Last week, House Representative Lamar Smith held yet another masturbatory hearing to promote climate science denial. Smith is bought and paid for by Big Oil, so that is the most obvious reason he and his Republican colleagues would put on such a dog and pony show, complete with a chorus of three science deniers (Judith Curry, Roger Pielke Jr, and John Cristy). I don’t know why they invited actual and respected climate scientist Mike Mann, because all he did was ruin everything by stating facts, dispelling alt-facts, and making well timed Princess Bride references.

The hearings were called “Full Committee Hearing- Climate Science: Assumptions, Policy Implications, and the Scientific Method.”

Several others, including specialized climate science writers as well as mainstream media, have written about the hearings:

  • Dana Nuccitelli at the Guardian: Inconceivable! The latest theatrical House ‘Science’ committee hearing
  • … as is usually the case in these hearings, despite being presented with the opportunity to learn from climate experts, most of the committee members seemed more interested in expressing their beliefs, however uninformed they might be.

    At the 2:04:05 mark in the hearing video, Rep. Dan Webster (R-FL) provided a perfect example … asking witness Judith Curry what causes ice ages (Milankovich cycles, which we’ve known for nearly 100 years), so that he could make the point that natural factors caused past climate changes – a point that usually leads to a common logical fallacy (presented here in cartoon form).

    Webster proceeded to claim it was “the standard belief of most scientists” in the 1970s that the Earth was headed into an ice age.

    This has been discussed at length on this blog, see especially this guest post. It is indeed true that back in the 1960s (and a little ways into the 70s) climate scientists considered cooling as well as warming for future scenarios. As Dana points out in his post, this was partly due to the consideration of aerosols (dust) that might cause a cooling effect sufficient to push us into an ice age. But it has been understood for much longer that the most likely scenario was not cooling, but warming, if we keep putting greenhouse gasses into the atmosphere.

  • Ben Jervey at Desmog: House Science Committee Hearing Pits Three Fringe Climate Deniers Against Mainstream Climate Scientist Michael Mann
  • Ben nots that the intent of these hearings, despite the alt-reasons given by the chair, was to provide a platform for the tiny number of scientists (plus Roger) with positions that must be regarded as firmly in the science denial camp.

    Besides Dr. Mann (author of The Madhouse Effect) the other three experts will all be familiar to DeSmog readers:

  • Dr. Judith Curry, a former professor at the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, who has since resigned to focus on her private business, Climate Forecast Applications Network. Curry has admitted to receiving funding from fossil fuel companies while at Georgia Tech, and she is frequently cited and quoted by climate skeptic blogs and fossil fuel-funded politicians for her stance that the climate is “always changing.”
  • Dr. John Christy, a professor of atmospheric science and Director of the Earth System Science Center of the University of Alabama in Huntsville, and the official Alabama State Climatologist since November 2000, who routinely critiques climate modeling and has sung the praises of carbon dioxide.
  • Dr. Roger Pielke, Jr., who is not a climate scientist, but a climate science policy writer working at the University of Colorado in Boulder, and who Joe Romm at Climate Progress once called “probably the single most disputed and debunked person in the science blogosphere, especially on the subject of extreme weather and climate change.”
  • “The witness panel does not really represent the vast majority of climate scientists,” said Rep. Suzanne Bonamici, an Oregon Democrat. “Visualize 96 more climate scientists that agree with the mainstream consensus … 96 more Dr. Manns.”

  • Dan Vergano at BuzzFeed: This Famous Climate Scientist Just Endured A Washington Inquisition
  • Climate science went on trial on Wednesday at a hearing held by Congress’s notoriously grouchy science committee.//

    The witness list pitted Penn State climate scientist Michael Mann — a lightning rod for energy industry-funded attacks on scientists for two decades — against two scientists critical of their own field, former Georgia Tech scientist Judith Curry and University of Alabama satellite scientist John Christy, as well as a political scientist, Roger Pielke Jr. of the University Colorado, who has argued against links between climate change and extreme weather. These three climate skeptics had collectively testified 20 times previously at similar Congressional hearings.

    As Dan implies, the gang of three deniers, and a few others, have been before this and other panels in the US Congress again and again. Interestingly, the short list of deniers available has grown shorter over the years. There are no new ones — that 97% consensus figure works only if you include everyone. If you look only at younger scientists, it is very hard to find any deniers — so there is some attrition for the usual demographic reasons. But also, at least one denier, Heartland funded alt-Harvard scientist Willie Soon, has been taken off the list because his reputation died an ugly death from self inflicted wounds.

  • Devin Henry at The Hill: House Panel Hearing Becomes Climate Change Sparring Session
  • “The current scientific consensus on human-caused climate change is based on thousands of studies conducted by thousands of scientists all around the globe,” committee ranking member Eddie Bernice Johnson (D-Texas) said.

