The sensitivity of Richard Lindzen

Have we warmed as much as expected?

This is a repost from Skeptical Science.

Previously, in A Case Study in Climate Science Integrity, we qualitatively examined two errors which led the Universal Ecological Fund (Fundaci­on Ecol³gical Universal [FEU-US]) and Dr. Richard Lindzen to arrive at diametrically opposed, but equally wrong conclusions.  Here is Lindzen’s (emphasis added):

“According to the UN’s Intergovernmental Panel on Climate Change, the greenhouse forcing from man made greenhouse gases is already about 86% of what one expects from a doubling of CO2 (with about half coming from methane, nitrous oxide, freons and ozone), and alarming predictions depend on models for which the sensitivity to a doubling for CO2 is greater than 2C which implies that we should already have seen much more warming than we have seen thus far

In both publications, thermal inertia and negative forcings were neglected.  Both performed calculations which accounted for the positive anthropogenic forcings (carbon dioxide, methane, and other greenhouse gases), but neglected these two factors.  The difference is that while the FEU-US completely ignored them, Lindzen did mention each factor in a halfhearted effort to justify neglecting them.  But before we get into the details, it’s worthwhile to examine the history of Lindzen’s “we should already have seen much more warming” claim.

A Brief History in Lindzen Time

Dr. Lindzen seems to have first made this argument in a 2002 letter to his local mayor in Newton, Massachusetts.

“the impact on the heat budget of the Earth due to the increases in CO2 and other man influenced greenhouse substances has already reached about 75% of what one expects from a doubling of CO2, and the temperature rise seen so far is much less (by a factor of 2-3) than models predict”

In 2005, Lindzen made the same argument in testimony to the UK Parliament House of Lords Economic Affairs Committee.  He later repeated the argument on National Public Radio (NPR) in 2006, again on NPR in 2007 in a public debate which included Gavin Schmidt and Michael Crichton, in an Energy & Environment-published paper in 2007, in an article in 2008, another article in 2009, and of course the 2011 article examined in the Case Study and re-published uncritically at WattsUpWithThat and many other “skeptic” media sources.  Suffice it to say, Lindzen makes this argument frequently.

Lindzen’s argument has also been rebutted several times, including by Coby Beck in 2006 and Stefan Rahmstorf in 2008.  Let’s examine the errors that these rebuttals have uncovered in Lindzen’s arguments.  Schwartz et al. (2010) agree that just based on greenhouse gas changes, ignoring all other factors, we “should have seen” 2.1°C warming above pre-industrial levels by now.  However, Schwartz et al. went on to quantify the other effects which Lindzen neglected, and so will we.

Thermal Inertia

Due to the fact that much of the Earth is covered in oceans, and it takes a long time to heat water, there is a lag before we see the full warming effects of an increase in atmospheric greenhouse gases (this is also known as “thermal inertia”).  In fact, we know there remains unrealized warming from the greenhouse gases we’ve already emitted because there is a global energy imbalance.  The amount of unrealized warming is dependent upon the amount of CO2 in the atmosphere (or other radiative forcing causing the energy imbalance) and the thermal inertia of the oceans (which causes a lag before the warming is realized).  Lindzen does briefly acknowledge thermal inertia in his UK Parliament testimony:

“the observed warming is too small compared to what models suggest. Even the fact that the oceans’ heat capacity leads to a delay in the response of the surface does not alter this conclusion.”

Unfortunately, Lindzen does not substantiate this claim, or provide any references to support it.  However, Stefan Rahmstorf does attempt to quantify the thermal inertia effect in his rebuttal:

“Data from about 1 million ocean temperature profiles show that the ocean has been taking up heat at a rate of 0.6 W/m2 (averaged over the full surface of the Earth) for the period 1993-2003 [21]. This rate must be subtracted from the greenhouse gas forcing of 2.6 W/m2, as actual warming must reflect the net change in heat balance, including the heat flow into the ocean.”

Rahmstorf references Willis et al. (2004), which found an oceanic warming rate of 0.86 ± 0.12 watts per square meter (W/m2) of ocean.  Given that approximately 70% of the Earth’s surface is ocean, this becomes approximately 0.6 ± 0.07 W/m2 of overall ocean heat uptake.  Schwartz et al. (2010) put the value at 0.37 ± 0.12 W/m2.  For our purposes, we’ll put the figure at 0.25 to 0.67 with a most likely value of 0.4 W/m2.  Let’s keep these numbers in our back pocket and move on to the second neglected factor.

