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Comments 43151 to 43200:

43151. TonyW at 19:35 PM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       This article was linked on another site. The point was made that it doesn't cover free methane, only hydrates. The commenter had this to say:"The warning [of catastrophic release] is about free methane on the ESAS dissociated by geothermal flux and submersion of the shelf over the last 8,000 years and subsequent warming that has degraded the permafrost cap and the methane is now finding pathways to escape from the seabed to the atmosphere. No hydrate dissociation is required. 1 to 2% of the methane on the ESAS is enough to cause catostrophic warming and that is all free methane, not hydrates.Also, the Hydrate Stability Zone is now down to a depth of 1400 meters. The maximum depth of the ESAS is 100 meters, with an average depth of 50 meters.The latest research is showing not only is the degradation of the relic permafrost providing pathways, but seismic activity on the ESAS is creating fissures that are providing pathways for free methane to escape."Any response, Chris?
43152. Paul D at 18:54 PM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       I think the Richard Alley course also starts in September.

43153. BaerbelW at 17:23 PM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       Richard - there is a course which might fit what you are looking for and it starts on August 12:

       Climate Change - University of Melbourne
       "This course develops an interdisciplinary understanding of the social, political, economic and scientific perspectives on climate change."
       Instructors: Professor Jon Barnett, Professor John Freebairn, Professor David Jamieson, Dr. Maurizio Toscano and Rachel Webster

       And, while on the subject of additional courses in this topic area, there is one more I already signed up for. It starts on Sept. 16:

       Energy, the Environment and Our Future - Penn. State University
       "Get Rich and Save the Earth…Or Else! Learn about the past, present, and possible futures of human energy use."
       Instructor: Richard B. Alley

43154. Richard Komorowski at 15:31 PM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       Having studied and written about climate change for quite a while, I would call myself knowlegable, although certainly not an expert.

       I too am nearing the end of this course (just the final to go). Have I learned anything fundamentally new to me? Probably not. On the other hand, I have learned a great deal about how everything fits and interacts together, so all in all I understand the science of climate change better now than I did ten weeks ago.

       I would recommend this course for anyone who is looking for a good overview of the subject. It is an excellent foundation for anyone who wants to progress towards a deeper understanding of the many branches of climate science.

       For myself, I would love to see a course geared towards the politics, economics and sociology of climate change.

43155. Doug Hutcheson at 15:25 PM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Thanks for this article. I am now less alarmed by Arctic methane than I was.

       The point, however, is moot: even if the was a likelihood of devastating, rapid injections of methane into the atmosphere, there is precious little we could do about it. The future under BAU CO₂ emissions is projected to be so bad that adding a methane menace does not materially affect the outcome for our civilisation, or for our species. Homo Stupidus stupidus.

43156. One Planet Only Forever at 14:09 PM on 4 August 2013
       2013 SkS Weekly News Roundup #31B
       

       The focus of the Times Editorial on planet warming and climate change can be broadened. The concern is the sustainability of the economy. Fundamentally, any economic activity that relies on burning non-renewable resources is not sustainable. The accumulating impacts make it even less sustainable by diverting resources to deal with the climate change consequences.

       So, if the concern really is to develop an economy that can sustainably grow the burning of fossil fuels has to end sooner rather than when the economy fails. The current economy is actually struggling because of all the activity within it that is simply not sustainable.

43157. Rob Honeycutt at 11:37 AM on 4 August 2013
       An accurately informed public is necessary for climate policy
       

       Terranova...  If human activities are responsible for >50% of warming, is that dangerous?

43158. JasonB at 11:17 AM on 4 August 2013
       2013 SkS Weekly News Roundup #31B
       

       Forrest,

       I did a quick test for "Industrialised Countries" (red flag there — trying to pretend that everyone else will continue BAU will of course reduce the impact of the actions of a subset of countries), 100% reduction, and 3°C degrees sensitivity, and it said that by 2100 the consequence would be a reduction of 0.278°C compared to A1B (second red flag, since they're really advocating A1FI, and A1B doesn't really equate to "do nothing about climate change", which is precisely what they're trying to suggest).

       The IPCC temperature change for 2090-2099 relative to 1980-1999 for each scenario shows a range of -1.0°C relative to A1B (for B1) up to +1.2°C (for A1FI). That's a difference of 2.2°C depending on emissions scenario, and even B1 with its 1.0°C drop relative to A1B isn't as agressive as their purported scenario from what I can see.

       If it was actual science rather than simply propaganda I'd expect them to explain why they think their results are so small compared to what people might expect rather than just present it as "fact" with no more to say about it.

43159. David Kirtley at 11:14 AM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       I took this course too and thought it was very good.  I highly recommend it.  My next Coursera class will be on Statistics.

43160. Forrest at 10:08 AM on 4 August 2013
       2013 SkS Weekly News Roundup #31B
       

       Encouraging to see the NY Times editorial.  However, the comments in the Times include a reference to a "Handy-Dandy Carbon Tax Temperature-Savings Calculator" created by the CATO Institute which claims to calculate the temperature impact in the year 2100 of reducing CO2 emissions by a user-selected amount for the next 50 years.  

       The comment says that eliminating all CO2 for the next 50 years will mean global temperature is 0.28 degrees C lower than it would have been otherwise.  The commenter claims this is equivalent to moving 10 miles south.  This makes no sense.  Assuming 12,000 miles from the pole to the equator, then 0.28 degrees per 10 miles means an average temperature difference of 336 deg C between the pole and equatotor.  

       Would someone more knowledgable than I take a look at the calculator and comment on whatever other "issues" it may have?

43161. Composer99 at 09:28 AM on 4 August 2013
       It's not bad
       

       without appropriate context noting studies like this distorts our necessary perception and responses to climate change

       You mean such as, say, omitting the peak season for influenza in the United States from consideration?