    … Michael Mann criticized committee Republicans for their NOAA probe, saying it “is meant to send a chilling signal to the entire research community, that if you, too, publish and speak out about the threat of human-caused climate change, we’re going to come after you.”

    Mann sparred directly with Smith, highlighting a Friday article in Science magazine that criticized Smith for speaking at a conference for climate change skeptics. Science magazine is published by the American Association for the Advancement of Science.

    “That is not known as an objective writer or magazine,” Smith said.

    Mann replied, “Well, it is ‘Science’ magazine.”

    This part, which is also discussed in the above referenced piece at the Guardian, was amazing. When Smith called the United State’s primary science journal a biased source, I could hear the sound of jaws dropping in unison across the world.

  • Rebecca Leber at Mother Jones: A Scientist Just Spent 2 Hours Debating the Biggest Global Warming Deniers in Congress
  • Michael Mann lamented that he was the only witness representing the overwhelming scientific consensus that manmade global warming poses a major threat.

    “We find ourselves at this hearing today, with three individuals who represent that tiny minority that reject this consensus or downplay its significance, and only one—myself—who is in the mainstream,” he said in his opening testimony.

    Mann blasted Republicans for “going after scientists simply because you don’t like their publications of their research—not because the science is bad, but because you find the research inconvenient to the special interests who fund your campaigns.” He added, “I would hope we could all agree that is completely inappropriate.”

  • Emily Atkin: House Republicans held an insane hearing just to attack climate science
  • The Trump administration has been nothing if not a master class in gaslighting—the art of manipulating people, often through lies, into questioning their own sanity—and its pupils on Capitol Hill have clearly been taking notes. On Wednesday, the Republicans on the House Science Committee held a three-hour hearing on the merits of climate change science, a cavalcade of falsehoods so relentless and seemingly rational that one might well need psychiatric counseling after having watched it.

    I’m going to disagree with Emily on the ordering of things. The Republicans were already very good at doing this. It may be that Trump learned from them, or it might just be that governing from the conservative agenda and real estate both involve a lot of gaslighting.

    But, she is right; this is gaslighting. EG:

    At one point, a Republican on the committee even tried to pin the label of “climate denier” on Michael Mann, a world-renowned climate scientist the Democrats had called to defend mainstream science. Georgia Congressman Barry Loudermilk asked Mann if he though it was possible, even in the slightest, that humans are not the main driver of climate change. Mann said that based on the current data, it’s not possible. Loudermilk concluded: “We could say you’re a denier of natural change.”

    Dave Levitan at Gizmodo: Today’s Congressional Hearing on Climate Change Was a Colossal Train Wreck

    It was, overall, a horrendously depressing display of scientific illiteracy, but there were some odd bits of optimism to be found. The witnesses all agreed at various points that yes, the climate is changing and that humans play a role (though they disagreed, contrary to overwhelming evidence, on the magnitude of that role), and they also agreed that the Trump administration’s proposed cuts to Earth-observing systems at NASA, NOAA, and elsewhere are a monumentally dumb idea.

    What’s more, perhaps the best point was made by one of the GOP witnesses, Roger Pielke, Jr.: “Scientific uncertainty is not going to be eliminated on this topic before we have to act.”

    In other words, not knowing everything is not a justification for doing nothing.

    One of the more disturbing moments during the hearing was when Republican representative Clay Higgins asked Mike Mann if he was a member of the Union of Concerned Scientists. At first, I was surprised to hear the answer: “No.” Then, I realized, that if you are a smart witness, often called as a witness, then other than the major professional societies, it is probably better to not be a member of anything.

    It was even more shocking when Higgins, who is clearly not the sharpest bullet in the chamber, demanded that Mann provide proof that he is not a member of the Union of Concerned Scientists. Mann indicated that he had already provided his resume, which does not say that he is a UCS member, but would be happy to send a second copy.

    Sorry, Mike, that is not proof that you are not a card carrying member of the Union of Concerned Scientists. You will need something better than that. Here, for example, is a valid Not a Member card:

    Screen Shot 2017-03-29 at 1.28.08 PM

    You’re welcome.

    I have placed the YouTube video of the entire hearing at the bottom of the post.

    Starts at about 15 minutes:

    Comments

    1. #1 Eric Lund
      April 5, 2017

      Rarely is the question asked: Is our Congressmen learning?

      In case there was any doubt about it before, I think we have a definitive answer of No regarding the ones who put R’s after their names.

    2. #2 RickA
      United States
      April 5, 2017

      The hearing provided yet another example of why name calling is bad and counter-productive.

      Not only does Dr. Mann name call – but then he lies about it during the hearing (contradicting his own written materials). As you all know – I don’t throw around the “L” word lightly – but this certainly seems like a knowing falsehood to me. Perhaps others will disagree.

