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Comments 1 to 50:

  1. Why we need to talk about the scientific consensus on climate change

    There is only one way to curtail CO2 levels and that is to stop burning fossil fuels. We all know that. The problem is that the oil and coal companies have massive amounts of money to make sure they can continue their activities. Facts and science are not the issue, its the money that supports the program of misinformation, fully backed by the media and ploiticians of the big polluting countries. We need to move on without them as they are not going to change.

  2. 2014 SkS Weekly News Roundup #47B


    Thank you for the clarification.  It is easy to confuse what is claimed with other claims.

    On the other hand, many times the damages from a small increase in summer heat are greatly disproportionate to the measured increase in temperature.  Frequently if the temeprature was 20% lower, compared to the mean, the damage from drought and heat would be greatly less.  Similarly, the last nine inches of flooding from hurricane Sandy in New York caused disproportionate damage.  That flooding was 100% due to AGW since it was sea level rise.  When combined with the uncertainty with how much of the heat is caused by AGW it is very difficult to determine how much of the damage was from AGW, even when it is most of the damage.

  3. President Obama's climate leadership faces the Keystone XL challenge

    A recent peer-reviewed article argued that, because of basic economics, the extra supply of oil on KXL will lower world prices by $3 per barrel. US domestic prices are, to a large degree, controlled by world prices so, other things being equal, US retail gasoline prices should eventually fall a bit if KXL is OK'd.

    I happen to think that this amount ($3/bbl) is too high (my arguments in an SkS post,here), but it is in the right direction. However, the oil market is very complicated and unpredictable and, although you can make predictions of the consequences of a single variable on the basis of everything else being equal, in oil markets everything else never is.

    In any case, concerns about future small changes in the price of gasoline have everything to to do with US politics and not that much relevance to sound environmental policy. I'm against KXL for the same reason that Canadian governments and oil companies are in favour of it: because it will promote production from the oil sands.

  4. 2014 SkS Weekly News Roundup #47B

    michael sweet @8, when you say Hansen showed "extremely hot summers were 98% caused by AGW", you need to be careful clariffy what is meant.  What is meant is that an extremely hot summer has a very low probability of occuring without anthropogenic forcings.  The statement could be interpreted as saying that anthropogenic forcings caused 98% of the heat or 98% of the temperature difference from the mean.  In both cases that interpretation would make the claim false.  There are problems in determining the exact temperature contributions of anthropogenic forcings to a particular hot summer (or heat wave), but an intuitive approach is to simply take the zonal land temperature increase as being the contribution of anthropogenic forcings, on which basis the anthropogenic contribution generally resolves down to 20% or less of the difference from the mean.  That is, without anthropogenic factors, what are experienced as extremely hot summers would have been very hot summers or at least hot summers (and ignoring butterfly effect complications).  The small relative contribution of anthropogenic forcings, however, takes the actual temperatures into ranges very rarely experienced without anthropogenic factors.

    (I am aware that you know this, but not all readers or this thread may, so it is worth clariffying.)  

  5. Google It - Clean Energy is Good for the Economy

    States with lower carbon emissions tend to have higher median incomes.

    That may be because higher tech energy strategies create a lot of good jobs.  It may be because wealthier states can afford to invest in the future more.  And it may be external factors that cause both, such as urbanization.  Realistically, it is probably a mix of the three.  But, the fact is, states that are better for the climate are also doing better economically.

  6. 2014 SkS Weekly News Roundup #47B

    Continuing the dice analogy what do we think when a 7 or an 8 comes up?

    Hansen showed several years ago that etremely hot summers were 98% casued by AGW.  Hotter summers than that (+ 4-5  sigma) have such a low chance of occuring that they are almost certainly caused by AGW.  This analysis does not address single hot days or weeks. 

    There is still the possibility, however small, that it could have occured without AGW. 

  7. 2014 SkS Weekly News Roundup #47B

    @ 5 and 6

    As Firgoose rightly points out, the nature of the beast is inherently non-deterministic. Let's examine this a bit deeper by putting some numbers into the dice analogy...

    In an honest die, the chance of rolling any of the six numbers (1-6) is exactly 1 in 6, or about 16.7%. Consider what happens if a pair of dice are subtly loaded in favour of the 6, such that the numbers 1-5 now each only have a 16% chance of turning up. The chance of rolling a 6 is now 1-in-5, or 20%, and hence the chance of throwing a pair of sixes has increased from 1-in-36 to 1-in-25.