Aerosols and Other Cooling Effects

Lindzen briefly addresses aerosols in his most recent article:

“Modelers defend this situation…by arguing that aerosols have cancelled [sic] much of the warming (viz Schwartz et al, 2010)…However, a recent paper (Ramanathan, 2007) points out that aerosols can warm as well as cool”

In short, Lindzen’s argument is that the radiative forcing from aerosols is highly uncertain with large error bars, and that they have both cooling (mainly by scattering sunlight and seeding clouds) and warming (mainly by black carbon darkening the Earth’s surface and reducing its reflectivity) effects.  These points are both accurate.

However, neglecting aerosols in calculating how much the planet should have warmed does not account for their uncertainty.  On the contrary, this is treating aerosols as if they have zero forcing with zero uncertainty.  It’s true that aerosols have both cooling and warming effects, but which is larger?

In his argument, Lindzen refers us to Ramanathan et al. (2007).  This study examined the warming effects of the Asian Brown Cloud and concluded that “atmospheric brown clouds enhanced lower atmospheric solar heating by about 50 per cent.”  The study also noted that, consistent with Lindzen’s claims about the aerosol forcing uncertainty, there is “at least a fourfold uncertainty in the aerosol forcing effect.”  However, this study focused on the warming effects of black carbon, and did not compare them to the cooling effects of atmospheric aerosols.

Ramanathan and Carmichael (2008), on the other hand, examined both the warming and cooling effects of aerosols.   This study found that black carbon has a warming effect of approximately 0.9 W/m2, while aerosol cooling effects account for approximately -2.3 W/m2.  Thus Ramanathan and Carmichael find that the net radiative forcing from aerosols + black carbon is approximately -1.4 W/m2.  This is broadly consistent with the IPCC net aerosol  + black carbon forcing most likely value of -1.1 W/m2:

Figure 1:  Global average radiative forcing in 2005 (best estimates and 5 to 95% uncertainty ranges) with respect to 1750.  Source (IPCC AR4).

Note that Lindzen’s assumed zero net aerosol + black carbon forcing is outside of this confidence range; therefore, neglecting its effect cannot be justified.  However, since the IPCC provides us with the 95% confidence range of the total net anthropogenic forcing in Figure 1, we can account for the uncertainties which concern Lindzen, and evaluate how much warming we “should have seen” by now.

Expected Forcing Effects on Temperature Thus Far

In fact, this is a simple calculation.  The IPCC 95% confidence range puts the total net anthropogenic forcing at 0.6 to 2.4 W/m2 (Figure 1).  On top of that, as discussed above, ocean heat uptake accounts for between 0.25 and 0.67 W/m2.  Therefore, subtracting the ocean heat uptake, the total net anthropogenic forcing over this period is somewhere between -0.07 and 2.15 W/m2, with a most likely value of 1.1 W/m2.

A doubling of atmospheric CO2 corresponds to a radiative forcing of 3.7 W/m2, according to the IPCC.  Therefore, the net anthropogenic radiative forcing thus far is between approximately 0% and 58% of the forcing associated with a doubling of atmospheric CO2, with a most likely value of 30%.

In order to be thorough, we can also include the natural radiative forcings.  Most have had approximately zero net effect since 1750, with the exception of the Sun, which has had a forcing of 0.06 to 0.30 W/m2 with a most likely value of 0.12 W/m2 over this period (Figure 1).  Therefore, net forcing since 1750 is approximately 0 to 2.45 W/m2, with a most likely value of 1.25 W/m2.  Thus the total net forcing thus far is between 0% and 66% of the forcing associated with a doubling of atmospheric CO2, with a most likely value of 34%.

What Does This Tell Us About Climate Sensitivity?

So far, global surface air temperatures have increased approximately 0.8°C  in response to these radiative forcings.  Since we’re 0% to 66% of the way to the radiative forcing associated with a doubling of atmospheric CO2 (most likely value of 34%), the amount we should expect the planet to warm if CO2 doubles (also known as “climate sensitivity“) has a most likely value of 2.4°C, with a minimum of 1.2°C (because of the large aerosol cooling effect uncertainty and the fact that we may only be 0% of the way to the doubled CO2 forcing, we can’t place an upper limit on the climate sensivity parameter with this calculation).   Using a much wider range of evidence, the IPCC puts the likely climate sensitivity range to a doubling of CO2 at 2 to 4.5°C with a most likely value of 3°C.  Our calculation is consistent with the IPCC range.