      It would be so much better if people just avoided name calling in the first place. The hearing would have been much less contentious and more focused on science had the name calling and analysis thereof been left out of the hearing (in my opinion).

      Democrats and liberals seemed surprised when they learned that skeptics actually believe that the climate has changed before and that humans actually do have something to do with the current change in the climate.

      We just don’t know how much of the current change is caused by humans and how much is caused by nature (yet).

    3. #3 ...and Then There's Physics
      April 5, 2017

      We just don’t know how much of the current change is caused by humans and how much is caused by nature (yet).
      We essentially do “know”, in the sense that we can produce an estimate of how much is caused by humans and how much by nature. The estimate is a range that indicates that it is extremely unlikely that less than 50% was anthrogenic and that indicates that the best estimate is that humans are probably responsible for slightly more than all of it (in other words, nature has had a cooling influence).

    4. #4 Greg Laden
      April 5, 2017

      RickA, are you referring to Mann and others calling certain people deniers? Because if you are, that is NOT name calling. It is simply calling a denier a denier. Mann said he stands by his testimony on that. Good for him.

      Nobody is surprised when deniers provide an answer to a particular audience that suits the denier’s rhetorical needs for the moment.

      I won’t use the “l” word here.

      We know how much of the climate change we’ve witness over the last century plus is caused by various natural and human factors to a remarkable degree. Perhaps you are only familiar with the literature up to the 1970s. You should be in Congress. I noticed one of the congress critters (a Republican, of course) tried to make a point by referring to 1970s literature (and no, I’m not referring here to the smoke and mirrors of the “ice age” threat, this was a different matter).

    5. #5 Greg Laden
      April 5, 2017

      Regarding natural vs. human causes:

      “There are no known natural factors that could account for the substantial warming of the past century…. Today’s sophisticated models match up extremely well with observations of the actual climate — but only when we include the human contributions to global warming, not the natural factors alone. ”

      [SOURCE]

    6. #6 MikeN
      April 5, 2017

      >RickA, are you referring to Mann and others calling certain people deniers?

      At one point, he denied having called Curry that. Then tried to classify climate change denier vs climate science denier.

    7. #7 SteveP
      April 5, 2017

      With apologies to the late great Texas singer song writer, Phil Ochs, sung to the tune of his “Outside of a Small Circle of Friends”.

      The scientists are all convinced of human climate change.
      They’ve staked their reputations on the fact that things must change.
      Maybe we should do something and try to save the world,
      But the status quo is so much fun I’d hate to have things change
      and I’m sure it wouldn’t interest, anybody,
      outside of a small circle of friends

    8. #8 RickA
      United States
      April 5, 2017

      Greg #4:

      I respectfully disagree.

      What exactly is Dr. Curry denying?

      As you try to articulate that, I think you will see that it is mere name calling.

      She admits that the climate is changing.

      She admits that humans are causing some portion of the change.

      She admits humans could be between 50 and 99% of the change.

      Like me, I suspect she thinks it is towards the low end of that range, just as she probably thinks ECS is towards the low end of the IPCC range of 1.5c to 4.5c.

      But how can anybody who says – yes climate change is real and it is within the official IPCC range be classified as a denier.

      Pure name calling.

    9. #9 dean
      April 5, 2017

      It is amazing to see rickA try to defend curry – someone who has done fraudulent work – and present her has a torch carrier for truth, when he will turn around and accuse Mann of fraud, when none of his work has been found as such and, in fact, has been supported by numerous other researchers.

      Integrity free congenitally lying hypocrite, thy name is rickA.

    10. #10 ...and Then There's Physics
      April 5, 2017

      Rick,
      As far as I’m aware, Judith has publicly claimed that it could be mostly natural. That is clearly not consistent with the best scientific evidence available today.

    11. #11 SteveP
      Watcher Point
      April 5, 2017

      Here is what the conservative position looks like.

      Observations by an “Anthropologist” from Squeedunk

      Conservatism appears , to a remarkable extent, to be focused on legitimizing the infliction of pain on other beings for the benefit and pleasure of conservatives who, in turn, seem to believe that they have been given the right to inflict pain directly from God. When non-conservatives stick up for themselves, and incidentally cause pain to conservatives, this is considered , by conservatives, to be illegitimate behavior, because the conservative ideology only allows the purposeful infliction of pain to be administered on non-conservatives by conservatives. Everything that conservatives stand for, from gun rights ( my right to hurt an ever expanding set of human beings and animals whom I deem targetable.) abortion denial ( my right to cause incalculable pain to woman who should not be pregnant for one reason or another ), to war ( my right to murder and maim those who are not conservative if I deem them to be a potential threat to me) it is all predicated to some extent on an unspoken belief, apparently, that conservatives are “better” than others, and have a God given right to hurt them. Why do conservatives hate consumer protection? Could it be because it infringes on the conservative right to dupe the foolish, exploit the vulnerable, and basically, make profit by activities that may very well hurt or kill other human beings? The is sure what it looks like sometimes.