    In a hundred throws of an honest pair of dice, one would expect (on average) that there would be just under 3 (or 2.77777.... to be exact) instances of a double 6 (i.e. an extreme event). With the loaded dice, this anticipated average number rises to 4 per hundred throws.

    How do you even begin to say which 3 were "legitimate" and which one could, with certainty, be attributed to the changed conditions? It is only the persistence of average results outwith the expected range which raises the eyebrow.

  8. It's not happening

    59F tomorrow for Buffalo.  15F above the daily average.   Should they now think that temperatures have risen >10 times faster than IPCC thinks?  Fact is, winter is coming, and it gets cold and snows a lot in Buffalo in the winter almost every year.  Sometimes it gets warm again.

    Ironically, though, the large amounts of lake effect snow have been linked to the warming of the lake, resulting in more evaporation, convective lift and, therefore, snow than previously seen.  It interacted with a large actic air mass, of the sort we've been seeing that last few years.  That pattern has also been attributed to global warming, though the jury is still out.

  9. One Planet Only Forever at 15:51 PM on 24 November 2014
    2014 SkS Weekly Digest #47

    I am looking forward to Alexandre Lacerda's upcoming SkS item “Drought and Deforestation in Brazil”

    The need to be able to reasonably predict things like El Nino/La Nina and resulting regional rainfall is highlighted by the current drought in Sao Paulo.

    Even if El Nino could be more reliably predicted the potential rains in Sao Paulo would appear to be difficult to reliably forecast. The presentation of El Nino impacts summarized by NOAA here indicates that rainier conditions would be expected in southern Brazil but potentially not as far north as Sao Paulo.

    An added challenge of the rapid climate change due to rapidly increased impacts like atmospheric CO2 appears to be that rapid short-term changes of climate patterns make it even more difficult to establish reliable short-term forecast models (models to regionally predict things like generally expected rainfall 3 to 6 months in advance) because what has happened in the past in the short-term is less likely to be what will happen in the future.

    Sao Paulo appears to be at the mercy of whatever will come in the next few months. And a few years ago Tofino on 'reliably rainy' Vancouver Island had its reservoir almost run dry without getting warning several months in advance that it was likely to happen.

  10. CO2 limits will harm the economy

    Check out how carbon emissions correlate to median income.

  11. 2014 SkS Weekly News Roundup #47B

    @5, localis: It's somewhat like loaded dice that have been fixed to increase the number of sixes. You can know that the dice are loaded and, given enough trials, you can determine an accurate percentage of sixes above the level that chance would produce. You cannot, however, say what exact balance of natural and unnatural factors influenced any particular six, nor can you predict whether the next roll will produce a six or not.

    I have great respect for the scientific method but there has to be a time when reputations cease to be so important

    It's not about reputation, it's about being scientific. The inability to definitively differentiate the random-roll factors from the dice-loading factors would still be the case with dice so loaded that they gave sixes 99.9% of the time. So any reticence to declare certainty about any given six is quite justified. On the other hand, with sufficient data there should equally be reticence to state that there won't be more sixes on average. And the longer the sequences of rolls that you record, the more certainly you can declare the influence of the loading factor for the sequence. Similarly you can make predictions for future sequences, the longer the better.

    To me this is food for the deniers to thrive on.

    I quite agree but unfortunately everything seems to be food for the deniers. I can't imagine how they'll do it yet but I fully expect them to spin the end of the hiatus as some kind of "proof" and a victory for their anti-science. ;o)

  12. 2014 SkS Weekly Digest #47

    The "Tropical Pacific Ocean moves closer to El Niño" link is not working.  It links to a page with the address "" which gives a 404 error.

    Moderator Response:

    [JH] Link fixed. Thanks for bringing this glitch to our attention.

  13. President Obama's climate leadership faces the Keystone XL challenge

    OPOF...  The other bit I think Russ is missing is the fact that you can't just consider domestic economics relative to supply and demand. The issue is, refiners are going to sell their products where ever they can get the highest price, and any product they sell in the US market is going to be below world price for those products. 

    That is going to have the effect of pushing domestic prices higher.

    Ironically, the Forbes article I linked is written by Tim Worstall, who is a UKIP supporter, and by no means a liberal.

  14. Why we need to talk about the scientific consensus on climate change

    Glad to see my horrible typing may serve a larger purpose!  That way I don't have to learn how to correct it.

  15. One Planet Only Forever at 11:32 AM on 23 November 2014
    President Obama's climate leadership faces the Keystone XL challenge

    Russ R.,

    Specifically to your point regarding gas prices in the US.