       With studies such as this, or news articles such as this, it appears much of the seasonal mortality in winter is the result of not the weather, but of the seasonal variation in influenza circulation.

       Or perhaps you mean, say, referring strictly to seasonal trends in mortality in a single country rather than from a global perspective?

43162. Sceptical Wombat at 09:04 AM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       Also starting in September is a MOOC on Solar Energy being run by Delft University of Technology in the Netherlands on EdX.  This looks like a fairly technical course.

43163. Daniel Bailey at 09:01 AM on 4 August 2013
       It's not bad
       

       Hmm.  Available evidence shows that it is the human adaptation to weather extremes that is key in limiting mortality.  Evidence for that assertion:

       "Adaptation measures have prevented a significant increase in heat-related mortality and considerably enhanced a significant decrease in cold-related mortality. The analysis also suggests that in the absence of any adaptive processes, the human influence on climate would have been the main contributor to both increases in heat-related mortality and decreases in cold-related mortality."

       and

       "With regard to heat-related mortality, projected future increases in the frequency and intensity of heat waves may exert a stress beyond the adaptive limits of the population."

       Causes for the recent changes in cold- and heat-related mortality in England and Wales
       Nikolaos Christidis, Gavin C. Donaldson, Peter A. Stott; Climatic Change, October 2010

        

       That's called supporting an assertion with evidence.

43164. John Hartz at 07:55 AM on 4 August 2013
       It's not bad
       

       @Ray Coleman #352

       You blithely assert, 

       Intermittent Heatwave 'costs' in terms of mortality are insignificant compared to the 'benefit' of a warmer continental US.

        Please provide documentation to support your statement.

43165. Roy Coleman at 07:06 AM on 4 August 2013
       It's not bad
       

       "Increased deaths to heatwaves - 5.74% increase to heatwaves compared to 1.59% to cold snaps (Medina-Ramon 2007)"

       SO? This has no context in terms of the general population mortality. The CDC figures on US death rates (2007-8) are quite clear, 900 more people per million die in cold weather, at temperatures below 12 degrees, that's in excess of 250000 people annually! Intermittent Heatwave 'costs' in terms of mortality are insignificant compared to the 'benefit' of a warmer continental US. You must excuse me but without appropriate context, noting studies like this distorts our necessary perception and responses to climate change.

        

43166. Leland Palmer at 04:49 AM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       By the way, even if most of the methane doesn't make it into the atmosphere, it could still do the biosphere major harm via ocean acidification, as it oxidizes into CO2 in the oceans.

       I seem to recall seeing a modeling paper of this phenomenon in the Arctic ocean, which predicts that chronic methane release from the hydrates would overwhelm the oceans ability to absorb and oxidize the methane, and lead to more direct venting of methane to the atmosphere.

       There are also suspicions that anoxic oceans could increase their production of NOx, I think.

       As gws said, the atmospheric chemistry effects of methane release have to be considered- but so do the oceanic chemistry effects.

       In his book "Under a Green Sky" Peter Ward talks about the truly catastrophic effects of massive methane release on the oceans, including anoxia and proliferation of strange bacteria. We're not there yet, and have a long way to go before things get that bad.

       But, once it starts, could we stop the process? 

43167. gws at 04:26 AM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       I would like to emphasize a point made by Leland, namely that further increasing atmospheric methane will have significant impacts on atmospheric chemistry. Increased atmospheric methane tends to decrease OH radical abundance and increase ozone abundance under current NOx availability, which increases atmospheric pollutant lifetimes and further stresses ecosystems (via ozone).

       A review paper by Wuebbles and Hayhoe can be found here. The potential changes described in the more recent Isaksen paper cited by Leland are indeed "alarming", wherefore the atmospheric chemistry community does place a priority on how methane sources may change, including due to AGW factors.

       Humans have so far approx. trippled the amount of methane in the troposphere (particularly via meat consumption, rice cultivation, and organic waste dumping; aka via boosting methanogenesis, but also via fossil fuel extraction and use), and more adverse atmospheric chemistry effects of that have so far not occurred due to a rather stable cleansing capacity of our atmosphere (supported by our simultaneous pollution of it with NOx). But as its response is non-linear, an out-of-control increasing methane source strength could be devastating, regardless of its speed.

       Meaning, even if the chances of a rapid release are remote from today's point of view, if there is a large reservoir that could be released to the atmosphere, we should be very concerned about that possibility and take any and all preventive action to stop it from actually doing so, regardless of the speed of release.

43168. John Mason at 02:52 AM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Michael, #21,

       I agree to an extent - what we are doing here WRT atmospheric composition may be unprecedented in the entire Phanerozoic in terms of rate. On that basis, Chris, are we not comparing apples and oranges? It may be completely irrelevant that nothing like the things Wadhams is concerned about appear to have occurred over the past few glacial-interglacial cycles: nothing within them, apparently at the very l;east, occurred so quickly. One to consider!

43169. michael sweet at 02:24 AM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Glenn,

       Since the forcing today is much greater today than in the PETM (at least 10 times greater), why do you suppose the methane releases during the PETM are the maximum speed possible?  Since the forcing is so much greater, it stands to reason that the methane release will also be much faster.  Can you explain your argument?

43170. acjames76 at 01:31 AM on 4 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       I started the course near the end, but it will be worthwhile starting it again.  The instructors say:

       We are planning a second offering of Climate Literacy, likely to start in late September. If you have friends, family, or colleagues you think would like to participate, they can currently click the "Add to Watchlist" button on Coursera. Soon there will be a button to actually register for the second offering.

43171. Leland Palmer at 01:25 AM on 4 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Hi Glenn Tamblin at post # 18-

       It's true that methane hydrate dissociation is an endothermic process and that there may be a rate limit to its release. 