      The conservative ideation seems to have some inherent relationship to Christianity ( Christianity… a religion that has, as its primary symbol, a torture device with an innocent human nailed to it.) The infliction of pain, through inquisitorial behavior is a long standing Christian tradition, as the recent science monkey trial once more clearly showed.

      It is highly interesting that conservatives complain about being called deniers! Christ! They whine about freedom of speech, they whine about the undue burden of political correctness, but how dare you label them with a term that is little more than a three syllable synopsis of what they stand for in relation to legitimate concern about climate change! I guess they get upset because, if you are not a conservative, you do not have a birth right to inflict pain on others. But conservatives do. As a landlord. As a banker. As a chemical manufacturers. As a tobacco company. As an automaker.. As a manager. As president. As congressman. As Senator. Your unspoken duty as a conservative appears to be to defend the birth right to lie to, torture, maim, and kill others for your own benefit.

      That isn’t pretty is it. But that is what modern conservatism looks like today. The right to waterboard must not be abridged! The right to kill others must not be infringed! The right to hate is God given. How dare one legislate against uncivil behavior! Amen.

    12. #12 RickA
      United States
      April 5, 2017

      SteveP #11:

      I am simply calling it name calling.

      You can call that whining.

      But I am not advocating filing a defamation lawsuit, like Dr. Mann (that is whining) – I am simply calling name calling what it is – name calling.

      Greg – did you see what I just did there. You say you are just calling a denier a denier and I just said I am calling name calling name calling. Funny!

    13. #13 RickA
      April 5, 2017

      ATTP #10:

      I follow this stuff pretty closely and I don’t recall that.

      I recall her being very careful to accept the at least 50% human language from the IPCC in all her statements (I didn’t look up the exact language so if I paraphrased please forgive me).

      So I would be interested in knowing exactly what you think Dr. Curry is denying.

      Calling someone a denier is name calling – pure and simple.

    14. #14 RickA
      April 5, 2017

      dean #9:

      Can you provide a cite please for any of Dr. Curry’s fraudulent work?

      I don’t recall seeing that.

    15. #15 dean
      April 5, 2017

      “Calling someone a denier is name calling – pure and simple.”

      That is as large a bunch of crap as trying to say it is equating people with Holocaust deniers.

      If a person flatly says the message that science gives is wrong, without any reason other than the fact that “you don’t believe it”, as you do, that person is denying the science. Your faux butt hurt doesn’t mean squat.

    16. #16 RickA
      April 5, 2017

      dean #9:

      Dean says “Integrity free congenitally lying hypocrite, thy name is rickA.”

      Sticks and stones can break my bones, but words can never hurt me.

      Dean is a name caller!

      Ha ha.

    17. #17 RickA
      April 5, 2017

      dean #15 says “Your faux butt hurt doesn’t mean squat.”

      Neither does your name calling.

    18. #18 MikeN
      April 5, 2017

      Does Judy Curry have a legal case of defamation to pursue against Greg Laden and dean, since he called her work fraudulent?

    19. #19 Greg Laden
      April 5, 2017

      RickA

      “I respectfully disagree.

      What exactly is Dr. Curry denying?”

      She is firmly and repeatedly denying that climate science has a sufficient handle on the way the climate system works to be able to assert with a high degree of confidence that the warming trend we’ve seen over the last century, and the more accelerated trend we’ve seen over the last few decades, are caused by human greenhouse gas emissions and other human effects, while natural variation over those time scales has caused variation that is not linked to this upward trend.

      Exactly that.

      She refers to this as an uncertainty monster. She keeps using that term “uncertainty” but I don’t think it means what she thinks it means. It is a term of art in science, a term that requires understanding the research up to date in a field that has specifically addressed uncertainty.

    20. #20 Obstreperous Applesauce
      April 5, 2017

      RickA @~12

      “Funny” insofar as it’s peculiar that you think it’s humorous. Now that would be ‘funny’ if it weren’t so tragic.

    21. #21 dean
      April 5, 2017

      It isn’t name calling rickA. It is describing you for what you are.

    22. #22 dean
      April 5, 2017

      mikeN, I know things mathematical and statistical are beyond you, but try to pay attention.

      Curry presented an “analysis” which she claimed showed that the rise in temperature had stopped. She presented an estimate for the average rise that had an uncertainty about 4 times its value. She did this by dropping all data values pre-2001 and analyzing the remaining 9 (or 10, possibly, I forget but this was a few years ago) data values. And if that is done, mathematically the analysis gives her numbers.