    In addition to the many articles referred to by Rob, here is another reference. It includes the following statements which are consistent with the sales pitches the Alberta Government and other promoters of the oil sands currently continue to proclaim, XL will increase the price they can get for Oil Sand Bitumen which is a key part of the mid-West US refining system.

    "TransCanada’s 2008 Permit Application states “Existing markets for Canadian heavy crude, principally PADD II [U.S. Midwest], are currently oversupplied, resulting in price discounting for Canadian heavy crude oil. Access to the USGC [U.S. Gulf Coast] via the Keystone XL Pipeline is expected to strengthen Canadian crude oil pricing in [the Midwest] by removing this oversupply. This is expected to increase the price of heavy crude to the equivalent cost of imported crude. The resultant increase in the price of heavy crude is estimated to provide an increase in annual revenue to the Canadian producing industry in 2013 of US $2 billion to US $3.9 billion.”"

    "Independent analysis of these figures found this would increase per-gallon prices by 20 cents/gallon in the Midwest."

  16. One Planet Only Forever at 09:39 AM on 23 November 2014
    President Obama's climate leadership faces the Keystone XL challenge

    Russ R.,

    The purpose of this discussion is the justification of XL.

    There may be other reasons people may 'want' XL but XL is unjustified unless you or anyone else can substantively refute the points I provided. QED

    Moderator Response:

    [JH] The first sentence of the SkS Comments Policy reads as follows:

    The purpose of the discussion threads is to allow notification and correction of errors in the article, and to permit clarification of related points. 

    Russ R's commentary about a statement made in the OP is therefore legitimate. He/she is, however, skating on the thin ice of excessive repetition which is prohibited.   

  17. President Obama's climate leadership faces the Keystone XL challenge

    Russ... Here's a study from Cornell.

    KXL will divert Tar Sands oil now supplying Midwest refineries, so it can be sold at higher prices to the Gulf Coast and export markets. As a result, consumers in the Midwest could be paying 10 to 20 cents more per gallon for gasoline and diesel fuel. These additional costs (estimated to total $2–4 billion) will suppress other spending and will therefore cost jobs.

    That 10-20 cents a gallon completely wipes out any gains we achieve from additional jobs within about a year. [LINK]

  18. President Obama's climate leadership faces the Keystone XL challenge

    Russ @40...  May I ask, did you read any of the articles that I posted stating that KXL would likely cause gas prices to rise nationally?

  19. President Obama's climate leadership faces the Keystone XL challenge

    One Planet Only Forever,

    Your comment @41 is not in any way a response to my argument @40.

    Starting from my first comment in this thread @1, I've been solely focused on a single issue... whether or not KXL will raise gasoline prices in the US, as claimed in the original post.  

    I'm not discussing other arguments.  There are many, many cases to be made both for and against the approval of this pipeline, but at least some of those arguments may be factual.

    The claim that KXL will raise US gasoline prices is pure fiction, and I've laid out the facts refuting it.

    Moderator Response:

    [JH] You are again skating on the thin ice of excessive repetition which is prohibited by SkS Comments Policy.

  20. One Planet Only Forever at 08:20 AM on 23 November 2014
    President Obama's climate leadership faces the Keystone XL challenge

    Apologies in advance to the Moderator, but I find it difficult to resist responding to Russ R's recent elaborate presentation.

    Russ R.,

    Please substantively refute all of the following (previously pointed out points regarding this issue that your most recent comment does not address):

    • The burning of buried hydrocarbons needs to be curtailed to meet a total global cap on the resulting emissions. Only a small percentage of the buried hydrocarbons currently located and able to be extracted can be allowed to be burned.
    • It would be beneficial if a maximum amount of useable energy was obtained from the burning done within the global limit. It would be even more beneficial if the burning did not produce impacts reaching the global limit.
    • The hydrocarbons planned to be shipped through XL are among the poorest sources of useable energy for the harm done to get that useable energy. The resource is not in the top half of the most beneficial to burn so it clearly is counter-productive to burn it.

    Unless you can substantively refute all of the above (and there are more points against what XL would prolong and potentially expand that would have to be refuted), the XL pipeline is not justified. QED

  21. 2014 SkS Weekly News Roundup #47B

    Thankyou for your replies but what I have difficulty with is the obvious evidence of climate change throughout the globe especially in the Artic and good evidence of melting glaciers elsewhere but when it comes to attributing any weather event to climate change there seems a reticence to do so by many scientists. To me this is food for the deniers to thrive on. I have great respect for the scientific method but there has to be a time when reputations cease to be so important if we are to escape the science itself becoming the millstone that condemns us to failure.