How Much Warming Should We Have Seen?

We can also flip the calculation backwards, assuming the IPCC most likely climate sensitivity of 3°C for a doubling of atmospheric CO2 and using the numbers above.  In this case, we should have seen from 0% to 66% of 3°C, or about 0 to 2.0°C.   Clearly the amount of warming we have seen so far is well within this range.  Additionally, the most likely amount of warming is 34% of 3°C, which is 1.0°C.  In other words, we have seen very close to the amount of warming that we “should have” seen, according to the IPCC.

Warming is Consistent with What We Expect

In short, contrary to Lindzen’s claims, the amount of surface warming thus far (0.8°C) is consistent with what we “should have seen” based on the IPCC numbers.  Moreover, this calculation puts the most likely climate sensitivity parameter value within the IPCC’s stated range, whereas the much lower value claimed in Lindzen and Choi (2009) (less than 1°C for CO2 doubling) is inconsistent even with our calculated climate sensitivity lower bound (1.2°C).  For additional discussion of the errors with Lindzen and Choi (2009), see here.

When we actually account for thermal inertia and negative forcings, we find that the amount of warming we have seen is consistent with what the IPCC would expect, but inconsistent with Lindzen and Choi 2009.  Thus the correct conclusion is that if Lindzen is correct about low climate sensitivity, we should already have seen much less warming than we have seen thus far.

This is a repost from Skeptical Science.

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27 Responses to The sensitivity of Richard Lindzen

  1. Mike Roddy says:

    When the history of climate policy is written, Richard Lindzen will be considered one of the most damaging actors. His papers about climate sensitivity, cloud feedbacks, and so on are resoundingly debunked by his peers before the ink is dry, but they survive on Fox and in oil company think tanks.

    This is a man who kept a straight face while telling large gatherings that smoking does not cause cancer. It would be too horrifying to take a journey into his head and figure out how it functions, but the public needs to know that every word out of his mouth should be followed by the “delete” button.

  2. Blame MIT.

    It is both a feature and horrible trap of the academic world that it retains professors based only peer reviewed, formally published documents. It means that professors like Lindzen can speak freely off balance in the real world, yet return to a comfy professorship at MIT to teach or research.

    Outside the university, professors are free to stupidly blather on anything — even their own topics in their own field – secure that whatever they say will not affect their tenure. That freedom comes because they are not speaking in formal academic publications.

    MIT should be horribly embarrassed by having a professor like Lindzen. And if they bothered to read the letters of outrage, they know of his gamesmanship and distraction. Lindzen keeps his academic nose clean by carefully selecting research projects and publishing rigorously written papers all within the university confines. This leaves him free to go wild in other areas. Like getting hired by Western Fuels Association as a witness for the obfuscation – or speaking before Congress – check YouTube. I get my information about him from DeSmogBlog database and from Wikipedia. (be sure to read the discussion section of his entry

    It is getting easier to for the world to recognize horribly unethical intellectual behavior, too bad MIT cannot respond to their errant academic.

    Shame MIT.

  3. Mark S says:

    Great post. Well written, clear and to the point. Skeptical science is a must read website for people of all levels who with to get acquainted with the scientific arguments surrounding climate change.

  4. Scrooge says:

    Well at least we can give deniers credit in their gish gallop. This is one area where we would like a better understanding.
    To believe Lindzen you still have to really squint your eyes. But you may not need as much magic to believe.

  5. Mark Shapiro says:

    OT, but I’ll venture that you have thoughts on NYT’s full page article on Cuccinelli’s “crusade” against climate science. Joe — I have some free advice: relax. Take a deep breath. Look outside your window for a moment. And then remember your love of rhetoric. Irony and metaphor, Lincoln and Shakespeare.

    There is a good piece waiting to be written about Cuccinelli. it will use irony, perhaps metaphor, and it will not mention head vises. Maybe it will focus on Cuccinelli’s “research”, or on his “basic reading”. I’m sure that the good AG from Virginia is only interested in The Truth. Why, he says so himself!