      But: the problems come next. She well knew, as did the scientific and statistical community, that a sample of 10 (I’ll give her credit for a the larger case) years’ data would not have enough statistical power for any meaningful result. That didn’t keep her from presenting the work as valid.

      Second: the final two years’ of data were more than problematic: they were based on only 47 measurement stations, all in Antarctica. The previous months’ values were based on data from tens of thousands of stations: the final two points should not have been used in her (or anyone’s) analysis, as even a sophomore statistics student could tell you. The result of her analysis was driven by those two points — which, in retrospect, explains why she picked that portion of the entire data set.

      Cherry picking a portion of a large data set to match your opinion, claiming results you know you don’t have sufficient data to support, and not doing the appropriate basic diligence to ensure the quality of your data — doing all that and presenting it as valid work — case closed.

    23. #23 RickA
      United States
      April 5, 2017

      MikeN #18:

      dean – yes, Greg no.

      Personally, I would not recommend Dr. Curry sue, because dean could argue it was merely his opinion – but a lawsuit could be filed and it would be a huge hassle for dean to deal with.

      I don’t think Dr. Curry will bring such an action – because she declined to bring one against Dr. Mann for levelling the same charge.

      But yes – a suit could be brought against dean.

    24. #24 RickA
      April 5, 2017

      Greg #19:

      Interesting.

      Even the IPCC only speaks of warming post 1950 and makes no claim over the last century. So you have extended yourself past even the consensus science.

      All Dr. Curry has done is compare and contrast the warming from 1905 to 1945 with the warming from 1978 to the present.

      One supposedly occurring before much CO2 was emitted and one occurring after humans emitted most of the CO2.

    25. #25 RickA
      April 5, 2017

      dean #21.

      You appear to be in denial.

    26. #26 dean
      April 5, 2017

      Did you understand any of the comment? It’s clear rickA didn’t

      I doubt that you understand the statistics mikeN, but just in case: how would you justify what she did?

    27. #27 Greg Laden
      April 5, 2017

      RickA, I love the IPCC and all,but that report is now years old. I have incorporated all the science from the IPCC scientific basis reports (the last two) into my thinking, of course, but I also read pretty much all the climate change literature that comes out and there is quite a bit more than just what is represented in that report.

      In fact, on the date the most recent IPCC report came out it was a year out of date with respect to a couple of issues, or at least six months.

      There was a huge amount of CO2 released in the century and a half predating 1850. Since adding CO2 to the atmosphere is a long term deal, centuries long, the first 1% of the total human component, if it was 100 years ago, has had the same heating effect as the most recent 1%, times 100.

    28. #28 MikeN
      April 6, 2017

      Dean without seeing the detailed critique, I can’t comment. Sounds plausible as you describe it. However, I was really comparing to Mann v Steyn. I think all of your critique applies to the hockey stick as well:

      “Cherry picking a portion of a large data set to match your opinion, claiming results you know you don’t have sufficient data to support, and not doing the appropriate basic diligence to ensure the quality of your data — doing all that and presenting it as valid work — case closed.”

    29. #29 Marco
      April 6, 2017

      “We just don’t know how much of the current change is caused by humans and how much is caused by nature (yet).”

      “we” being “us people who have no expertise in the field whatsoever, but feel perfectly justified nonetheless to dismiss the scientific assessment”.

      “Democrats and liberals” are not surprised that you actually accept there is climate change and that humans play a role, but rather that you are willing to accept half of the science, and reject the rest.

      It really is no different than to say you accept species evolved…but humans were created.

    30. #30 BBD
      April 6, 2017

      Not this crap again.

      RickA – read harder.

      AR5 WG1 attribution statement:

      It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar to the observed warming over this period.

      What does the bit I have emboldened mean?

      Read it again.

      What is the best estimate of the human contribution to warming? >100%.

      Essential further reading. Please, do actually read it, or you will continue to be confused by JC’s errors.

    31. #31 dean
      April 6, 2017

      No mikeN, none of those issues you claim for Mann’s work are actually true. Did you miss that.

    32. #32 RickA
      United States
      April 6, 2017

      BBD #30:

      So you think Dr. Curry is in error.

      The IPCC paragraph is completely incoherent to a non statistician, and to me reads as two completely contradictory statements, back to back.

      But say I am wrong and even say that Dr. Curry is wrong and we are reading that statement totally incorrectly.

      What is the line between being wrong and being a denier.

      In my opinion calling someone a denier is name calling, where calling someone wrong is not.

      It reads differently if you say I think Dr. Curry is a denier because I think she is misunderstanding the IPCC statement of the science (to me).

      I reserve the right to wait 50 years and see what the observations show, and then determine whether the IPCC statement (incoherent as it is) is correct or not.

      But you can choose differently for yourself.

    33. #33 RickA
      April 6, 2017

      Greg #27 says “the first 1% of the total human component, if it was 100 years ago, has had the same heating effect as the most recent 1%, times 100.”

      There is something wrong with this sentence.

      If you mean that the first 1% has remained in the atmosphere for 100 years – ok.

      But the first 1% does not have the same effect as the current 1%, because of the log effect. The effect of the 20 ppm from 280 to 300 is not the same as the effect of the 20 ppm from 380 to 400. I am sure you know that, so I guess I don’t understand what you mean by the sentence I quoted.

    34. #34 Greg Laden
      April 6, 2017

      RickA, if you want to invoke the “Log Effect” then you have a huge impact of the first 20ppm added by people. This effect, interpreted as your friends at WUUWT for example, means that the CO2 added to the atmosphere today hardly matters at all, so we shouldn’t do anything about it.

    35. #35 BBD
      April 6, 2017

      RickA

      What is the line between being wrong and being a denier.

      You exemplify it.

      You are wrong – constantly.

      You are corrected, sometimes at length and in detail, constantly.

      You keep repeating your wrong crap despite the explanations why it is wrong/

      That’s denialism.

      Now stop the whiny tone-trolling and RTFL at # 30.

      I don’t want to hear another word out of you until you have actually bothered to educate yourself to the point where you can see your own mistakes.

    36. #36 Windchasers
      April 6, 2017

      But the first 1% does not have the same effect as the current 1%, because of the log effect. The effect of the 20 ppm from 280 to 300 is not the same as the effect of the 20 ppm from 380 to 400. I am sure you know that, so I guess I don’t understand what you mean by the sentence I quoted.

      You’re kinda hopping horses midstream here. Percents work with log scales; they’re multiplicative increases. Parts per million are not.

      Here:
      If you add 20 ppm to 280 ppm, you’ve increased by 7.1%.
      If you add 20 ppm to 380 ppm, you’ve increased by 5.2%.
      The parts per million stayed the same while the percentage changed. The same would go for getting the same percent increase; 7% of 380ppm is more than 7% of 280ppm.

      Or, another example: if you double your CO2, you’ve increased it by 100%. The best estimate is that that would warm the Earth by ~3C. If you double it *again*, then you’ve again increased by 100%, which should have about the same effect.

    37. #37 RickA
      United States
      April 6, 2017

      I am sure I am mixing apples and oranges.

      The relationship between carbon dioxide and radiative forcing is logarithmic and thus increased concentrations have a progressively smaller warming effect.

      ln(C/C0) Where C is the current amount of CO2 in the atmosphere and C0 is the reference amount (280 ppm).

      So ln(1) is zero. ln(2) (a doubling) is .693 and our current level is ln(405/280) = .3688.

      But the formula always uses 280 ppm in the denominator.

    38. #38 MikeN
      April 6, 2017

      RickA, what Greg is saying is that the first 1% is stronger not because of the logarithmic effect, but that it happened 100 years ago. The radiative forcing stays in place for 100 years, and thus is 100x more than a 1% gain that happened last year.

    39. #39 Greg Laden
      April 6, 2017

      RickA: Yes, above some amount (less than half of the pre-industrial) the simplest version is that the effect reduces, so that first 1% of industrial CO2 pollution will have a larger effect than the same amount of CO2 when there is already 400ppm

      However, the actual long term effect on surface warming ends up being linear anyway because of other factors.

      But, the point I’m making is simpler: Whatever effect a unit mass of CO2 might be and how that might be shaped by the ambient concentration of CO2 at the time it is added, or feedback effects being enhanced or diminished, that earlier CO2 has had a century (or whatever) to do its work on the atmosphere.

      The reason I pointed this out is that you were going down that “skeptical” rabbit hole of assuming that human effects on climate change, including the release of greenhouse gas pollution and the freeing of fossil Carbon, has only been happening recently. It has, in fact, been happening since the late 18th century. A few decades of very early coal burning followed by a couple of centuries of affecting the atmosphere is not something to shake a stick at.

    40. #40 RickA
      United States
      April 6, 2017

      Thanks for the clarification.

      I understand your point.

      It is my understanding that even though humans had some impact on the climate pre-1950, that the IPCC is not willing to say it is more than 50% of the impact.

      In other words – before 1950, humans had some impact, after 1950, humans had more than 50% of the impact.

      And then they go on to say that all of the observed warming post 1950 (.65C or so) is caused by humans.

      But they are only talking about post 1950.

      We don’t have a similar statement that I am aware of for pre-1950.

    41. #41 BBD
      April 6, 2017

      But they are only talking about post 1950.

      We don’t have a similar statement that I am aware of for pre-1950.

      If you want to propose that some of the ~1C present warming was caused by natural forcing change pre-1950, then you need to explain why that warming has persisted until the present.

      Remember, this is about energy accumulating in the climate system. It radiates to space, so the *all* the inputs need to be maintained or it will cool.

      Either the pre-1950s natural forcings are still operating at full effect, or the anthropogenic forcing change post-1950 was itself sufficient to maintain a warming trend all the way to the present ~1C.

      I can show you CO2. What can you show me about mystery forcings?

    42. #42 Greg Laden
      April 6, 2017

      RickA, probably true, that the IPCC does not say anything much about pre 1950 human impacts.

      There was impact, however.

    43. #43 BBD
      April 6, 2017

      There was impact, however.

      I wonder what Rick will make of
      Ruddiman, Kutzbach & Vavrus (2011)
      Can natural or anthropogenic explanations of late-Holocene CO2 and CH4 increases be falsified?

      It certainly surprised me.

    44. #44 RickA
      United States
      April 6, 2017

      BBD #41 asks about “mystery forcings?”

      I think the warming of .7C from 550 to 950 AD is pretty mysterious.

      I think the .8C cooling from 950 to 1700 is pretty mysterious.

      http://agbjarn.blog.is/users/fa/agbjarn/files/ljungquist-temp-reconstruction-2000-years.pdf

    45. #45 Kevin O'Neill
      United States
      April 6, 2017

      RickA – that’s extra-tropical northern hemisphere only. We see even weirder regional fluctuations if we look long enough. Compare various regions of the arctic during the Holocene Climate Optimum; beacg ridges on Greenland (obviously a lot less coastal ice and warmer temperatures), but other areas (like Ellesmere Island – right next door) show cooler temperatures and more ice than today.

    46. #46 Marco
      April 7, 2017

      “pretty mysterious”.

      Maybe it’s time you accept that you simply don’t know enough to have a qualified opinion?

      The further back we go, the more difficult it is to have accurate measurements of the forcings. We don’t have that problem right now, unless there is some kind of completely nonunderstood forcing that just happens to do the same, and in the same direction, as what physics tells us increasing GHG concentrations are doing.

      Betting on something we don’t know is a high-risk endeavor. Yes, we may have a high-gain in the end, but we more likely are going for ruin. It might be nice if you could qualify all your “OMG, it’s all so uncertain” with “I am very aware that I holding on to a tiny straw that may well doom us all, but I prefer to keep holding on to that tiny straw, because I just don’t want to spend money on something right now, even if all evidence so far points to that money being well-spent on preventing major trouble in the foreseeable future”.

    47. #47 RickA
      United States
      April 7, 2017

      Marco #46:

      Oh – you thought I was a climate scientist, speaking with authority?

      Well that is not the case.

      I do not know enough to have a qualified opinion.

      Mine is merely a lay opinion.

      An opinion of someone who reads the science and is skeptical of what some of it says.

      What these temperature excursions of .7C and .8C over hundreds of years show is that natural forcing doesn’t always cancel out on a decade basis as is commonly raised in these discussions.

      Some natural forcing takes place over century and probably millennial time periods.

      We don’t know a lot about the climate and what changes it, over what time periods.

      In an effort to blame humans for all warming over the last 250 years, we are ignoring natural forcing and minimising it to score political points.

      Eventually science will correct this and that will cause ECS and TCR to drop lower in their existing range (which is happening already over the last 10 years).

      But I do want to be clear – I am not speaking from a position of authority and never have.

      This is merely my opinion.

    48. #48 Greg Laden
      April 7, 2017

      RickA 44:

      That reconstruction shows the normal range of variation that we are currently departing from (for reference, they show that departure in one of the figures, IIRC).

      It is a partial hemispheric reconstruction, i.e., part of one hemisphere, not the global surface temperature, so the comparison to the surface temperature record without noting that is problematic.

      The cause of those variations? That is, in my view, where some of the most interesting research is currently happening or will happen in the next five years or so in the area of climate science, other than things that have to do with ice. Secular variation and multidecadal variation is at that interesting point where we know enough to be able to suspect that we can know a lot more given more research. Very exciting.

      Not sure what your point is, though, vis-a-vis global warming. It — multidecadal and secular scale variation — is certainly very important in a discussion of climate change, but it is a bit above your pay grade. (No offense intended but cherry picking a squiggle on a graph is baby-level denialism, RickA!)

    49. #49 Christopher Winter
      April 7, 2017

      Marco puts it well. I’ll add that the attitude he describes is not a scientific attitude. I think every competent scientist would agree that there might conceivably be some undiscovered factor that causes the change we now attribute to the increasing concentration of carbon dioxide in Earth’s atmosphere.

      But that same scientist would point out that the preponderance of evidence we have now tells us that carbon dioxide is the chief culprit. If policymakers argue against acting on that evidence, they are being unscientific — that is to say unrealistic. Yet that is exactly what the House Science Committee is doing.

      Unless and until some real, valid evidence of that Mystery Climate Forcing (MCF) emerges, by attempting to tear down the credibility of mainstream climatologists the House Committee is derelict in its duty to uphold the standards of science.