  22. 2014 SkS Weekly News Roundup #47B

    localis @3 anthropogenic climates forcings are a factor in every weather event that occurs (which I believe is what you are saying).  However, just because it is sunny with a chance of showers in Brisbane today (made up example) does not mean that the probability of its being sunny with a chance of showers in Brisbane in November would have been low without anthropogenic forcings.  In fact, given conditions over the range of holocene climate conditions, that would have been a reasonably common occurence in any event.  So, while it is true that anthropogenic factors are a factor in every modern weather event, it does not mean that the probability of such weather events has been changed by anthropogenic factors.  And it is such changes in probability that we are concerned with.

    However, for some types of weather events there have been detectable increases in the probability of such events (particularly extreme warm weather, but also floods and droughts) which are potentially attributable to the influence of anthropogenic forcing.  Typically such events are similar to events that are fairly common (or would have been) in any event, but small increments in temperature, or evaporation (for droughts) or precipitation (for floods and hurricanes) have increased the intensity of the event so that very intense events are occuring more frequently.

    Further, some of the events are so intense that the probability of their occuring if their had been no anthropogenic forcing is << 1% (the 2010 Russian heat wave comes to mind; as does the proximate cause of the 2011 Brisbane floods, although the floods themselves were not unprecedented and have a magnitude with a return interval between 50 and 100 years).

    So, as I understand your point it is valid - but it is not very interesting except to note that some pseudo-sketpics contradict themselves by insisting that (a) weather is chaotic, such that "the flap of a butterflies wings can cause hurricanes", but that (b) anthropogenic factors have not influence on weather.

  23. 2014 SkS Weekly News Roundup #47B

    At what point do we accept that anthropogenic climate change is actually taking place? If we accept that it is actually occurring now (as many scientists seem to concur) then all weather events must be accepted as being influenced by that change unless it can be proved that any part of our climate system functions independently of the rest.

  24. President Obama's climate leadership faces the Keystone XL challenge

    Rob Honeycutt @25,

    I'm going to take the time to break this down into components, and provide evidence where required.  You're welcome to dispute any point, or the reasoning linking them together.

    1. The Keystone XL pipeline will not reduce the overall supply of crude oil to the USA.
      1. The pipeline's origin will be in Canada and its terminus will be in the United States.
      2. Unless the direction of flow were to be reduced, the pipeline could not possibly reduce the total US supply of crude oil.
      3. Any reduction of crude oil supply in one region of the US (i.e. the Midwest) must necessarily result in an equal increase in crude oil supply further downstream (i.e. the Gulf Coast).
    2. The pipeline will reduce the cost of transporting crude oil.
      1. Transporting crude oil by pipeline is generally cheaper than by rail, at a cost of about $5 a barrel compared with $10 to $15 a barrel.
      2. Canada is currently exporting 163k bpd of crude oil by rail because existing pipelines are already at capacity.
      3. Additional pipeline capacity will reduce the volume of crude being shipped by railcar, reducing average costs.
    3. The pipeline's crude oil payload is not "earmarked for export".
      1. The refineries in the US Gulf Coast are specialized for the processing of heavy crude oil, having invested in complex secondary conversion equipment that breaks down long-chain hydrocarbons to produce greater volumes of higher value light fractions (gasoline, kerosene and diesel) relative to lower value heavy fractions (residual fuel oil, lube oil, asphalt and pet coke).  (Background reading.  Disclosure... I previously worked at McKinsey and advised clients on matters relating to refineries, pipelines, and many other things).
      2. The US currenly imports heavy crude from Mexico (919k bpd) and Venezuela (806k bpd).
      3. The pipeline will have capacity of 830k bpd, which is less than the amount of Latin American heavy oil currently being imported.
      4. The pipeline will displace crude oil imports, but is too small to result in crude oil exports.
    4. The pipeline will not increase exports of refined products.
      1. The US Gulf Coast refineries are operating at full capacity.
      2. Given the option of procuring cheaper fuel via pipeline, refiners will substitute it for more expensive Latin American heavy crude oil, but this will only lower their costs, not increase their output of refined products.
      3. That Latin American crude oil will, in turn, find its way by tanker to refiners in other foreign markets, contributing to foreign supply and lowering foreign prices for both crude oil and refined product.
      4. Since the Keystone pipeline will in no way reduce US demand for refined products, there is no reason that more refined product would be exported, especially since foreign markets would already see increased supply and lower prices.