       A lot of the total methane release from the hydrates depends on the total methane hydrate inventory, though - the total amount that exists on the earth. 

       Estimates, as you know, range from about 400 billion metric tons to about 77 trillion metric tons - roughly 440 to 85,000 cubic kilometers.

       That's a big range, Glenn.

       Archer and his collaborators estimate we have something like 4,000 cubic kilometers of methane hydrate, while Dickens and his collaborators talk about a consensus estimate of around 10,000 to 20,000 cubic kilometers. I've seen a paper on the End Triassic which talks about roughly 13,000 cubic kilometers released, rather slowly, which in my mind casts doubt on the lower estimates of total hydrate inventory.

       So, first point, we don't know how much hydrate is down there, on the continental shelves. Multiply a low rate of dissociation by a large hydrate inventory, and one can arrive at a high total methane release. This alone argues that complacency is contraindicated.

       Since we are coming out of a series of ice ages, with low ocean temperatures promoting hydrate stability, we could in fact have massive amounts of hydrate in the global hydrate inventory. And hydrate deposits which are uneconomically thin or scattered and useless to the fossil fuel corporations, not worth mapping, really- might release methane even more rapidly than the economically valuable deposits, because of their scattered and porous nature- especially if they are shallow deposits.

       Some of the papers I've looked at  on hydrate dissociation assume that the convoluted three dimensional hydrate deposits, full of chimneys large enough to show up quite well on sonar, will act like a one or two dimensional model spread uniformly over a two dimensional surface- a highly questionable assumption. Complicated real world processes like convection, convoluted geometry, and chimneys, could make such estimates seriously underestimate the rate of methane release from the hydrates.

       I don't want to bet the future of the biosphere on models of hydrate dissociation which could easily be wrong due to the highly fractured nature of hydrate deposits, often full of chimneys from past release of methane. 

       My conviction is that if we surround the hydrate deposits with warmer water, the deposits will find a way to dissociate, via complicated mechanisms including convection and release of pressure build up of associated free methane gas reservoirs. Undersea landslides are a distinct possibility, especially after substantial methane release has weakened the deposits. So, the landslide phenomenon could be an accelerating process.

       The methane gun hypothesis of mass extinctions requires a trigger mechanism, to set off the hydrates- generally a rapid rise in CO2 is postulated. 

       The fact that our modern triggering event is so much more rapid than past triggering events makes me more alarmed rather than less alarmed. The rate that Lee Kump observed for PETM hydrate dissociation might be characteristic of that event given a much slower triggering event, less severe positive feedback effects, and the methane hydrate geographical distribution at the time.

       Regarding geographical distribution- the location of the East Siberian Arctic Shelf, located as it is under the most rapidly warming region on the planet, is particularly worrisome. Another worrisome thing is the current imbalance in ice distribution with most of the ice located in Antarctica. It seems possible that we could have a full blown methane catastrophe occurring in the north, while Antarctica remains relatively intact. This would slow water rise, which in the past has helped stabilize the hydrates due to a rise in hydrostatic pressure by increased water levels.

       There are times in life when alarm is appropriate, and this is one of those times, I believe.

43172. wili at 23:37 PM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       "undersea avalanches"

       Why shouldn't these be one of the mechanisms by which methane may be suddenly released from the ocean floor. IIRC, the sea bed in the ESAS is not perfectly flat. There are deep 'canyons' where such sudden events may take place. Since the permafrost has been warming gradually over much of the Holocene, and much more rapidly lately, its structure is doubtless less solid than it would otherwise be.

        

       We have seen warmed ice start to deform this way in the GIS recently.

        

       http://www.youtube.com/watch?v=qkpFNteryX8&list=UUtZdUYUZr493AUh_EInBYxQ&feature=player_detailpage

        

       And, of course, such weakened ice would also be more susceptible to seismic shocks.

        

       In any case, there do seem to be potential 'pathways' to consider. The proper thing is to analyze the relative likelihood of each, rather than just sweeping the whole thing under the rug.

43173. MA Rodger at 23:19 PM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       Barry Woods @61.

       (-snip-)?

       Moderator Response:

       [DB] Apologies, but responses to Repetitive & Sloganeering snipped comments must also be snipped.  Barry's comment added nothing to this discussion and was necessarily treated accordingly.

43174. Glenn Tamblyn at 19:24 PM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Leland @16

       The PETM offers an interesting reference point for just how fast methane release might happen. It isn't clear what all the sources of CO2 released during the PETM were - subsea avalanches exposing methane clathrates, Antarctic permafrost, rupturing of Natural Gas deposits near Brazil are all plausible. But we do know something about the rate that CO2 levels changed.

       Lee Kump and his colleagues were able to use a core taken from near Svarlbad to give us an estimate of how fast CO2 levels were rising during the PETM. The rate was 10 times slower than today.

       Even if we assumed that all the observed CO2 rise back then originated 100% as Methane that was oxidised to CO2 it is still only 10% of current emissions of CO2. This suggests that there is an upper limit to how fast Methane will outgas today at less than 10% or so of current CO2 emissions. Particularly since no one is suggesting such dramatic triggers as undersea avalanches as part of the mix today.

       That isn't to say that the long term total emissions of Methane may not be very substantial. Just that there is a speed limit on the rate.

43175. Barry Woods at 19:07 PM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

         (-snip-)

       Moderator Response:

       [DB] Repetitive & sloganeering snipped.

