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Comments 1 to 50 out of 54:

  1. This is an excellent summary, but overlooks our problem: Here in the US, money trumps all when key decisions are made. As long as the oil and gas companies are raking in such vast amounts of cash- and sprinkling it around to politicians and media companies- we will continue to bake.

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  2. @mike roddy

    agreed. To me this is a good statement of the obvious and we should all do our bit to lower our carbon footprint. I found a good place for me in the UK for advice and help to do our bit.

    I dispair of the USA. It was such a fantastic country when I lived there in the late '70s whilst doing my PhD at the Harvard Smithsonian Observatory. It seems however to have lost its way. Al Gore's book "The Future" is quite interesting in its analysis of the current disfunctionality of the US. For me its deeply saddening that a country I held in the highest regard seems to have become more part of the problem rather than the solution in a number of areas in particular CC


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  3. Regarding plane crashes etc.

    Really the issue is survivability. If you happen to be on a plane that does crash the probability of surviving is far less than say that of being in a train crash.

    eg. if you compare the worse case scenarios of different types of transport. Some are better than others.

    It boils down to whether imagination wins over statistics.

    If you imagine yourself in a crash, your better off in a train.
    If you check the math, it probably doesn't matter much (although I haven't checked!).

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  4. If you don't accept that the climate is changing or that we are causing it or if we are causing it, it will only be good for us then forget Climate Change.

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  5. Unfortunately there is a gap in Andrew's logic that those who wish to avoid action can shoot huge holes in.

    While I agree action should be taken one canot ignore the COSTS of taking action.  These are not insignificant.  The switch away from fossil fuels has a significant economic cost associated with it and is not a "no regrets" policy if warming turns out to not be severe.

    Although it's a complex issue confounded by how the current economics of fossil fuels are determined (for example failing to account to the true health costs even without climate change) the fact is that overbuild required for renewables is not insignificant - estimates vary from as much as 2x to 5x nameplate capacity.  And frequently such costs estimates fail to account for additional transmission costs (typically 50% or more of the real costs of grid based power).

    And before anyone quotes BZE at me you need to address their heroic assumptions about reductions in consumption AND the fact that they largely ignore the ovebuild and transmission cost question.

    For action to be logical today on the basis that the science is clear that there is a non-negligible risk of severe warming with potentially large negative consequences you have to address the issue that the costs of taking action (replacing fossil fuels as an energy source) do not outweigh the benefits should warming turn out to be less severe than feared.

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    Moderator Response:

    [DB] As Michael Sweet notes, your comment more properly belongs on the Putting an End to the Myth that Renewable Energy is too Expensive thread.  Please take this discussion there.

  6. Mark,

    I noticed that you provide exactly zero references to suppport you Gish Gallop against renewable energy.  Here is a SkS link that discusses your myths.  Gish gallopers like you never mention that natural gas plants also operate at 30-40% of capacity.  If you stick around and provide support for your assertions (in the unlikely case that you can find support), I will link more articles that show renewable energy is cheaper than fossil fuels.

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    Moderator Response:

    [DB] Thank you for modeling good thread discussion habits.

  7. Correct me if I'm wrong but the 97% figure applies only to scientists who believe that anthropogenic warming is happening,not that it will be severe.

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  8. @ BillyJoe #7:

    What is your working definition of "severe AGW"?

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  9. JH, I think SkS should start a compendium of all the definitions for "C" ("catastrophic") in the oft-used "CAGW."

    Oceans boiling away.  All life dead.  All humans dead.  Humans reduced to "caveman" status.  300 meter sea level rise.  40 Cat5 hurricanes per year.  Multiple monster tornado outbreaks annually.  And all of this should already have happened or else the theory of AGW is falsified and/or benign.

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  10. Catastrophic?  Is that what the C stands for?

    I always thought they meant Confused About Global Warming.

    [You learn something new every day.]

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  11. Mark,

    if warming turns out to not be severe.


    ...should warming turn out to be less severe than feared.

    These "possiblities" are not on the table, not even remotely.  There is absolutely zero chance that the consequences of warming will not be severe if we reach 450 ppm, and at the moment it appears virtually certain that we will not only reach but blow right past 450 ppm.  I put 575 ppm at the bare minimum where we will stop, and then only after many national economies are simply crushed by the impacts, and so stop emitting by default.

    Anyone who is saying "gee, this isn't so bad now" is kidding themselves.  Climate change takes time, a lot of time, but after you've jumped out the window it's too late to start worrying about what happens at the end of the fall.

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  12. DSL - Catastrophic? Don't forget monsters erupting from Arctic ice (along with mad scientists and frozen cavemen), cats and dogs living together in sin, and the horrors of the loss of our morning coffee

    ...the most favourable outcome is a c. 65% reduction in the number of pre-existing bioclimatically suitable localities, and at worst an almost 100% reduction, by 2080... Arabica coffee is confimed as a climate sensitive species...

    I would certainly consider that catastrophic, your opinion may vary. But don't talk to me until after my first cup!