    If the Keystone XL pipeline will result in:

    1. No decline in US crude oil supply,
    2. A reduction in transportation costs,
    3. No increase in exports of crude oil, and 
    4. No increase in exports of refined product,

    then, the pipeline will not cause the average price of US refined products (i.e. gasoline) to rise.

    NB.  The above is not an argument that US gasoline prices will fall.  In all likelihood, the lower costs of inputs and transportation will result in higher profit margins for refiners, with no significant change in the price at the pump.  

    This phenomenon was already observed in the Midwest, as a regional glut of crude oil (caused by insufficient pipeline capacity) brought down the price of crude oil but had no impact on retail gasoline prices.  Where did all the savings go?  To the refiners.

    Read about it for yourself:  The Incidence of an Oil Glut: Who Benefits from Cheap CrudeOil in the Midwest? Borenstein & Kellogg (2014)

    Regarding Keystone XL, the authors conclude:

    "The merits of these capacity expansions—particularly the Keystone XL project—have been a matter of public debate on both environmental grounds and the extent to which it will impact U.S. gasoline prices. While this paper is silent on environmental impacts, it does imply that the impacts on gasoline prices will be extremely limited. Because expanding Midwest crude oil export capacity will have only a minimal impact on Gulf Coast and world oil prices, U.S. consumers outside the Midwest will not experience a decline in gasoline prices. As for Midwest consumers, our results imply that capacity expansions that increase the Midwest crude oil price will not increase the Midwest gasoline price. This price is already being set by gasoline refined using Gulf Coast rather than Midwest oil, despite the depressed Midwest oil price. Resolving the Midwest crude oil transportation bottleneck will not affect this situation, thereby leaving Midwest gasoline prices unaffected as well."

  25. 2014 SkS Weekly News Roundup #47B

    localis: From the SkS Climate Science Glossary:

    Extreme weather event

    An extreme weather event is an event that is rare at a particular place and time of year. Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of the observed probability density function. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense. Single extreme events cannot be simply and directly attributed to anthropogenic climate change, as there is always a finite chance the event in question might have occurred naturally. When a pattern of extreme weather persists for some time, such as a season, it may be classed as an extreme climate event, especially if it yields an average or total that is itself extreme (e.g., drought or heavy rainfall over a season).

    Definition courtesy of IPCC AR4.

  26. 2014 SkS Weekly News Roundup #47B

    Surely all weather events that are now occurring, extreme or otherwise, are linked to climate change. Weather systems are all connected so it seems nonsense to isolate a particular event and state it is or isn't connected to climate change. We argue for scientific accuracy about what is happening to the climate and classifying individual weather events as "yes or no" seems a matter of opinion rather than accurate science.

  27. Why we need to talk about the scientific consensus on climate change

    Stephen Baines @40

    "econcomically" ... a shining example of "in typo veritas". It has always struck me that those who dismiss climate models are so certain about the predictive power of economic models forcasts of financial devastation when their track record is, to put it charitably, less than robust.

  28. New study shows warm waters are melting Antarctica from below

    dorje @7.

    Further to Rob Honeycutt @8, the temperature profile of Greenland shows only static heat fluxes from below. The changes are all from above and their impact can be used to plot Greenland surface temperatures at the summit of the ice cap back into the last ice age. And this would not be possible if the flux from below were changing with time.

  29. Why we need to talk about the scientific consensus on climate change

    ubrew12.  From I remember, having lived through it as a yong person, frankelfkin is actually correct, for the most part.  The oil embargo by OPEC created a huge increase in gas proces and shortages at gas stations that led to a large recession.  Energy independence was considered a key national security and economic issue by Carter.  His stated energy policy pretty clearly asserts this.  He was also interested in controlling environmental damage, but he was mostly thinking about atmospheric and water pollution by power plants and strip mining — including effects of acid rain.  

    By the time Reagan entered the white house OPEC had adopted a far less econcomically destabilizing pricing scheme - possibly due to competition from other sources.  The issue of energy independence had stopped being a political winner, and he claimed he was interested in market solutions that did not involve government intervention.  Acid rain and ozone would be the major environmental battles of the 80s in the US.

    One thing Carter did do in his policy was have money set aside to study effects of CO2 on the climate.  

    "--The President will request almost $3 million to study the long-term effects of carbon dioxide from coal and other hydrocarbons on the atmosphere (budget)."

    It's down the list a bit though. Doesn't seem like it was the major priority, and I (having lived through it all) don't remember it being mentioned as being important in the political landscape of the time. 