    50. #50 Christopher Winter
      April 7, 2017

      Greg writes, “As Dan implies, the gang of three deniers, and a few others, have been before this and other panels in the US Congress again and again.”

      Indeed. It would be interesting to compare the numbers of witnesses from what I’ll call the contrarian camp to those from the mainstream, and the amounts of time given to the two sides for testimony.

    51. #51 Kevin O'Neill
      United States
      April 7, 2017

      RickA “What these temperature excursions of .7C and .8C over hundreds of years show is that natural forcing doesn’t always cancel out on a decade basis as is commonly raised in these discussions…. Some natural forcing takes place over century and probably millennial time periods.”

      Sorry, I had *already* pointed out that your reference is an extra-tropical NH only reconstruction. It’s not global.No one should be surprised at regional variations larger than global variations.

      You really don’t think these things through much, do you?

    52. #52 Wow
      April 7, 2017

      “Or, another example: if you double your CO2, you’ve increased it by 100%. The best estimate is that that would warm the Earth by ~3C. If you double it *again*, then you’ve again increased by 100%, which should have about the same effect.”

      “Dick” doesn’t get maths. Even grade-school maths. The main line of evidence that his claim to be a professional engineer is bogus and he’s likely only an oil-wiper.

    53. #53 Wow
      April 7, 2017

      “I think the warming of .7C from 550 to 950 AD is pretty mysterious.”

      So you don’t know what did it.

      So you don’t know that it’s still in effect.

      Yet we DO know what CO2 does and how much it’s increased.

      What is mysterious is why you think (for want of a better word) you have found any rationale for denial.

    54. #54 Marco
      April 7, 2017

      “Oh – you thought I was a climate scientist, speaking with authority?”

      Your use of the word “we” betrays you, RickA.

      You cannot write:
      “We don’t know a lot about the climate and what changes it, over what time periods.”

      You can only write:
      “I don’t know a lot about the climate and what changes it, over what time periods.”

      You are not skeptical, but pseudoskeptical, since you yourself admit that you do not have the expertise to have a qualified opinion!

    55. #55 Wow
      April 7, 2017

      Good catch.

      He wants to pretend a legion for his claims, but when asked to show his proofs, he wants to beg off as being a simple lone querant.

      Either speak for yourself or speak for a group, don’t fuck about and pretend to be both as seems convenient.

    56. #56 BBD
      April 7, 2017

      What a lot of evasive waffle from RickA. Again.

    57. #57 Russell
      Cambridge MA
      April 7, 2017

      Mann sparred directly with Smith, highlighting a Friday article in Science magazine that criticized Smith for speaking at a conference for climate change skeptics. Science magazine is published by the American Association for the Advancement of Science.

      “That is not known as an objective writer or magazine,” Smith said.

      Greg notes:

      Mann replied, “Well, it is ‘Science’ magazine.”
      This part, which is also discussed in the above referenced piece at the Guardian, was amazing. When Smith called the United State’s primary science journal a biased source, I could hear the sound of jaws dropping in unison across the world.’

      In an E-mail exchange last year, our new AAAS ,CEO, a former Democratric Congressman aroused my curiousity when on being reminded that 93% if AAAS Congresssional Fellows work for his political cohort, he assertd that the body was ” non-partisan, not bipartisan.”

      I then ventured to ask if he could find 10 Republicans within 100 feet of his office ( The 12 story AAAS building spans 183,000 square feet.

      As her did not elect to reply, perhaps Gregg can venture a guess as to how many of that evidenttly endangered species have survived The War On Republican Scientists?

    58. #58 Christopher Winter
      April 8, 2017

      As her (sic) did not elect to reply, perhaps Gregg can venture a guess as to how many of that evidenttly (sic) endangered species have survived The War On Republican Scientists?

      Kerry Emanuel seems to be doing all right. I’m sure there are others.

      I would hope you also wrote to Lamar Smith to ask why he reflexively dismissed the criticism by calling Science a non-objective (i.e. biased) publication.

    59. […] The recent Congressional hearings at which the two of them testified (along with a full on denier whom I’m ignoring right now, and actual scientists Michael Mann) exemplify this problem they have. There they were, tooling along with their denial or uncertainty or ax grinding, questioning the science and the appropriate policy, sucking up to the Republicans on the committee … until suddenly, near the end of the hearings … WHAM!!!!! Game over. Like the hovering lake fly that believes the trout to be a benevolent god right up to the moment the trout sucks the fly into its gut. (Apologies to Terry Pratchett.) […]

    60. #60 Russell Seitz
      Cambridge, MA
      April 8, 2017

      58
      That has been my objective in dealing wiith his predecessors whenever I have testified on the Hill, and I look forward to the opportunity to query him as well.