    Personal opinion - the catastrophe for most of those in denial are the loss of the "infinite growth" and "anyone can win" scenarios that are fundamental ideological touchposts for so many (they live in their parents basement, so to speak, but they could do so so much!). They just seem to be fundamentally disturbed by the ideas of limits, the idea that unlimited expansion is not possible in a finite world. And egged on by those whose income is related to not having accounting for social carbon costs, or to avoiding regulation, etc. 

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  13. Sphaerica @11, in science very few things have "absolutely zero chance", and the chance that climate sensitivity is at the lower limit of the IPCC range and that the utility impact of temperature increase is also at the lower limit is significantly better than, for example, the chance of a single ticket winning a state lottery.  Further, in this lottery we only get to buy one ticket (reality).  So while agreeing that it is absurdly optimistic to hope that BAU will be all right, I do need to note that your claim is is an example of hyperbole.

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  14. Kr, based on comments in denialati sites, it seems the catastrophe that most fear is more taxes, or at very least paying a higher cost for energy. Costs associated with warming are apparently avoidable  - paid by somebody else.

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  15. My apologies, the first link in my previous post (under "monsters erupting from Arctic ice") should have been to this

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  16. Speaking of Things buried under polar ice, my bedtime reading right now is "Who Goes There?", the short story from John Campbell that forms the basis of various films, including the two versions of The Thing.  A serendipity of sorts, or, since DB is watching and the subject is denier's dictionary, "serenderpity."

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  17. BillyJoe @7, Cook et al 2013 (The Concensus Project paper) rates papers rather than authors, and so the 97% is not directly  translatable to "97% of scientists".  Rather, it is 97% of papers in the literature on climate change, that state a position.  As it happens, it is known from Anderegg et al that scientists "convinced by the evidence" that AGW is real publish at approximately twice the rate of those who are "not convinced by the evidence".  Allowing for that, around 94% of scientists publishing on climate change accept that AGW is real, where AGW is defined as believing that the surface of the Earth has warmed significantly over the 20th century and at least 50% of the warming since 1950 has been anthropogenic in origin.  Nothing in the paper refers to how dangerous that is, so the results cannot be directly read as indicating acceptance that AGW is dangerous.

    I should note that the 94% is dragged down by higher disagreement early in analyzed period, and that on independent evidence it is likely that that figure is greater than 95% currently.  Having said that, Bray and von Storch 2010 show that only 83.5% of climate scientists in 2008 were convinced that "most of recent or near future climate change is, or will be, mostly a result of anthropogenic causes" (Question 21).  That compares to 93.8% who are convinced that "climate change, whether natural or anthropogenic, is occuring now" (question 20).  I think the Bray and von Storch questions are poorly framed (see discussion below), and that that poor framing has dragged down the percentage of acceptance.  Accepting the Bray and von Storch figure is, however a reasonable position.

    The interesting quesiton in Bray and von Storch is question 22:


    At face value, this shows that in 2008, 78.92% of climate scientists were convinced that climate change posed a serious and dangerous threat to humanity.

    Unfortunately, the question as posed is multiply ambiguous.  If somebody says that they think there is only a 5% probability that humans are the only intelligent life in the galaxy, it would be absurd for them to say that they are a little bit convinced of that claim.  Rather, they are rather firmly convinced that it is not the case.  Following this logic, the questions posed by Bray and von Storch are missing 6 values, with the value of 1 being forced to do service for everybody who considers the claim or its contrary to be at best 50/50.  Thus on this interpretation, the "skeptics" and the unconvinced represent only 1.162% of climate scientists.  In fact most people will assume standard conventions rather than the strict logic of the question apply, and will treat a value of 4 as being 50/50 on the statement.  However, it is likely that some respondents where more logical than that, which would introduce a bias away from a high percentage as being convinced.  This bias applies also to questions 20 and 21.

    Further, the question arises as to what constitutes a threat to "humanity".  Does it have to be a threat to humanity as a whole, or only to individual members thereof?  And does it have to be a threat to survival, or only way of life?  Question 22 as posed is open to being interpretted such that only extinction threats count; or that only threats of massive population reduction count as threats to humanity under the terms of the question.  This possibility is reinforced by the conjoint qualifiers, serious and dangerous.  Because they are conjoint (ie, joined by an "and"), a person thinking the threat to humanity to be serious, but not dangerous (or dangerous, but not serious) would be required to disagree with the statement.  These possibe interpretations also introduce a bias against strong agreement with this statement.

    Finally, it is open to interpret the scale as an index of relative danger, or as a binary choice.  In the first instance, responses would be made based on the scale of how dangerous AGW was thought to be, with 1 representing "not dangerous or beneficial" and 7 representing "extinction level threat".  On the later (probably more correct) interpretation, somebody who thought the threat of AGW was very real but not dangerous could potentially answer 1, depending on how convinced they were of their position.  The former interpretation would bias the results towards the middle, while the later interpretation would bias results towards the lower end of the scale.

    It is important to understand that what is relevant here is not your particular interpretation, or Bray and von Storch's particular interpretation, but the range and frequency of differing interpretations by respondents.