43176. TonyW at 18:58 PM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       Good, useful article. Thanks.One point. How would the graph showing what might happen to a nearly instantaneous pulse of methane change if there was a gradual but significant increase in methane release? Is that more likely?I note that CH4 concentration in the atmosphere is increasing at the moment, following a few years of level concentration. Although methane may be 25 times as powerful as CO2 over 100 years, I understand that it may be as much as 100 times as powerful over a few years. Given that methane concentrations are increasing and, therefore, the degradation rate is not even keeping up with the rate of new releases, never mind exceeding it, isn't the more powerful factor of 100 a more realistic one to use? I'm not sure which factor is used in your estimate of ~0.5 W/m2.
43177. John Mason at 16:55 PM on 3 August 2013
       East Antarctica Ice-Sheet more vulnerable to melting than we thought: new research
       

       Agnostic,

       I agree with you that nothing drastic is likely to happen to the EAIS for the time being, with sea-level rise coming from the other sources you cite.

       However, I think we need to take a good hard look at the Pliocene, because we have driven one parameter straight into that era in a matter of a few centuries. How our current climate evolves in response to having a Pliocene atmosphere imposed upon it remains to be seen, but we need to be aware of what is possible....

43178. Leland Palmer at 16:22 PM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Yes, but Chris, methane catastrophes have arguably happened before, during the End Permian, the End Triassic, a couple of events in the Jurassic, and the End Paleocene (aka the PETM). Certainly, there have been a series of mass extinctions, with similar signatures in the carbon isotope ratios- a massive carbon isotope excursion best explained by the entry of several trillion tons of C12 enriched hydrate methane into the atmosphere. Or, one could postulate much, much larger amounts of CO2- except that the math does not quite work out.

       So, it's not just a theoretical possibility, is it?

       Whatever the source of methane, from decaying permafrost or methane hydrates, it was arguably sufficient to end several geological eras, right? 

       Tell me again why I have to meet your criteria before I become alarmed?

       Shouldn't we err on the side of caution, when we're talking about the fate of the biosphere?

       Isn't climate change in general, and warming in the Arctic in particular, occuring much, much more rapidly than predicted? 

       The hydroxyl radical oxidation mechanism which oxidizes methane into CO2 is also impacted by large releases of methane. Isaksen and his collaborators claim the following:

       Strong atmospheric chemistry feedback to climate warming
       from Arctic methane emissions

       It is shown that if global methane emissions were to increase by factors of 2.5 and 5.2 above current emissions, the indirect contributions to RF would be about 250% and 400%, respectively, of the RF that can be attributed to directly emitted methane alone. Assuming several hypothetical scenarios of CH4 release associated with permafrost thaw, shallow marine hydrate degassing, and submarine landslides, we find a strong positive feedback on RF through atmospheric chemistry. In particular, the impact of CH4 is enhanced through increase of its lifetime, and of atmospheric abundances of ozone, stratospheric water vapor, and CO2
       as a result of atmospheric chemical processes

       It's my alarm, Chris.

       I can't be alarmed without your permission?

        

43179. Robert Marston at 13:00 PM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       The issue I have with this article is that it paints scientists who have found evidence of a potential rapid methane release as a near equivalent to climate change deniers.

       In addition, the article clearly sides with scientists who have a very conservative view on the issue of methane release. So conservative, in fact, that all science indicating a potential for anything other than a very slow release is painted in a light so as to be considered false.

       Though PETM ocean floor heating, slope collapse and methane hydrate release theory as a mechanism for final rapid atmospheric heat increase and coordinate anoxic ocean state are just that, numerous scientific papers support evidence for such events. Wadhams and Shakova are just a few of the scientists who have issued concerns for such events in a contemporary ocean and land system due to human caused warming. Hansen, for example, has mentioned risk of methane release, both from hydrates and from land material, as a reason for keeping human CO2 levels low. So I must ask the question? Is Hansen being irresponsible?

       Further, this particular post seems to fail to take into account contemporary research showing high risk of a substantial contribution from Arctic carbon stores in the form of both methane and CO2 on the order of 43 to 135 gigatons CO2e by 2100. The study, conducted by a number of scientists for the UN is available here:

       http://www.unep.org/newscentre/default.aspx?DocumentID=2698&ArticleID=9338

       Were these scientists being irresponsible by indicating methane as a potent amplifying feedback from now to 2100 and even moreso through 2200?

       Now this particular study does not specifically indicate a potential yearly release on the order of 1-50 gigatons methane, as Shakova warns is possible. But it does indicate methane as an amplifying feedback of significant magnitude on a time scale that includes a more rapid response than that seen in the Eemian or during the most recent interglacial. It also, contrary to what Archer has stated in earlier articles, shows that emissions lower than this level are significant.

       I suppose what I find most concerning is the fact that Skeptical Science seems to have hitched itself to the, albeit professional, opinion of a few scientists who are very conservative on the issue of methane release without attempting to identify probabilities for a catastrophic release or exploring a middle ground, available in a number of reports, in which release is an important addition to CO2 forcing. The science, on this issue, includes all the scientists -- Shakova, Wadhams, Hansen, White, and others showing evidence of potential catastrophic release, others whose models indicate a more modest release, and Schmidt, Archer and others who seemingly believe that methane is almost a non-issue when it comes to climate change.

       To quote NASA scientist and CARVE researcher Charles Miller:

       "Permafrost soils are warming even faster than Arctic air temperatures - as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years," Miller said. "As heat from Earth's surface penetrates into permafrost, it threatens to mobilize these organic carbon reservoirs and release them into the atmosphere as carbon dioxide and methane, upsetting the Arctic's carbon balance and greatly exacerbating global warming."

       Is Charles Miller the alarmist equivalent of a climate change denier or are his points worth considering? I'd, therefore, compell Skeptical Science to widen its scope in coverage on the issue of methane. The breadth of science indicates instances of Arctic emissions happening now, not at catastrophic levels, but at levels indicative of concern. A valid theory supported by top scientists shows potentials for catastrophic releases of hydrates during major ocean warming events. More moderate research indicates a likelihood of significant but not catastrophic releases from now to 2100. Since neither Archer nor Schmidt can provide compelling evidence as to why their theory of 'slow release' should dominate, since they rely on a static rather than dynamic view of Arctic systems (Eemian and Holocene corrollaries), and since they seem to exclude other Earth Systems Sensitivity factors, it would seem that their views require much stronger evidence to be reassuring and that we should still consider Wadhams, Hansen and Shakhova as providing a valid warning worthy of policy consideration.