  30. Why we need to talk about the scientific consensus on climate change

    franklefkin@24: you are suggesting that American conservatives don't care about energy independence.  Carter cared: hence-renewables.  Reagan didn't care: hence-no renewables.  Nope.  In American politics, energy independence from the Middle East is a major political talking point among conservatives.  That's been true since the OPEC embargo.  But, if true, why did Reagan nix research that would have led to just such an energy independence?  The result indicates that neither side cares as much about energy independence (the subsequent push for 'Globalization' underscores this point).  What then, spurred Carter's investment?  I say Global Warming.  

  31. New study shows warm waters are melting Antarctica from below

    dorje...  Do you understand that these paper are not claiming that heating from below the ice sheets has changed any time in recent history, that would explain what we attribute to changes in greenhouse gas concentrations? They are merely quantifying the effect, which has likely been unchanged over the past century.

  32. New study shows warm waters are melting Antarctica from below

    Abstract/Summary of "Heat flux variations beneath central Greenland's ice", 2013:
    At the Earth’s surface, heat fluxes from the interior1 are generally insignificant compared with those from the Sun and atmosphere2, except in areas permanently blanketed by ice. Modelling studies show that geothermal heat flux influences the internal thermal structure of ice sheets and the distribution of basal melt water3, and it should be taken into account in planning deep ice drilling campaigns and climate reconstructions4. Here we use a coupled ice–lithosphere model driven by climate and show that the oldest and thickest part of the Greenland Ice Sheet is strongly influenced by heat flow from the deep Earth. We find that the geothermal heat flux in central Greenland increases from west to east due to thinning of the lithosphere, which is only about 25–66% as thick as is typical for terrains of early Proterozoic age5. Complex interactions between geothermal heat flow and glaciation-induced thermal perturbations in the upper crust over glacial cycles lead to strong regional variations in basal ice conditions, with areas of rapid basal melting adjoining areas of extremely cold basal ice. Our findings demonstrate the role that the structure of the solid Earth plays in the dynamics of surface processes.

  33. New study shows warm waters are melting Antarctica from below

    dorje...  Neither of these papers say anything that would suggest that heat from submarine volcanoes is responsible for the warming of the past 50-100 years.

  34. New study shows warm waters are melting Antarctica from below

    Schroeder paper states:  We also observe high geothermal flux in the upper reaches of the central tributaries that are relatively close to the site of the WAIS Divide ice core (Fig. 3, location B), where unexpectedly high melt and geothermal flux have been estimated.* We estimate a minimum average geothermal flux value of about 114 mW/m2 with a notional uncertainty of about 10 mW/m2 for the Thwaites Glacier catchment with areas exceeding 200 mW/m2 (Fig. 3). These values are likely underestimates due to the low uniform geothermal flux value used in the ice sheet model (9) and the compensating effect of enhanced vertical advection of cold shallow ice in high-melt areas.

    As for Hillier and Watts--the point of course is heat, ocean warming; the source in this case of heat are submarine volcanoes, alot of them.

  35. Why we need to talk about the scientific consensus on climate change

    Russ R wants to make much of the fact that Cook et al did not assess the level of endorsement in the scientific literature (not the level of the concensus per se) about how dangerous AGW is.  He acts as if the level of consensus among climate scientists of how dangerous AGW is has never been assessed, but of course, it has been.  Specifically, In Bray and von Storch (2010), respondents were asked:

    "22. How convinced are you that climate change poses a very serious and dangerous threat tohumanity?"

    Responses were on a seven point scale, with 1 being "not at all convinced", and 7 being "very much convinced", which makes 4 "about 50/50".  In response to that question, a plurality of scientists responded that they were very much convinced that "climate change poses a very serious and dangerous threat to humanity".  In all, 78.9% of respondents are convinced that at least on balance of probabilities, "climate change poses a very serious and dangerous threat to humanity" (response of 5+).  That compares to just 9.3% who think that on balance of probabilities, "climate change [does not pose] a very serious and dangerous threat to humanity" (response of 3-).  10.8% are fifty-fifty on the topic (response of 4).

    Those who are not so sure of the threat may be reacting to the wording, which literally aserts not just a dangerous threat, but a "very serious and dangerous threat", and not just to the economy, or to people in low lying areas, or the poor, but to humanity itself.  On the other hand, I suspect many of those who consider the threat real do not consider it to be an existential threat, but only a generalized threat in which many (even a majority) of the population will not have their lives threatened.  A better defined question may well have had a more overwhelming response, but with a lower modal value.

    I am uncomfortable describing less than  90% assent as a "consensus".  Clearly, however, far more than a super majority of climate scientists consider global warming to be potentially a very serious threat; and among those who disagree, few (1.16%) would consider such an outcome to be unrealistic.  So, while Russ R wants to make it clear that Cook et al (2013) did not address the issue of how dangerous AGW was, the fact remains that there is overwelhming scientific suport for the claim that AGW is dangerous. 

  36. Why we need to talk about the scientific consensus on climate change

    Absolutely agreed.

    Moderator Response:

    [JH] Thank you.

  37. Why we need to talk about the scientific consensus on climate change

    Moderation Comment:

    Rob Honeycutt & Russ R:

    You have now entered into the Neverland of Excessive Repitition. Please cease and desist. Your future posts will be summarily deleted if they repeat what you have already posted on this thread.

  38. Why we need to talk about the scientific consensus on climate change

    I get the sense that you fail to grasp the definition of "implicit."

    1. implied though not plainly expressed.
    "comments seen as implicit criticism of the policies"
    synonyms: implied, hinted at, suggested, insinuated

  39. Why we need to talk about the scientific consensus on climate change

    And Russ...  There is nothing about "finally admitting" anything. I have said now exactly what I've been saying all along, and the exact same thing that I've been stating since the paper was published.

  40. Why we need to talk about the scientific consensus on climate change

    Russ...  This is getting almost surreal.

    Yes, 97.1% of the papers do endorse the position that humans are causing global warming. Some do so implicitly. Some do so explicitly. Some do so explicitly and also quantify.

    Likewise, 2.9% of the papers reject the position that humans are causing warming. Some do so implicitly. Some do so explicitly. Some do so explicitly and also quantify.

    The example you presented is a paper that implicitly endorses that position, and does not implicitly reject that position.

  41. Why we need to talk about the scientific consensus on climate change

    Rob Honeycutt @30,

    Thank you for finally admitting that a Level 3 rating "does not need to have a specific claim relative to >50% of warming."   That's spelled out very clearly in the paper's methodology.

    But if Level 3 papers don't need to make a specific claim that humans are causing >50% of warming (and most that I've looked at make no such claim), then how can anyone claim that 97.1% of the abstracts find that humans are causing most warming?   The paper itself doesn't even make that claim... it only states:  "Among abstracts expressing a position on AGW, 97.1% endorsed the consensus position that humans are causing global warming."

  42. Why we need to talk about the scientific consensus on climate change

    Russ... Think of the exersize as being like this:

    You have a large bowl of puzzle pieces in front of you. The puzzle pieces come from several different puzzles. Your task is to find out what percentage of them fit one specific puzzle. That puzzle is the IPCC position stating that there is a >95% likelihood that more than half of warming over the past 50 years is due to human causes.

    There are seven other smaller bowls in front of you that you can place the pieces in, ranging from clearly fit to clearly do not fit. And you have one bowl in the middle for pieces that do not fit either way.

    What you are doing is conflating bowls 2&3 with bowls 5,6&7 in order to say that you can only build the puzzle with the pieces from bowl 1. This is clearly wrong. 

    The abstract you're presenting very clearly fits the idea that humans are the primary cause of warming. We have a problem with global warming and they are presenting a study that addresses one small issue related to that problem. 

    There is another puzzle (or likely several different puzzles) that can be constructed with the pieces from the rejection bowls that suggest that humans are not primarily responsible for global warming. The pieces in bowls 2&3 are ones that do not fit those puzzles.

  43. Why we need to talk about the scientific consensus on climate change

    Russ...  Cook13 was not attempting to only locate papers that quantitatively endorse the IPCC position. We were also looking at papers that implicitly endorse, as well as explicitly endorse without quantifying.

    The abstract you posted is a category 3. An implicit endorsement. It's not an implicit rejection since it does not minimize the IPCC position. It does not need to have a specific claim relative to >50% of warming. Any paper that made a specific claim would be an explicit endorsement (cat 2), and any paper quantifying the endorsement would be a category 1, explicit with quantification.

  44. Why we need to talk about the scientific consensus on climate change

    Rob Honeycutt @26 & 27,

    I'm not disputing the rating assigned to the Bronson & Mosier (1991) abstract above.  I just don't see how the abstract as written can possibly be intepreted as a claim that humans cause most (>50%) of warming.

    "We're talking about the endorsement or rejection of the IPCC position on global warming. The paper is offering a mechanism to reduce emissions of methane due to rice cultivation. Why the heck would they be concerned about reducing methane emissions if global warming is primarily a product of natural variation?"

    That's great... it's an implicit endorsement of the IPCC's general position.  But it's not support for a specific claim that most warming is man-made.

  45. Why we need to talk about the scientific consensus on climate change

    "I'd encourage the editors of this site to do likewise whenever they reference the Obama/OFA tweet."

    Then we can also assume that you would expect every "skeptic" blog out there to make similar qualifications every single time they mention the "pause." They must acknowledge when they cherry pick RSS. They must clearly state that there is warming in all the other data sets. They must also acknowledge cherry picking of start dates to present such a claim. And with models they must also clearly acknowledge when they are choosing single year baselines when comparing models to surface temps.

    I could provide you a list a mile long where "skeptics" are vastly more egregious in their presentations of information. But, I don't need to really do that because all you have to do is go to the "Most Used Myths" section of SkS in the left side column of this webpage.

  46. Why we need to talk about the scientific consensus on climate change

    And, btw, your interpretation is clearly incorrect.

  47. Why we need to talk about the scientific consensus on climate change

    Russ @23...  (sigh)

    1) Only categories 1 and 7 quantify.

    2) Ask yourself this question: Does this paper minimise human contribution relative to the IPCC position? 

    We're talking about the endorsement or rejection of the IPCC position on global warming. The paper is offering a mechanism to reduce emissions of methane due to rice cultivation. Why the heck would they be concerned about reducing methane emissions if global warming is primarily a product of natural variation?

  48. Why we need to talk about the scientific consensus on climate change

    Andy Skuce,

    Thank you.  I hadn't previously seen your blog or that post.  I stand corrected.

    Good on you for making that distinction.  

    I'd encourage the editors of this site to do likewise whenever they reference the Obama/OFA tweet.

    Moderator Response:

    [JH] Your recommendation has been duely noted — multiple times in fact. Any future posts by you that repeat your recommendtion will be summarily dismissed. Enough already!

  49. Why we need to talk about the scientific consensus on climate change

    ubrew12 @18,


    The reason for the uptake in spending for alternative fuels at that time was due to oil embargos (and general instability of supply) from OPEC nations, not due to any concern over climate change.

  50. Why we need to talk about the scientific consensus on climate change

    Rob Honeycutt @15,

    " No one participating in the rating of abstracts did their ratings as you're stating. Nor did any of the author self-ratings get applied that way."

    Alright then.  Let's be very specific about how abstracts were rated.

    Consider the following abstract to the Level 3 rated paper Effect Of Encapsulated Calcium Carbide On Dinitrogen, Nitrous-oxide, Methane, And Carbon-dioxide Emissions From Flooded Rice, Bronson & Mosier (1991):

    "The efficiency of N use in flooded rice is usually low, chiefly due to gaseous losses. Emission of CH4, a gas implicated in global warming, can also be substantial in flooded rice. In a greenhouse study, the nitrification inhibitor encapsulated calcium carbide (a slow-release source of acetylene) was added with 75, 150, and 225 mg of 75 atom % 15N urea-N to flooded pots containing 18-day-old rice (Oryza sativa L.) plants. Urea treatments without calcium carbide were included as controls. After the application of encapsulated calcium carbide, 3.6 μg N2, 12.4 μg N2O-N, and 3.6 mg CH4 were emitted per pot in 30 days. Without calcium carbide, 3.0 mg N2, 22.8 μg N2O-N, and 39.0 mg CH4 per pot were emitted during the same period. The rate of N added had a positive effect on N2 and N2O emissions, but the effect on CH4 emissions varied with time. Carbon dioxide emissions were lower with encapsulated calcium carbide than without. The use of encapsulated calcium carbide appears effective in eliminating N2 losses, and in minimizing emissions of the “greenhouse gases” N2O and CH4 in flooded rice."

    I've bolded the only the specific references to climate change.  The authors are very clear in pointing out that N2O and CH4, which are released from rice growing, are greenhouse gases.  

    They discuss CO2, another GHG, but without any mention of its warming contribution, and they do so in the same manner as N2, which has no warming potential.

    From the above acknowledgement that CH4 and N2O are GHGs, and that rice growing releases these gases, one can conclude that some warming must be manmade.  But the paper makes no quantification of how much of the total observed warming is manmade, and therefore can't possibly be taken as an endorsement that most warming is human caused.

    So unless I'm mistaken, this abstract fits into the category of endorsing the weak position (humans cause >0%), but not endorsing the strong position (humans cause >50%).  Nor does it minimize human contribution (endorsing <50%).

    Is my interpretation correct?

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