    Overall, this ambiguity suggests to me that the Bray and von Storch results consistently under represent the agreement with the concensus.  They do, however, show that the level of agreement of climate scientists that AGW is dangerous is only slightly less than the level of agreement that GW is AGW.  Further, they show that that level of agreement is at least around 80%, and IMO is likely higher.  Thus it is certainly a supermajority (<66%) of climate scientists that agree that AGW is a serious and dangerous threat to humanity, but it may not be strong enough agreement to be considered a concensus position.  The weaker statement that AGW is a significant threat, however is likely to command a concensus among climate scientists.  I do not know how you scale "severe" to comment on that.

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  18. Mark Harrigan #5, the video addressed costs by saying we are going to have to move to renewables whether we like it or not.

    I wonder how the people whining about making changes now would behave if they were born 100 years into the future instead and had to deal with society running up against real fossil fuel supply limitations. We can't risk paying $6/gallon in the US tomorrow -- no, way Jose -- but our great grand kids should not mind $60/gallon if the whiners around the world today have their way with policy?

    scaddenp #14, yup.

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  19. "97% of scientists agree that global warming may be severe."

    This is not an actionable scientific statement...any more than a statement that, "97% of scientists agree that an asteroid could destroy human civilization" is an actionable scientific statement.

    Obviously, 97% of scientists agree that an asteroid could destroy human civilization. (And that outcome would be pretty "severe.") But it means nothing from public policy standpoint.


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  20. Mark Bahner @19, the two statements are obviously not comparable.  That is because while it is true (I suppose) that 97% of scientists think that an asteroid impact could be "serious and dangerous" they do not think it likely in any given short time frame.  According to NASA, "... an impact by an asteroid larger than 1-2 kilometers could degrade the global climate, leading to widespread crop failure and loss of life. Such global environmental catastrophes, which place the entire population of the Earth at risk, are estimated to take place several times per million years on average."  Taking "several" to mean 10 (it is likely to be less), that means in any given century there is a 0.1% of such a cataclysmic impact (and a 1% chance in the next thousand years).  So, that means that around 97% of relevant scientists believe there is a 0.1% chance of so devestating an impact in the next century.

    In contrast, at least 80% of relevant scientists (see my post @17) think it very likely that AGW will cause devastation on a similar scale to the asteroid impact within the next 100 years.

    Further, your claim that the statements are "not actionable" represent a ridiculous rhetorical ploy.  The statements by themselves with no further context do not inform us as to which are, and which are not reasonable policies, ie, "are not actionable".  But the statements are not made shorn of context.  There is a massive context of further facts summarized by the IPCC on which we can draw, and which can certainly guide policy.  

    Given that your point depends on:

    1) comparing two disparate probabilities as though they were approximately equal (despite knowing better); and

    2) deliberately ignoring a host of further available information,

    it strikes me as nothing beyond vacuous rhetoric. 

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  21. Actually, the statements would be comparable if we were currently staring down a large asteroid.  97% of scientists might say, "Yup, that sucker is big enough to destroy civilization and there's a high likelihood it's on target to hit us."  

    You would also likely see 3% of scientists still saying the asteroid is clearly there, but it's too small to do significant damage and might not hit us anyway.

    Then you'd have people on the internet running websites called WUWTA (What's up with that asteroid) running articles of people saying thing like:

    "Asteroids are likely made of spongy material." and...

    "Asteroid impacts are a natural event."  and...

    "The asteroid is clearly going the other direction." and...

    "Asteroids are missing other planets, so this one will likely miss us."  and...

    "Asteroid projection are done with computer models and thus can't accurately estimate the true track."  and...


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  22. Rob@21,

    There would be no incentive for the  "impact denial" movement, unless the asteroid was made of gold, or some rare earth mineral, or some other substance proclaimed to be a miracle homeopathic remedy that can extend your life to 1000s y.

    Your WUWTA would've been just secondary hub of "impact denial" associating those who believe in the miraculous properties of the asteroid.

    The primary hub would exist of those who, even if knowing the signifficance of potential damage to the civilisation, they have claimed the exclusive rights to the asteroid, and make money by trading their claims on the stock market. Those primary "impact denialists" would rather make sure the asteroid hits the Earth, because that would increase the value of their wealth on the stock market.

    I'm sorry if this quasi-sober & entertaining vision goes off topic.

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  23. In contrast, at least 80% of relevant scientists (see my post @17) think it very likely that AGW will cause devastation on a similar scale to the asteroid impact within the next 100 years.

    Please name 10-20 of these "scientists", because the statement that AGW could cause "devastation on a similar scale to the impact of an asteroid (1-2 km in size) in the next 100 years" is patently ridiculous. Here are some projected effects of a 1 km asteroid hitting earth:

    1) Energy release of 46,000 megatons of TNT. (Comparable to the explosive power of all the nuclear weapons on earth exploding at once.)

    2) A crater 14 km in diameter. (In contrast, Meteor Crater in Arizona is only 1 km in diameter.)

    3) An 18-meter tsunami at a distance of 1000 km from an ocean landing site (and 8 meters at 3000 km from the landing site).

    And the effects are much more devastating for a 2-km asteroid. Estimates for that size asteroid are that more than 1 billion people would be killed.

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  24. Mark Bahner @23,

    First, this point is an obvious attempt at distraction from the fundamental disanalogy within your example - ie, the estimated probability of the event within the next 100 years.


    The difference between the devastation of an asteroid impact, and that of global warming is that the former is localized while the later is global.  Thus, quoting the peak energy release is not a relevant comparison.

    Consider a 1.6 km iron asteroid hitting Earth at 30km/s and an angle of 45 degrees.

    It will release 1.84 million megatonnes energy.  Never the less, at 1000 km, the most severe immediate effect will be to shatter glass.  Its ejecta is likely to also cause a short lived episode of very cold years.  Of course, within 600 km radius, devastation is almost complete.

    In addition to providing almost total devastation to 0.2% of the Earth's surface, the devastation of a 1.6 km impactor would be very limited in time, with direct effects being over within days and indirect effects excluding damage.

    An ocean impact is in many ways worse, with the tsunami at 1000 km being 11 to 22 meters, and an impact midway between the US and Europe causing a tsunami of about 3 to 6 meters on both shores.  It does so, however, with 14 hours notice, so the actual loss of life should be minimal (4 hours at 1000 km).  Further, the effect would only ever by felt in one ocean basin (indeed part of any single ocean basin) 

    It is ambiguous whether you are saying 1 billion would be killed by a 2 km impactor, or a 1 km impactor, but the extreme localization of the events make such estimates very dubious.  A 1.6 km impact in Germany, for example, would kill almost everybody in Germany, and a significant population near Germany, but residents of Spain, Britain and Greece would be effectively untouched.  The death toll would be 100 to 200 million.  In contrast, an impact in the Antarctic would have a death toll only in the 100s.  The 1 billion is clearly the upper end of a large probability range.

    For comparison, the upper end of the probability range for AGW is currently about 6.25 billion.  The lower end of the probability range is around 500,000 (approximately 3 times the estimate of the current annual death toll from global warming).  The reason for the high potential death toll from global warming is that, unlike the very localized effects of a 1 km impactor, global warming is ubiquitious.

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  25. Mark Bahner, the fundamental flaw in your logic is that there are no known >1-2km asteroids on a collision course with Earth, and it is highly unlikely such objects will be discovered over the next century or so, albeit the risk is non-zero. Therefore, despite >97% planetary scientists agreeing that such impacts are likely on geological timescale (indeed, near-certain), there is precious little that is "actionable" about an impact threat from an undiscovered object. You can't divert/destroy an object you have not found! We could launch some kind of defence system "just in case", but it would likely not need used.In contrast, >97% of climate scientists understand the hazard of global warming caused by very real, very present, and (contrary to what Tony Abbott thinks) very visible greenhouse gases, emitted by human activity. They are there, demonstrably casing the warming now. Reducing our emissions of those gases is very "actionable" indeed. We can actively mitigate this threat immediately - ie actively significantly lower the probability of significant damage, unlike with your undiscovered asteroid.
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  26. This whole video is flawed because it a form of Pascal’s Wager. No one really knows the odds one way or another, so people do not see either choice as valid. Inaction is a typical response.

    @1 I don’t think big oil is buying votes or controlling congress. Democrats line up on environmental issues, and Republicans don’t (they line up behind corporations). No amount of money is going to change any of that, so no one is buying anything or any control.

    I think most people do not tend to believe the dire AGW forecasts or predictions for a couple of reasons:

    1) (-snip-).

    2) (-snip-).

    3) (-snip-).

    (-snip-). Reduce fossil fuels because it is a good thing to do. There is a finite amount of it, so we’re going to run out some day. But right now, it is cheap, cost effective, and very high energy density. Until something comes a long that is better, then things will not change. People will not change, or allow laws to change, if it costs a lot more or reduces capability. The majority rules, and the majority is cheap.


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    Moderator Response:

    [DB] Sloganeering snipped.

  27. Stealth, perhaps you might like to look at the "Its too hard" argument. Frankly, your comments come across someone who is trying to rationalize doing nothing rather engaging with science. The evidence is that climate has a sensitivity between 2 and 4.5. Even at low end, mitigation is cheaper than adaptation. You think studies are making rediculous claims, so how about you cite a study you think is flawed, and give us some evidence as to why it is flawed (in an appropriate thread).

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  28. StealthAircraftSoftwareModeler,

    some thoughts I have on your comments in @26.

    You took exception to @1 mike roddy's comment about oil companies influence. You say you don't think big oil is buying votes or controlling congress. I would just say it doesn't take "control" to accomplish the goal of preventing action and appropriate leadersip for addressing climate change: it takes "monkey wrenches". This is the point  the comment @1 was making I think, and in my opinion this is what is happening. 

    And yes, exact prediction is impossible. The magnitude of the negative impacts of climate change can only be approximated.  But I'm convinced that these approximations are valid. To compare the best estimate of impacts from a concensus of the science will yeild an approximation of reality that is likely to resemble the actual reality. The majority climate science contrarians influencing public opinion, as far as I can tell, are not interested inhonestly bracketing the problems a warming planet might cause us, but instead have the goal downplaying the science to the point that those that most of the public is misinformed.

    And I'm not sure your example about the accuracy of weather predictions and climate models is a very good one. A better analogy might be a groundwater flow model where a basin scale model can answer the gross flux issues with good accuravy but modeling localized pumping interference effects is much more difficult.

    What can one person do? Not much. One person flying a private airplane full of sandwiches to Berlin in 1948 would not have helped.  One coal plant scrubbing emissions would not make dent in the acid rain problem.  Too bad all those Berliners were starved, and the acid rain problem has continued to worsen over the decades - wait that didn't happen.

    It takes good leadership, looking at the problems seriously, honest players without ulterior motives, and buy in from the public. Don't know a better way to put it than that an honest person could find much fault with news stories leaning towards "AGW will bring problems", but also find the "it's no problem"-bunch of contrarians to be happy to point the public in the oppisite direction of reality.


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  29. For evidence of extent to which FF companies fund US politicians, this link is pretty interesting.

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  30. As an adjunct to John Cook's excellent polling of Climate Science papers since 1990, and Climate Scientists themselves, perhaps someone should just go out there and ask anyone over Age 50: has the climate changed or not?

    The deniers have convinced themselves, and an astonishing fraction of the population, that the ENTIRE Climate Science profession is being paid off by Mr. Gore himself, to lie about an aspect of nature they can access themselves by going out the front door and looking UP.  So why not enlist THEM, themselves, as the 'climate scientists'.  Have you, if you're over 50, seen a change in climate?  It could be useful.

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  31. unbrew12: I don't know about that method for increasing the number of people that accept the reality of human impact on climate. I'm a bit over 50 and I can't say I've seen a change in climate.  From what I understand, we are only now starting to see the impacts in some of the indicators. John Q Public living near the coast can't tell that sea level has risin since he was a kid. And even if he imagined he could see a difference he doesn't have to believe there is a large human caused influence.  You'd be better off surveying, say, those responsible for water supply planning that are familiar with historic reservoir fill data and runoff curves and such in areas that are starting to be impacted. There are lots of other examples that are probably valid as well. But I think the main thing is to somehow get the population to realize the reality that scientists are much more trustworthy source of information than the other purveyors of opinion such as thinktanks whose purpose is to market doubt.  It may (I hope not though) be the case that future generations will be able to say they've seen the climate change..."my dad used to have a farm but the droughts got more frequent and..." We don't want to get to that point.  As a population we need to accept the results of the work done by experts, have the basic literacy to comprehend the graphs, etc, and not be fooled by false skeptics.  That is what it will take.


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  32. ubrew12 @30, human senses are not good at recording "temperature".  Rather, they record heat flow, which can change with age.  Further, human memory is not crash hot either, and is unikely to register a change of 0.7 C in temperature between youth and current conditions.  I know that early each summer, temperatures feel hot which late in the summer I would consider cool because I am better adapted to the heat.  Given that, the idea that I could reliably register the difference in temperature now compared to that 45 years ago (when I was seven) is not plausible, even if I was in the same city (which I am not).

    Having said that, my mother accepts climate change implicitly because she has noticed that the Jacaranda's in Brisbane now bloom a month earlier than they did when she was studying teaching here.  Specific anecdotal evidence like that, or like the date cherries bloom in Japan, or ice forms on lakes in Canada can form significant evidence of a changing climate - and have been used in scientific studies for just that purpose.

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  33. (-snip-)

    Point 1 - There IS a hole in the logic.  I am not saying it cannot be filled.  But it IS necessary to address the issue of what the are costs of mitigation (via renewables, reduction in consumption and efficiiency).  It needs to be shown that these are less than the costs of the damge that climate change will produce

    Point 2 - To have some say (as they did) that the chance of warming turning out to be mild (i.e. at the low end of the climate sensitivity arguments) is zero is just as egregious and scientifically ignorant as the deniers who refuse to acknowledge that it might be much worse.  The fact is we do not know.  There is non- negligible risk climate sensitivity is high and the damage function similarly high - but it also may turn out not to be so/  (-snip-).

    Point 3 - (-snip-)

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    Moderator Response:

    [JH] You are skating on the thin ice of excessive repetition and sloganeering, both of which are prohibited by the site's Comment Policy. Please cease and desist, or face the consequences.

    [DB] Off-topic snipped.  The next off-topic comment will be deleted in its entirety.

  34. mark,

    I directly addressed your comments.  You claim (without any support) that renewables are more expensive.  I referred you to another thread where that was discussed and the conclusion was that renewables are not more expensive.  Because you did not read the link you do not realize why you are wrong.  Recently I linked to a peer reviewed study where they calculated the cost of using renewables compared to fossil fuels in the New York area.  They built three times as much nameplate wind as you point out above (natural gas also only produces 30% of nameplate, does that bother you?).  The renewables were cheaper than the fossil fuels.  I cannot find the link because it was not on the correct thread (it is on one of the weekly review threads, why don't you find it since you like to post on unrelated threads).  Since you have provided no links to support your wild claims and do not bother to read links I give you, I do not need to provide links here.  Peer reviewed data shows that you are incorrect in your claim that renewables are more expensive.  Post on the correct thread if you want more information.