    I do admit, however, to fantasizing about cross-examining Cuccinelli . . . so tell the Court, what is your scientific background? Have you read Tyndall? Fourier? Arrhenius? Callendar? Keeling? Schneider? IPCC? NAS? . . . ?

    It could take a while.

  6. Jim says:

    In an interview with MIT Tech Talk published on September 27, 1989, Lindzen said, “I argue that the greenhouse effect does not seem to be as significant as suggested.” Twenty-two years of accumulating scientific evidence have left his assessment unchanged. That would be a pretty good definition of someone who bases his conclusions on ideology, not science.

  7. Dana says:

    Cool, thanks for another repost, Joe. And thanks to Mark S in comment #2 also.

  8. Will G. says:

    Joe – $100 a barrel, MSNBC reporting!

  9. Guy Who Doesn't Understand says:

    “Therefore, net forcing since 1750 is approximately 0 to 2.45 W/m2, with a most likely value of 1.25 W/m2.”

    “The IPCC 95% confidence range puts the total net anthropogenic forcing at 0.6 to 2.4 W/m2 (Figure 1). On top of that, as discussed above, ocean heat uptake accounts for between 0.25 and 0.67 W/m2. Therefore, subtracting the ocean heat uptake, the total net anthropogenic forcing over this period is somewhere between -0.07 and 2.15 W/m2, with a most likely value of 1.1 W/m2.” (including the Sun it would be -0.01 to 2.45)

    Perhaps I should ask this on the climate-science site. Does this mean that it is remotely possible (though not likely) that net anthropogenic forcing is actually a cooling effect? I find it hard to believe that such a result could be part of the math range, but is it?

    Do we simply conclude that it must not be negative despite the math because of the empirically observed trends (all other factors that could explain the variance notwithstanding)?

    “Since we’re 0% to 66% of the way to the radiative forcing associated with a doubling of CO2…” …Is the rest of this carbon forcing just lagging presently, but still expected to happen? I’m assuming that there’s nothing left out there that can sequester the ‘lagging’ carbon contribution, right?

  10. MapleLeaf says:

    Originally posted at Deltoid, but relevant to this article:

    “And here we have an example of none other than Lindzen coaching Watts on how to cherry pick data to hide the warming trend. The other day DeepClimate posted a story about Lindzen’s role in the ” skeptics’ ” questions put forward to Phil Jones by the BBC. DC, quotes an email that Lindzen sent to Anthony Watts in March 2008 (DC provides a link) in which he says:

    “Look at the attached. There has been no warming since 1997 and no statistically significant warming since 1995. Why bother with the arguments about an El Nino anomaly in 1998? (Incidentally, the red fuzz represents the error ‘bars’.)
    Best wishes,


    Richard S. Lindzen
    Alfred P. Sloan Professor of Atmospheric Sciences
    MIT Cambridge,
    MA 02139 USA”

    The DC story is at:

    This is what I, MapleLeaf posted at DC:
    “What I neglected to mention the other day, and this is perhaps what really needs to be emphasized, is that Lindzen is not operating in good faith. He has divorced himself with the science and that email to A. Watts is scary, b/c that is not how a reputable scientists in the search for truth thinks. This is LindzenGate. He is trying to hide the incline while at the same time his ilk are [falsely] accusing the CRU of fudging the data. Here Lindzen is explaining to Watts how to fudge the data [edit, OK, fudge is probably too strong a word] to avoid getting statistically significant warming. As andrew pointed out above, they can apply this tactic ad infinitum and continue to deceive the masses.”

    Can you imagine the uproar from the denier camp had Hansen, for example, sent such an email?

  11. Joan Savage says:

    Thanks to dana1981 who authored the piece from Skeptical Science. Short descriptions of the bases for rebuttal are very, very much appreciated.

    Richard Pauli (#2) touched on the issue of academicians who use, and are used for, their credentials, without accountability for their statements.
    A climate change equivalent of the 1860 Oxford evolution debate could be useful to clear the air, if I can be allowed a wonderfully horrible pun.

  12. Berbalang says:

    I noticed that gas here had jumped up another 20 cents a gallon. I had wondered what had happened in the news.

    The past few days I have been looking on-line for sources of head vices and sock puppets, both to be used when talking to deniers. Admitedly the head vice would also be used when dealing with some other stupidity.

    Mike Roddy @ 1, you are right about how horrifying it would be. We have this expectation that the same sort of thought processes that go on in our mind also go on in other peoples. We then find out that is not the case with some people. Those people can take extreme pleasure in the human suffering and death they cause.

  13. Mulga Mumblebrain says:

    It is plain the Lindzen contrives to arrive at a predetermined result. Perhaps connives as well. This is the essence of the Right’s ‘faith-based science’-we know the results that God or the Kochtopus have ordained, so the facts will be fitted to the Holy Purpose. Facts are, after all, infinitely plastic, and the audience are not other scientists, lost to their purposes by steadfast resistance to abandoning principle and integrity, but, rather, the Dunning Kruger mob, too stupid to understand how they are being led astray. So we proceed, merrily on our way to destruction, led like lambs to the slaughter, by the light of ‘perverted science’. The question now is not how the knowing denialists act, but why? Why, when from these deliberate manipulations it is clear that they are knowingly dissembling and misrepresenting, are these handful of rogue individuals making more likely the end of humanity? I suspect a deep and carefully camouflaged misanthropy.

  14. Colorado Bob says:

    “Look at the attached. There has been no warming since 1997 and no statistically significant warming since 1995.”

    Insurance Company Ranks 2010 among Worst Years Ever for Climate Disasters

    Climate change is a culprit in the long list of catastrophic natural disasters in 2010, according to insurance company Munich Re

  15. Dana says:

    Guy #9: ” Does this mean that it is remotely possible (though not likely) that net anthropogenic forcing is actually a cooling effect?”

    Not exactly. The negative value takes the ocean heat uptake into account, treating it as a negative feedback. But it’s not anthropogenic, it’s just delaying the realization of the anthropogenic warming. By itself, the net anthropogenic forcing is definitely positive.

    “Is the rest of this carbon forcing just lagging presently, but still expected to happen? I’m assuming that there’s nothing left out there that can sequester the ‘lagging’ carbon contribution, right?”

    Mostly right. Eventually (once atmospheric CO2 stabilizes), the planet will reach an energy equilibrium, at which point the oceans will stop slowing the warming process. Then the ‘unrealized’ surface warming will become ‘realized’. We’re not talking about ocean carbon uptake here, we’re talking about ocean heat uptake.

  16. Joan Savage says:

    Dear Mulga (#13)

    Academia in the US occasionally produces doctorates that are incomplete, even deficient, in the set of analytical skills needed for the respective fields. The affected Ph.D.’s are loathe to admit their diminished capacity.

    You credit the climate change deniers with an organized or conscious intent, but there may be plain old mediocrity in the mix that could explain some of the flawed reasoning.

  17. David B. Benson says:

    I’d say Lindzen is quite insensitive.

  18. Mulga Mumblebrain says:

    Joan Savage #16, I take your point, but I’m still convinced that much denialism, whether of anthropogenic climate disruption or any of the plethora of other ecological catastrophes, ALL of which, every last one of them, the Right denies, is driven by deep and savage misanthropy. I am convinced that the character structure of certain Rightwingers contains within it a desire, whether conscious, unconscious or sublimated, to see humanity destroyed. One can speculate whence such psychologies arise, and how and why, but I’m certain that they exist. And I’m also convinced that a perverted, apocalypticist type of religious belief also encompasses such hatred of this world and such preference for an imagined transcendental Nirvana about to descend from on high, that it is determined to give the End Times a little helpful nudge in the right direction. Or a great big shove.

  19. Zetetic says:

    @ Joan Savage #16:
    Respectfully, I must disagree with your charitable assesment of Lindzen.

    His earlier scientific work seems to have been respectable. But due to his support of both the tobacco industry and the fossil fuel industries (with financial ties to both), I suspect that his motives are far more mercenary (and perhaps ideological) than due to his competence.
    SourceWatch- Richard S. Lindzen

  20. riverat says:

    It’s good to have guys like Lindzen and Spencer around. As people with acknowledged training in the field and obviously a contrarian mindset (to put it kindly) if they can’t offer up a convincing argument against current theory it just strengthens it.

  21. Edward says:

    18 Mulga Mumblebrain: Roger that. Which is why we need help from the psychology and psychiatry departments. