-reviewed science by deliberately sowing doubt through emphasizing uncertainties and unknowns. The climate scientist Benjamin Santer accused the GCC of deliberately suppressing scientific information that supported the IPCC consensus.
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Posted on 4 October 2012 by Andy Skuce &
A recent modelling experiment shows that climate change feedbacks from thawing permafrost are likely to increase global temperatures by one-quarter to a full degree Celsius by the end of this century. This extra warming will be in addition to the increase in temperature caused directly by emissions from fossil fuels. Even in the unlikely event that we were to stop all emissions in the near future, this permafrost climate feedback would likely continue as a self-sustaining process, cancelling out any future natural draw-down in atmospheric carbon dioxide levels by the oceans or vegetation. Avoiding dangerous climate change by reducing fossil-fuel emissions becomes more difficult once permafrost emissions are properly considered.
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Posted on 28 September 2012 by Andy Skuce &
Skeptical Science readers may already be familiar with the dismal performance of the Canadian Federal Government on climate change. The Canadian contributors to Skeptical Science expressed our concerns about the erosion of our country's science for political ends in a blog post here in March of this year: PMO Pest Control: Scientists. We have also run a number of posts on the rapid development of the oil sands, for example: Tar Sands Oil - An Environmental Disaster and; Alberta’s bitumen sands: “negligible” climate effects, or the “biggest carbon bomb on the planet”?. This summer, Canadian scientists have been taking their protest to the street and last week there was a rally in Victoria, British Columbia.
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Posted on 16 August 2012 by Andy Skuce &
One of the perennial Skeptical Science top ten climate myths is “There is no consensus” (currently at number 4 in popularity). Consensus means the elements of knowledge that research scientists tend not to discuss or actively investigate any more. Consensus is the stuff that fills textbooks and is the established knowledge that teachers try to cram into high school and undergraduate students’ heads. It doesn’t mean an impregnable bastion of knowledge—there are many well-known examples of consensus-changing revolutions in the history of science—and even school textbooks have to get updated every now and then.
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Posted on 15 June 2012 by Andy Skuce &
It is not news that people are polarized over their assessment of the risks posed by climate change. But is it true that the most polarized people are those who are more scientifically literate? Counter-intuitive though it may seem, the answer is: Yes, it is. This is the result of a recent article by Dan Kahan and six colleagues in Nature Climate Change (henceforth, the Kahan Study). This study has received a lot of attention, with blog articles, for example in The Economist, Mother Jones and by David Roberts at Grist.
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Posted on 28 April 2012 by Andy Skuce &
*The climate effects of bitumen development are significant once viewed in the perspective of probable emissions over the rest of this century.
*The climate impact of coal consumption is greater than that of bitumen, particularly when non-mineable coal is considered.
*Accelerated expansion of bitumen extraction will make climate mitigation efforts much more difficult.
*Because of its high carbon emissions and high extraction costs, further bitumen development would not be viable if stringent global emissions policies were adopted.
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Posted on 11 April 2012 by Andy Skuce &
Sudden spikes in global temperatures that occurred 50-55 million years ago were caused by thawing of permafrost in Antarctica and northern high latitudes, according to recent research. The trigger for this sudden destabilization was a variation in orbital configurations that resulted in warmer polar summers. This model also provides an analogue for the releases of carbon from modern permafrost caused by current man-made global warming. Modern permafrost volumes are smaller than the estimates for those of 55 million years ago, but will nevertheless amplify the climatic effect of fossil fuel consumption and will provide continuing warming feedbacks for centuries after human emissions cease.
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Posted on 6 April 2012 by Andy Skuce &
Fifty million years ago, during the Eocene Epoch , the world had a very different climate, with temperatures much higher than today's, especially at the poles. This hothouse climate was caused mainly by CO2 levels that were twice as high, or more, than now. On our current emissions trajectory, we could recreate the chemistry of the hothouse atmosphere before the end of this century, with potentially drastic consequences for our climate.
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Posted on 11 March 2012 by Andy Skuce &
Effective action for solving Victorian London's sewage crisis was put off for decades, due to chaotic governance, concerns about financing, the interference of vested interests and the complacency and inertia of central government. Once the ill effects appeared underneath the politicians’ noses, a lasting solution was quickly deployed. The modern challenge of finding the political will to deal with climate change is analogous, although there are additional factors that make fixing the climate problem much more difficult.
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Posted on 11 March 2012 by Andy Skuce &
Nobody comes into this world with a fully-formed opinion on anthropogenic climate change. As we learn about it, we change our minds. Sometimes, changing your mind can be easy and quick; sometimes it’s hard and slow. This is an anecdotal and subjective account of the author’s changes of mind.
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Posted on 30 December 2011 by Andy Skuce &
Here is a translation of recent article (December 25th, 2011) in the French newspaper Le Monde by science journalist Stéphane Foucart. He reports on a talk that Michael Mann gave at the 2011 AGU Fall Meeting in San Francisco, in which Mann introduces his forthcoming book The Hockey Stick and the Climate Wars: Dispatches from the Front Lines. Foucart interviews Mann and discusses the background of the Hockey Stick and Climategate controversies. What is refreshing is the absence of the false balance, both-sides-of-the-story, style of reporting that is found so often in English language newspapers.
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Posted on 1 December 2011 by dana1981 & Andy Skuce
As Andy recently discussed, the International Energy Agency (IEA) has published the World Energy Outlook 2011 (WEO11), which incorporates the most recent data on global energy trends and policies, and investigates the economic and environmental consequences of three scenarios over the 2010 to 2035 time period:
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Posted on 16 November 2011 by Andy Skuce &
If we don’t change direction soon, we’ll end up where we’re heading
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Posted on 21 October 2011 by Andy Skuce &
A paper submitted for peer review by the Berkeley Earth Surface Temperature study (BEST) finds that urban heating has an influence on global temperature trends that is “nearly negligible” and that what effect has been observed is even slightly negative, which is to say that temperature trends in urban areas are actually cooler than the trends measured at rural sites, and that the Earth's land surface has warmed approximately 1°C on average since 1950.
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Posted on 17 September 2011 by Andy Skuce &
This blog post is the intermediate-level rebuttal to the climate myth “Underground temperatures control climate”.
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Posted on 12 August 2011 by Andy Skuce &
This is the third and final article in the series on climate contrarian Matt Ridley. Here are Parts One and Two.
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Posted on 7 August 2011 by Andy Skuce &
This is the second of three articles on the climate contrarian Matt Ridley. Part One is here.
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Posted on 30 July 2011 by Andy Skuce &
This is a three-part series on science writer, businessman and climate contrarian Matt Ridley. The first section looks at his science books and is critical of his latest book, The Rational Optimist; the second scrutinizes one of his blog posts on climate change and shows that his avowed lukewarmer stance is built on shaky scientific foundations; the final part examines Ridley’s history as a businessman, drawing parallels between his role in the credit crunch and his approach to climate change.
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Posted on 14 July 2011 by Andy Skuce &
Like many an aging baby boomer, the Earth is starting to bulge at the waist and is getting thinner on top. In the Earth’s case this isn’t due to a weakness for drinking beer or due to an inherited tendency towards male pattern baldness. Rather, it is because of climate change. As the big ice sheets in Greenland and Antarctica thaw, the melt water is distributed throughout the world’s oceans, causing mass to move away from the poles.
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Posted on 24 February 2011 by Andy Skuce &
The document entitled 'Carbon Dioxide and Earth's Future: Pursuing the Prudent Path', referenced in the "skeptic" scientist letter to US Congress, makes the claim that rising CO2 concentrations have "actually been good for the planet" because of the fertilization effect of CO2. Although it is true that there has been a measurable CO2 fertilization effect, particularly in the tropics (see this video seminar), this is only one factor that will influence the response of the global carbon cycle to climate change. It's instructive to look at some important factors that are not mentioned in The Prudent Path.
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Posted on 15 February 2011 by Andy Skuce &
"
The climate system is an angry beast and we are poking it with sticks" - Wallace Broecker
The belly of Broecker’s climate beast is surely the global carbon cycle. Currently, the beast is digesting about half of our fossil-fuel CO2 emissions, acting as a major stabilizing influence on the climate, a negative feedback. But as Professor David Archer warns us in his latest book, The Global Carbon Cycle, the carbon cycle behaves unpredictably in different circumstances and over different timescales. For example, during the Paleocene-Eocene Thermal Maximum (PETM), it acted to bring things back to the then hothouse normal after a massive belch of carbon into the atmosphere. At other times, it amplified small temperature perturbations into climate events that changed the face of the planet, as it did in the ice age cycles, the period we are still currently in. Humans are administering a perhaps PETM-scale dose of carbon into the atmosphere during a time when the global carbon cycle has acted as an amplifier rather than a damper. Ominously, Archer tells us, the planet’s reservoirs of carbon in the form of peat, gas hydrates and rain-forest carbon are now probably as charged up as they can be. That's some beast; some stick.
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Posted on 6 February 2011 by Andy Skuce &
A short paper by Simon Lewis, Paulo Brando and three co-authors, just published in Science Magazine, reports on the 2010 drought in the Amazon Basin. This drought occurred only a few years after the exceptional drought of 2005, which was supposed to have been a one-in-a-hundred-year event. The paper presents evidence that last year's drought was both more severe and more extensive than the earlier one.
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Posted on 26 December 2010 by Andy Skuce &
"Space," it says, "is big. Really big."
The Hitchhiker's Guide to the Galaxy, by Douglas Adams
If the AGU Fall Meeting had to be summed up in one word, that word would surely have to be big. There were over 19,000 people attending and many thousands of talks and poster presentations. The Scientific Program guide is 560 pages long with each page listing about thirty presentation titles. I doubt that anyone (except maybe some hapless AGU proof-reader) has been able to read this mostly verb-free text from beginning to end. Fortunately, the AGU provides an online scheduling tool that allows you to search the program for keywords and set up a personalized itinerary; but the process of presentation selection remains rather random. Everyone experiences a different meeting.
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Posted on 25 October 2010 by Andy Skuce &
The observatory near the summit of the Mauna Loa volcano in Hawaii has been recording the amount of carbon dioxide in the air since 1958. This is the longest continuous record of direct measurements of CO2 and it shows a steadily increasing trend from year to year; combined with a saw-tooth effect that is caused by changes in the rate of plant growth through the seasons. This curve is commonly known as the Keeling Curve, named after Charles Keeling, the American scientist who started the project.
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Posted on 27 August 2010 by Andy Skuce &
The solid Earth contains a huge quantity of carbon, far more than scientists estimate is present in the atmosphere or oceans. As an important part of the global carbon cycle, some of this carbon is slowly released from the rocks in the form of carbon dioxide, through vents at volcanoes and hot springs. Published reviews of the scientific literature by Moerner and Etiope (2002) and Kerrick (2001) report a minimum-maximum range of emission of 65 to 319 million tonnes of CO2 per year. Counter claims that volcanoes, especially submarine volcanoes, produce vastly greater amounts of CO2 than these estimates are not supported by any papers published by the scientists who study the subject.
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