    You also claim incorrectly that it might not be too bad.  There is a thread for that argument also.  If you do not follow the organization plan the arguments become too repetitive, because everyone thinks they have a new argument.  Your argument is not new and has already been addressed on the appropriate thread.

    Your point three is obviously wrong.  It is rude to come to a site and tell the moderators how to run their site when we have developed rules over several years.  If you posted to the correct thread, and cited your claims, I will provide the information you claim you want.  Read the background information you have already been linked to.

    Your conclusion was refuted on the link I gave you.  Read the links.  It is not my responsibility to spoon feed you everything you want.  You are required to do your homework and read the background information.

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  35. Tom Curtis,

    You're right. Here is what Andrew Dessler said, "Future warming may be severe."

    Here's a comparable statement, "An asteroid may hit the earth in the next century. The effects may be severe."

    Neither statement is scientifically actionable, because there is no further explanation for either the phrase "may be" or "severe" in either statement.

    Here's information that Andrew Dessler could have provided to assess the need for action:

    1) What 97% of scientists think is the most likely global average surface temperature increase, in the absence of action, and with action.

    2) What 97% of scientists think is the most likely global average sea level rise from 2013 to 2100, in the absence of action, and with action.

    3) What 97% of scientists think the most likely worldwide average life expectancy at birth will be for someone in 2100 without action and with action.

    4) What 97% of scientists think the most likely worldwide average per-capita GDP will be for 2100, with and without action.

    5) What 97% of scientists think the most likely number of malaria deaths will be, with and without action.

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  36. Mark harrigan - you argument would be better if you could cite some credible science supporting a climate sensitivity of less than 2. Hoping it will be low without also doing any kind of risk assessment for it being greater than 3 doesnt sound like sensible strategy to me. Words like "severe" or "mild" arent really that useful. Better is to look at what the projected climatic effects will be for a sensitivity of 2 and compare those impacts with costs of mitigation now.

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  37. Mark Bahner @35, you are angling to suggest that Andrew Dessler does not adress the issue as to which has the greatest net cost, switching to renewable energy or maintaining business as usual.  That, however, is not the case.  He adresses the issue very specifically from 4:38 in the video.  He says:

    "There are several reasons to think that switching to renewable energy, even if climate change turns out to not be a very serious problem, is not a terribly bad action.  There are co-benefits, such as cleaner air and political benefits of not using fossil fuels.  In addition, its a reversible decision.  If we choose not to burn coal now, we can always burn it later.  And finally, it is inevitable.  We're going to run out of fossil fuel, and we're going to have to make the switch; and in general the earlier you start making these changes, the cheaper they are - so starting now has that advantage.

    It is also worth pointing out that climate change is, at a very fundamental level, irreversible.  Every cubic kilometer of ice we loose, every centimeter of sea level rise that occurs - those are not going to be reversed on any timescale that we care about.  Those are irreversible changes so far as I'm concerned.  And irreversibility means that you have to be very certain of the costs and benefits before you take an irreversible action.

    And so when you put all this together, it seems very clear to me that the worse error is not taking action on climate change, and having it turn out to be severe.  And I think that if you want to argue that we should listen to the 3% of dissident scientists, then you have to make the argument that that is not the case - that switching to renewable energy is the worse mistake.  I think that that's an extremely difficult argument to make."

    I would add to that that:

    1)  BAU will result in a change in global means surface temperature as great as the difference between the last glacial maximum and the preindustrial average; and the assumption that such a large change can be made without major disruption of agriculture is fanciful;

    2)  Global warming has a high probability of completely or partially destroying major ecosystems including all arctic and subarctic ecosystems, the Amazonian rainforest, and the Great Barrier Reef (which is an almost certain casualty of ocean acidification alone, let alone the additional impacts of global warming) and the idea that humanity can swan along unharmed amidst such wide spread ecological catastrophes is again, fanciful; and

    3)  The most detailed economic analyses of the issue, as represented in IPCC WG 2 and 3 show the economic cost of BAU to be greater than that of taking action to prevent climate change, even though they make the absurd assumption that no matter how great the impact of climate change, it will never slow economic growth.

    Thus, Dessler adresses the issue you raise and your complaint appears to boil down to that he does not do so in the same detail as WG 2 & 3 within the scope of a six minute video.  

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  38. Mark Harrigan @33, your point (1) is clearly addressed by Dessler in his video, as shown in the transcript @37.  The "hole in the logic" is, it turns out, simply a matter of your not paying attention to what was said.

    0 0

    No, I'm saying that Andrew Dessler's statement that "97% of scientists think global warming may be severe" means precisely nothing without further defining:

    1) What "may" means...a 50 percent probability? 10 percent? 1 percent? 0.1 percent?

    2) What "severe" much global temperature rise, how much sea level rise, what will it do to global GDP, what will it do to life expectancy, and so on.


    0 0
    Moderator Response:

    [PW} Mark, you have been given incisive and complete answers to this, on this forum and in Dessler's video. It's clear you do not like the answers and are now on *extremely* thin ice, wrt to sloganeering. Further sloganeering ~will~ be removed.

  40. Rob Honeycutt @ 21.  Great response, there's always the "outliers" who are facile in their characterizations of "what is happenning."

    "Reality", however, is not dependent on whether or not a vote is taken. 

    I hold out a consistent hope that the existential "Reality" of the potential end of "everything of value" on this Planet, (which I call Gaia just because some of y'all love the term muchly)   ":<)

    will cause a paradigm shift in how we relate to one another.


    How does one put a "cost" on an activity which may -stop- further evolution on the planet? And then price a gallon of gasoline to offset it?

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  41. “Mark, you have been given incisive and complete answers to this, on this forum and in Dessler's video.”

    That is demonstrably false. I will give you $200 if you will identify the point in Dessler’s 6-minute video in which he states:

    1) What percentage probability is associated with the word “may” (i.e., “a 50 percent probability” or “a 10 percent probability” or “a 1 percent probability”, and

    2) What he means by “severe” (i.e., “global surface temperature change greater than ‘x’,” “sea level rise greater than ‘y’, ”reduction in life expectancy greater than ‘z’, etc.)

    0 0
    Moderator Response:

    [DB] "That is demonstrably false"

    This is tiresome.  Please demonstrate where "on this forum" (not just in the video) you have not been given your "incisive and complete answers".

    You will be held accountable to this.

  42. @ Scaddenup You and other seem to have misinterpreted me.  And climate sensitivity is not the topic of this thread (although clearly it is not entirely irrelevant given the nature of Andrew Dessler's argument).

    However the IPCC clearly supports a response to doubling of GHG emssions to be possibly less than 2 degrees - as indeed this site itself makes clear

    Of course it is equally likely it may be very high.  But I am not specualting either way (personally I worry it will be high as the ocean heat capacity - while enormous - is not infinite and we do not yet know enough about long term ocean circulation to be unconcerned - if the heat currently stored there does find it's way into the atmosphere in the near term that is a huge problem)

    My point, which apparently I have not made clear, is that Andrew's argument needs to be buttressed.  Because if climate sensitivity does turn out to be low (fingers crossed) and the costs of renewables do turn out to be high (a possiblity that cannot be ruled out) then taking action is NOT a no regrets policy.


    Perhaps you should read Nordhaus?  His economic analysis is quite clear that there is a point at which taking action becomes economically non-viable (i.e. costs of action are higher than the damage avoided).  The interesting debate is where that occurs (none too easy to establish but important none the less)

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    Moderator Response:

    [JH] You have made your point. It's time for you and others to move on.    

  43. @ Michael,

    With due respect what you did was make a snide attack that my comments were a "Gish Gallop" - now you use condescending language like "spoon feeding".

    Do you really think this is a constructive way to debate?

    You also misrepresent me. At no stage did I say renewables are more expensive. I stated facts. 1) that the cost of switching is not zero 2) The economics of costing energy (fossil and renewables) is complex, 3) It is necessary for renewables to have nameplate overbuild in order to gain significant penetration of the overall supply (read the AMEO report on this) and (4) that not infrequently such costings ignore the grid transmission costs (BZE being one)

    Nor did I ever claim "it might not be too bad". I simply stated that is a fact that projections of climate sensitivity include the possibility that this is low. (To be clear my personal worry is this is not the case)

    Please re-read my original post more closely.

    Also - I don't what to have a debate here about renewables costs. As the moderators rightly point out such a detailed debate is off topic (although you might like to look at this ) I was however talking about the relative costs of renewables versus the costs of damage as being relevant to Andrew's argument

    My main point was that Andrew's logic is basically that we can take action with no regrets. That is not true under a scenario where climate sensitivity turns out to be low and costs of renewables exceed our optimistic expectations.

    Instead of assuming I make "wild claims" perhaps you should open your mind to arguments and debate from someone who is saying that the arguments made by Andrew (which are generally pretty solid) need some work?

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    Moderator Response:

    [JH] You have made your point. It's time for you and others to move on.  

  44. Mark Harrigan: Lest there be any confusion, here's what the Comments Policy says about "excessive repetition." 

    Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.

    This is your second and final warning about this policy. If you post repetitive comments in the future, they will be summarily deleted.

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  45. Mark Harrigan @43, Dessler takes the conclusions of the IPCC, including those of Working Group 2 and Working Group 3 as being part of the concensus position.  Those Working Groups find that the cost of inaction excedes the cost of action with high probability.  He then gives a meta-justification for acting on the supposition that the findings of the IPCC are correct - including the findings in Working Group 2 and 3.

    Given that, your criticism is no more coherent than insisting that he needed to expound the evidence for the existence of a planetary greenhouse effect, or that CO2 absorbed IR radiation.  It is reasonable to address those issues, but doing so in no way impacts the validity of Dessler's argument, which takes as given the assessments made by the IPCC as being one of the two positions set before us (ie, the one "agreed to by the 97%").

    If you wish to adress Dessler's argument, you need to adress the reasons given for considering not acting on the information as presented by the IPCC as being the "worse outcome".  I have transcribed those reasons @37.  I believe that discussing those meta-reasons would not violate the moderator's strictures.

    Alternatively you can ignore the moderator's comments and return to your current line of argument.  Doing so, IMO, consists of just pointing out again in greater detail that in addition to the position of the "97%", there is a "3%" that disagrees.