       Finally, if Schmidt and Archer are correct, then we lose nothing except a little extra effort and gaining more certainty and resiliency by acting. But if Wadhams, Shakhova and Hansen are correct, then in failing to act and gain greater understanding of potential risks, we lose a great deal.

       ....

43180. christopherwrightau at 11:15 AM on 3 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       Yep I've just finished this MOOC and it was a great course that I can thoroughly recommend. Well structured and presented and the constants testing was actually very good re knowledge application and retention. The intro to climate science was excellent for my social science sensibilities and it was also a lot of fun.

       Running again in September - so well worth doing.

43181. Riduna at 10:20 AM on 3 August 2013
       East Antarctica Ice-Sheet more vulnerable to melting than we thought: new research
       

       It is certainly possible and may be likely for the polar ice sheets to disappear, causing sea level rise (SLR) of 22 +/- 10 metres over coming millennia. Of more immediate concern is what can be expected to occur over the course of this century. The Letter from C.P. Cook et al (2013) implies that what occurred in the Pliocene is a reasonable indicator to what may happen in the immediate future. That seems questionable, as is the suggestion that some 50% of future SLR could come from ice mass loss from the East Antarctic Ice Sheet.

       SLR by 2100 is more likely to come from ice mass loss from West Antarctica (WAIS) where warm ocean currents are already melting ice at glacier mouths and attacking areas of the WAIS resting on the seabed. Atmospheric warming does not appear to contribute to ice mass loss from either the EAIS or WAIS, other than the “Peninsula”.

       This is not the case in the Arctic where loss of ice from the Greenland Ice Sheet (GIS) and Canadian Islands is caused by rising atmospheric temperature and a warming Arctic ocean. The latter is caused by penetration of warmer sea currents and loss of albedo causing increased exposure to sunlight. Further, loss of land based ice is more likely to accelerate due to Arctic amplification contributed to by methane emissions and evidenced by temperature rise at over twice the global average.

       By contrast atmospheric temperature amplification is not evident in the Antarctic which is insulated by relatively stable circumpolar winds, persistent sea-ice coverage and the loss of tropospheric ozone. All have the effect of maintaining the coldest atmospheric temperatures in the world. Warmer bottom currents from the tropics do reach the EA coast and there is evidence that these enable increased ice loss from some EAIS glaciers. However, the EAIS is entirely land based and, unlike the WAIS which is a marine ice sheet, relatively impervious to warm ocean currents.

       Both the WAIS and EAIS are loosing ice mass but the latter is doing so at a much slower rate. For these reasons it is argued that SLR to 2100 is most likely to come from the GIS with exposure to Arctic amplification and WAIS which is vulnerable and exposed to warm ocean currents. EAIS seems unnlikely to be a major contributor this century.

       Finally, is it legitimate to compare conditions during the Pliocene, which took hundreds of millennia to evolve, with present conditions which have taken just a few decades to evolve thanks to human intervention. Do present EAIS conditions equate to those which prevailed in the Pliocene?  

43182. Tom Curtis at 09:56 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       For what its worth, the Bray and von Storch survey show 83.51% of climate scientists to be convinced that most of "recent or near future climate change was, or will be, a result of anthropogenic causes", showing the concensus that GW is dangerous is almost as great as that it is anthropogenic. 

43183. Tom Curtis at 09:52 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       MA Rodger @58, the tweet clearly indicates that 97% of climate scientists agree that gobal warming is real, that it is man made, and that it is dangerous.  That each proposition is true seperately does not make it true that 97% of climate scientists agree with each proposition.  It certainly does not make it true that Cook et al 2013 show them to have believed it.  In fact, Cook et al showed endorsement in the literature, in papers stating an opinion, not being restricted to climate scientists, of the idea that global warming was real and man made.

       Consequently it would not have been out of order for John Cook to have issued a correction on any of those inaccuracies in the tweet.  In particular, it would have been quite appropriate to issue a correction saying that the papers endorsed the concept that climate change was real and man made, but that even though it is dangerous, the study did not examine the endorsement of that view.  Ergo Terranova has a point, and is not quibbling.

       I am not convinced, however, that it was compulsory on Cook or any of his coauthors to issue a correction.  If it was, surely it was compulsory to issue the correction on every point of inaccuracy, yet Terranova only seems vexed by the term "dangerous".  Further, if it was compulsory to issue a correction on Obama's tweet, then surely it is compulsory to issue a correction for every misrepresentation of the study - which is absurd.  There are not enough hours in the day.

       So, if not compulsory, does it not then enter the realm of a judgement call as to whether the inaccuracies were sufficiently misleading require correction.  Claiming the 97% of scientists believe the changes to be beneficial would have a far greater demand on correction than Obama's tweet, for other surveys have established that .  Bray and von Storch's survey shows that 78.92% of climate scientists are convinced that climat change "... poses a very serious and dangerous threat to humanity", with only 1.162% "not at all convinced".  (There is, IMO, a problem with the wording of their survey question that will bias the response low.)  So, correcting terrranova's hypothetical alternative would be correcting a radical mistatement of the facts.  In contrast, correcting Obama's tweet would be correcting inaccuracies in details (though potentially significant details).

       So, yes it would have been nice of Cook corrected those details when acknowledging the tweet.  But not compulsory, and not dishonest to find better things to do with his time.

43184. Lyndal at 09:51 AM on 3 August 2013
       Where SkS-Material gets used - Coursera's Climate Literacy Course
       

       I have done two Coursera subjects and found both to be excellent. Adjusting to the slight differences between the ways the subjects are set up was difficult at first, but the same happens between subjects in real life University studies.

43185. Chris Colose at 09:29 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Phil,

       Yes, CO2 is a product of methane oxidation (along with water vapor, which ends up having a non-negligible climate forcing in the stratosphere). 

       For fairly small perturbations, the "extra CO2" after oxidation isn't really important because there's so little of it.  There's a lot more CO2 in the atmosphere than methane.  So even if you turn methane into an extra ppm of CO2, that's not even a years worth of fossil fuel burning.  For much larger methane releases, however (hundreds to thousands of gigatons), that can add on significantly to the long term radiative forcing, even after oxidizing to CO2.  They key here is the different lifetimes of the two gases, which isn't adequately captured in existing metrics to compare different gases (like GWP).  

       The fate of a big methane injection after it oxidizes comes up in some deep-time discussions, like Snowball Earth.  By the way, for slow releases, you'd sustain higher steady-state methane concentrations during the timeframe that the release is occurring. So a slow release is still an issue.   But it's unclear to me that methane has ever been a "huge" player in climate change on Earth, at least since the planet was filled with lots of oxygen in its atmosphere (I use the word "huge" in a bigger-picture context than the still significant radiative forcings that we're talking about for contemporary global warming, e.g., for the evolution of climate over the last 60 million years, or the deglaciation of a Snowball Earth). For understanding the evolution of global climate, CO2 is much more first order.

        

43186. Tom Curtis at 09:21 AM on 3 August 2013
       2013 SkS Weekly News Roundup #29B
       

       Andy @59, the analogies are poorly designed for your purpose.  When I buy milk for my children, nobody calls that a subsidy because it is just part of my parental responsibility.   In contrast, if the government were to buy milk for my children (at school, for example), there would be no question that that would be a subsidy.  Consequently the entire force of your first analogy depends on a context in which talk of subsidy is simply inappropriate, and has no bearing on the issue at hand.

       With the renewable energy cooperative, the question arises as to the purpose for which the cooperative was established.  If it is to generate energy for sale as a source of income, then there is no question that the below market cost energy is subsidized.  More properly, it means taking profits in the form of cheaper energy rather than in cash payments; and if the result is a different distribution of receipts, it means the cheap energy is subsidizing some members of the cooperative at the expense of the others.

       More commonly, however, renewable energy cooperatives are founded for the primary purpose of providing the members with cheap renewable energy.  In that case it is not a subsidy, but only because the cooperative is fulfilling the purpose for which it was formed, and for which its members paid.

       In either case your analogy is inaccurate.  In the first because it is genuinely a subsidy.  In the second because the constitutional arrangements make specific talk of a subsidy inaccurate.

       As I am sure we will all agree that the Saudi Government was not formed for the purpose of providing cheap oil to Saudi citizens, neither of the analogies shed any light on the issue.

43187. JasonB at 09:17 AM on 3 August 2013
       2013 SkS Weekly News Roundup #29B
       

       Andy, I agree with scaddenp, and these aren't even close to being as tricky as some countries get when trying to avoid the label.

       We also had a dairy cow when I was a kid and, just like any subsidised consumption, we certainly drank a lot more milk than we would have otherwise.

       If a child (citizen) puts milk in the cart and takes it to the checkout, and the father (government) whips out his wallet and pays for the milk, then that is clearly the normal case when people think of the word "subsidy". But the net effect is the same if the father is a farmer who foregoes the income he would have received from selling that milk and gives the milk to the child directly. Milk becomes an artifically cheap commodity, and is over-consumed relative to what its level of consumption would have been had the milk been sold and the money then used to buy whatever was desired at market rates.

       Anyway, the WTO document scaddenp previously linked to clearly states:

       Secondly, the government may provide goods or services at no cost or below market price, such as university education, public transport or food stamps. Such transfers also involve expenses for the government, with the difference being that beneficiaries receive in-kind contributions as opposed to funds they can freely dispose of.

       as one of the three categories of subsidies and it also says that the WTO definition of subsidy includes:

       (ii) foregone revenues that are otherwise due

       To me, this would clearly include Saudi oil. And, has been noted multiple times already, the Saudi government itself considers this to be a subsidy.

       I can think of other examples that are similar and nobody seems to have problems calling them subsidies. In Australia we have subsidised medicine, subsidised health care, subsidised education, and subsidised housing for the poor. In each case the question is simply whether the cost to the end user is below market rates, not how much it cost nor which country it originated in.

       Consider a drug on the PBS (which Wikipedia calls a program "that provides subsidised prescription drugs to residents of Australia") for example; it's considered "subsidised" if I can buy it at the standard rate of $36.10 but the normal market price was higher than that. (If it was lower, it wouldn't be on the PBS — not all drugs are.) It doesn't matter what the actual cost of production of that drug is (which, in general, will be substantially lower, as evidenced by the massive price drop when patent protection expires and competitors start producing it), and it doesn't matter what country that drug was produced in (so if the pharmaceutical company happened to be Australian, then, just like the Saudi oil, we'd be buying our own drugs at below-market rates, and it would still be a subsidy).

       I don't know why Saudi oil being subsidised should be a controversial claim. If BHPB and Rio Tinto were forced to sell iron ore to Australians for $23.50/tonne rather than the going market rate, wouldn't that be a subsidy? (BTW, it's funny how weird that idea sounds, and what an uproar it would provoke about "Sovereign risk" if the government were to try to impose a rule guaranteeing Australian citizens unlimited consumption of iron ore at extraction costs! I suspect the WTO would also take an interest on the effect it would have on the competitiveness of the Australian steel industry.)

43188. Tom Curtis at 09:10 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       deweaver @9, the Nature article explicitly cites independent literature to justify the claim of the potentialy large methane release.  It takes that claim from elsewhere and examines the potential economic impacts of such a release.  Given that, the lack of the technical discussion you are looking for is irrelevant.  Science builds on science.  If some other scientist has established a point to your satisfaction, it is not necessary to reestablish that point in any paper you publish seeking to use those results.  Consequently your claim that this is "advocacy science" is unwarranted, and reads like a simple slur intended encourage dismissal without thought.

       Please note that I say this despite being convinced by the evidence Chris Colose adduces that such a release is very unlikely, and also evidence from a David Archer article on Real Climate.  Science does not work be expecting all scientists to be convinced by what convinces you. 

43189. Tom Curtis at 08:57 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Phil @11, the methane (CH4) does oxidize to form a CO2 molecule and and two H2O molecules, the later condensing out of the atmosphere.  The CO2 has a significantly less powerful greenhouse effect per molecule than does CH4.  Therefore the result of the oxidation is to greatly decrease the greenhouse impact of the methane release.  And, yes, this is taken into account in modeling of the effecs of a methane release on climate.

43190. Phil at 08:15 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Excuse the ignorance, but its often stated that methane has a comparatively short residency in the atmosphere, and so I've always assumed that the majority oxidises to CO2. Is this correct ? If not, what is the stable form of carbon that methane decomposes to.

       On the contrary, if so, is the extra CO2 generated by the any methane "plume" (of whatever size/duration) generally taken into account when modelling such scenarios ?

43191. scaddenp at 07:24 AM on 3 August 2013
       2013 SkS Weekly News Roundup #29B
       

       Andy. His family benefit from cheap milk but they would also benefit from him selling the milk at market prices. As son of a dairy farmer, I can tell you that there is no way we would have enjoyed inch-thick whipped cream on scones etc if we were making rational economic decision. Ditto the cooperative. 

       I would say both case represent consumption subsidies. Consumption would be lower if price was rational.

43192. MA Rodger at 06:17 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       Terranova @55.
       You appear to be offering the argument here that any who disagree with you are "quibbling" and therefore wrong.
       You evidently here are not able to find fault with AGW being described as being "real" but have a problem with AGW being described as being "dangerous." Now that is quite a bizarre position to defend.
       Indeed, can AGW be anything other than "dangerous" if it has the power to be "the primary cause of recent global warming"? While some may consider that climatology and climatologists should not decide what is dangerous or otherwise, the reaction of many climatologists to inaction in the political sphere suggests that many climatologists are not of that view.  AGW certainly could not be considered "beneficial" as you suggest denialists may term it because the "climate policy" for which a "scientific consensus is an essential element to gain public support" is entirely understood to be a policy to reduce the impacts of AGW, not to boost them.
       BarackObama's tweet makes no mention directly of Cook et al 2013 but called on readers to "read more," to read that "Rising concentrations of carbon dioxide, the main greenhouse gas, hit 400 parts per million in the atmosphere last week, the highest in perhaps 3 million years. Governments have agreed to work out, by the end of 2015, a deal to slow climate change that a U.N. panel of experts says will cause more floods, droughts and rising sea levels." That all sounds a bit dangerous to me. Then again you may find such statements controversial and unfounded although I'm not sure I could accept such a view.
       And your inability to present an adjective to describe AGW that you would be comfortable with strongly suggests to me that in truth you are actually uncomfortable with AGW existing at all. And given the now established consensus, you are perhaps able to work out for yourself what such an opinion would result in the holder being. Or FWIW perhaps not.

43193. Andy Skuce at 06:02 AM on 3 August 2013
       2013 SkS Weekly News Roundup #29B
       

       The discussion on what constitutes a subsidy is or is not seems unnecessarily heated to me. At the risk of throwing fuel on the fire, consider the following:

       if a dairy farmer provides milk directly to his family, rather tha buying it in a shop, is he or she subsidizing consumption?

       Imagine a renewable energy co-operative. If the co-op sells electricity to its members at less than the grid market price (or the feed-in tarriff) is it subsidizing its members' consumption?

43194. wili at 05:45 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       Good points, deweaver. Also not mentioned was the topography of the subsea ocean bed. There are many deep canyons, the walls of which could have methane stores that are quite close to the 'surface' that may degas violently at any moment, thereby destabilizeing the entire area, leading to more degassing.

       
       Also missing was any mention of the vast pools of highly presssurized free methane that lay beneath the permafost and hydrates, just needing a pathway to erupt explosively into the water above and thence into the atmosphere.

        

       Finally, how about the fact that well trained scientists with years of experience, such as Shakhova and Semiletov, have seen with their own eyes unprecedented levels of methane bursting into the atmosphere, burtst more than a k across.

        

       post script:

        

       Methane Hydrates - Extended Interview Extracts With Natalia Shakhova

       https://www.youtube.com/watch?v=kx1Jxk6kjbQ

       This is the last thing Shakhova says in the video:

       "strictly speaking, we do not like what we see there. Absolutely do not like."

        

       (pps. If dor can quote evidence that anyone is "wishful" for this calamity to happen, (s)he should link to evidence or stfu.)

        

43195. Terranova at 05:34 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       Michael Sweet at 56

       I agree with you that politicians can make a judgment to term AGW dangerous based on other sources. But, the Tweet, whether intentional or not, makes it appear that it was the result of the Cook study.  That is inaccurate and was repeated in print and in electronic media all over the world and never addressed by Cook or anyone else at SkS. It would be a simple thing to address through this forum if nothing else.  

       So, we agree that the study neither said, nor implied, the dangerous part.  That was purposely or mistakenly added by the person responsible for the Tweet. The implication is that it came from the Cook study. Based on the number of articles generated about this subject, I am not the only one to think so.

       In your opinion is this an important issue or not?  Politicians aren't responsible for accuracy, but scientists are.  

       And, FWIW, I am not a denier and don't read Spencer's blog.  

43196. michael sweet at 04:28 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       Terranova,

       The scientific consensus is that AGW is happening and caused by humans.  It is a policy decision to determine if that is dangerous or not.  Obama gets to make whatever policy choices he wants to.  Since Obama has other sources of information, it is completely within reason for him to determine he thinks AGW is dangerous.  Politicians make these types of judgements all the time. 

       Why should scientists be responsible for what politicians say when the denier scientists lie all the time?  The denier politicians are even worse. 

       Have you gone to Spencers blog and asked him to correct his testimony in congress where he said he was part of the 97% when all his papers were part of the 3%?

       I am sick of deniers who say scientists must be perfect while the deniers are allowed to repeat the same old lies for decades.

43197. Terranova at 04:09 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       MA Rodger at 54

       You are quibbling.  Let's stick to the point. I've already suggested that the tweet not use any adjective.  The study was about the consensus in scientific papers that stated a position on AGW.  The published paper did not make any inference to any effects caused by AGW (positive, negative or neutral).  

       However, the Obama tweet did add the adjective which was inaccurate.  In the article I referenced to you, Mr. Cook could have addressed that.  (Maybe he did and the writer did not print it.  I've been misquoted before).  Mr. Cook did gleefully accept the praise that his work generated, and rightfully so.  

       The tweet was repeated all over the internet and in print.  That becomes one of those "sticky" ideas that Mr. Cook referred to in his 1JULY13 post.  Not once have I seen any attempt to correct it.  

       Imagine a scenario where the folks over at WUWT had added the adjective beneficial.  I am certain, and you know it too, that it would have been addressed on this blog and over Twitter regardless of the limitiations that you think a tweet has.

43198. MA Rodger at 03:39 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       Terranova @53.
       You tell us "This is not about silliness, but about accuracy." I find that difficult to accept as your insistence on accuracy is very selective. You complain that one thing is 'not accurate' and should be urgently corrected while other things that are also inaccurate need no correction, indeed you happily repeat a mistake, because you do not object to the error thus made. You are surely trying to have your cake and eat it.

       You are happy to accept an inference that "scientists" equals "peer-reviewed papers on climate change 1991-2011 whose abstract expressed a position on AGW"  thus providing the 97% result that you assert is "accurate" even though this introduces an obvious error.
       But you take exception to the use of the adjective "dangerous" within the same tweet because in your opinion that is not accurate reflection of the findings of Cook et al 2013, a paper that is not in fact mentioned within the tweet.

       @50 I suggested that a tweet is not a medium for incisive accuracy, a proposition you appear to disagree as you ignored that suggestion. Yet perhaps we can work round this ignorance of your. Do you disagree that "dangerous" can be inferred from the references used by that tweet? If so, perhaps you could suggest an alternative adjective that you would be more comfortable with?

43199. deweaver at 03:39 AM on 3 August 2013
       Toward Improved Discussions of Methane & Climate
       

       What I have failed to see in these discussions that could add a lot of insight are the following:

       1- A phase diagram for methane hydrates ( methane partial pressure -- fugacity, temperature, water chemical activity, CH4/H20 ratios in the hydrate). This is well known information from the oil/gas industry -- plugging pipelines and equipment with methane hydrates is a real problem for this industry that they solved in the 30's with a full understanding of both the thermodynamics and kinetics.

       2- Heat transfer calculations using well know math, at least for petrochemical engineers. It would be easy to calculate how fast it could melt the permafrost how deep.

       3- Very little discussion of the amount of methane in shallow permafrost and distinctions between recent biogenerated gases in thawed organic materials being anaerobically decomposed and historical gas in the permafrost.

       4- No real discussion of the microbiological response of the aquatic system. If methane seeps out of sediments in 50 meter deep water, it is reasonably soluble in the water phase and one would expect bacteria to oxidize it to CO₂ and water using O₂, NO₂, NO₃, S, etc. as the electron acceptor. Are there reports of huge hypoxic zones? If we are getting massive emissions from a large area, that massive area would be anaerobic and a dead zone before any methane gets into the atmosphere. People may be thinking of a little pot hole where methane can bubble up through a meter of water without being fully adsorbed into the water column, but deeper columns of water provide more (a calculable) ability to dissolve into the water column (a standard mass transfer problem). This is what happened to the huge amount of methane produced by the BP blowout in the Gulf and other methane seeps around the world.

       5- No discussion of the minimum substrate concentration (Smin) of methane oxidizing bacteria (the minimum concentration of methane) to support the growth of methane oxidizing bacteria in soils or in water. If you are above that Smin, bacteria can grow exponentially and reduce that concentration to Smin. We are hypothesizing a factor of 10 increase in the atmospheric concentration and that may cross the Smin level and soil bacteria will increase and dramatically speed up the removal kinetics.

       Considering the above, it appears that this Nature article was really “advocacy science” and not a real study of the issue. It is this type of “advocacy science” that is destroying the credibility of solid science in the publics mind. This type of advocacy has been common in “environmental science” for decades and effectively use against powerless opponents, like aquaculture in the US, but in this case opponents are not powerless and the amount of money at stake is significant on a world scale. The loss of credibility for science will be significant and very detrimental.

43200. Terranova at 00:29 AM on 3 August 2013
       An accurately informed public is necessary for climate policy
       

       MA Rodger @ 51

       Thanks for your guidance, but I read the paper when it first came out.  In the conclusion it states: "Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW."  

       I fully realize it is referring to the percentage of published papers taking a position on the cause of global warming, or to quote Dikran Marsupial "there is a broad consensus amongst scientists working on climate-related science that the majority of climate change is anthropogenic."

       In this article Mr. Cook had ample opporunity to clarify that the paper wasn't referring to "dangerous" AGW.  

       This is not about silliness, but about accuracy. 

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