    (Note:  I put the percentage figures in scare quotes because there is not a 97% consensus accepting central findings of the full IPCC report.  Rather, there is a 97% consensus that the Earth is warming rapidly, and that that warming is primarilly human caused, and at least an 80% agreement that that warming projected into the future with BAU is dangerous.)

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  46. Please demonstrate where "on this forum" (not just in the video) you have not been given your "incisive and complete answers".

    My questions were:

    1) What percentage probability did Andrew Dessler mean by the word "may" (e.g., <50%, <10%, <1%)?, and

    2) What measurable parameters did he mean by the word "severe" (e.g., “global surface temperature change greater than ‘x’,” “sea level rise greater than ‘y’, ”reduction in life expectancy greater than ‘z’, etc.)?

    Since not one comment has been from Andrew Dessler, or has quoted Andrew Dessler in responding to my questions, or has referred to any document from which Andrew Dessler was obviously getting his information, it's obvious that nowhere on this forum have I been given "incisive and complete answers" to my questions, since my questions were about what *Andrew Dessler meant* by the statement that 97% of scientists think that "climate change may be severe." If you'd like me to list each comment wherein I did *not* get "incisive and complete answers" to my questions, they are: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, and now 46.

    P.S. Just FYI, it's much more common in science for people who make a claim like "you have received incisive and complete answers to your questions" to point to the specific place where those alleged "incisive and complete answers" exist, rather than to ask the questioner to point to all of the places where the alleged “incisive and complete answers” do *not* exist.

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  47. Mark Bahner @46, at the very start of the video, Andrew Dessler says:

    "Should we listen to the 97% of scientists representing the mainstream view of climate science ..."

    The view of the 97% is, therefore, clearly indicated as being the "mainstream view", which is the position represented by the IPCC.  This has previously been indicated to you, and ignored by you.  You may have formed the opinion that the IPCC AR4 is neither "incisive" nor "complete" enough to answer your questions, but that view must be considered ideosyncratic, and IMO is purely tactical.  You may be prepared to say it, but it is for effect rather than to represent your beliefs.

    What the IPCC AR4 doesn't to is suit your rhetorical ploy.  It is not so stupid as to reduce "may" to a simple probability, because the probability of a particular severity of climate change depends essentially on the ongoing actions of humans as a result of explicit or implicit policies.  It does indicate probabilities given an approximate implicit policy (ie, emissions following particular scenarios).  That is, apparently, not incisive enough for you - which only shows that by incisive you mean "simplistic to the point of absurdity".  Nor, obviously, does the AR4 quantify likely deaths because these again depend on actions taken, nor not taken to avoid those deaths.  Again, to answer your questions in the framework you have chosen is to be simplistic to the point of stupidity.

    You have not wanted a complex, and nuanced response to your questions because such a response does not give you a rhetorical hostage.  That does not, however, mean that such a response has not been given.  It has!  You have simply chosen to ignore it.

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  48. Along these lines, someone just threw Jarl Kampen at me in a news comment stream.

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  49. DSL - A fascinating article, if only because the 2011 publication has zero citations to date according to Google Scholar. 

    Background - Kampen claims all of the IPCC work, all of AGW, is based on correlational studies. That claim completely ignores satellite observations, spectroscopy in general, downwelling IR, isotope ratios, stratospheric cooling, faster nighttime warming, etc.. It is therefore utter nonsense

    This does raise an issue that I've seen from time to time on 'skeptic' discussions - that without control cases there is no way to tell what the single 'experiment' we are conducting on climate might be caused by. Absurd - we face the same issues in evolution, yet that is well accepted, and in gravity, in that there is no situation without gravitational influence. 

    Every day is another experiment, another relationship of forcings, temperatures, ice mass, etc. Time provides multiple replicates, with a huge amount of data available to discern between solar, GHG, aerosol, natural cycle, and even leprechaun influences on the climate. 

    Kampen also makes the unsupported claim that AGW is not falsifiable - again, untrue, as even just simple fingerprint tests such as the vertical atmospheric profile of warming or carbon isotope ratios could, if they gave certain results, falsify anthropogenic causes. But they don't - and in fact they reject other hypotheses such as solar variation. 


    Kampen's paper is in essence a strawman argument - incorrectly describing anthropogenic global warming as correlative, as unfalsifiable, untestable, and arguing against that false depiction; when none of that is even remotely the case. 

    Promoting this kind of argument is (IMO) one of the identifying hallmarks of denial - when faced with an inability to raise solid disagreements with the science, create a strawman to argue against. It's simply a sign that the skeptic shouldn't be taken at all seriously. 

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  50. @StealthAircraftSoftwareModeler #26 I was going to suggest you read SKS post 18 October 2011 by Rob Painting "How Increasing Carbon Dioxide Heats The Ocean" which includes "This heat cannot penetrate into the ocean itself, but it does warm the cool skin layer..." and refute it with science to make your point that LWR cannot heat the ocean and get some creds, but your comment is gone or I imagined it.

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    Moderator Response:

    [DB] Hot-linked referenced post.

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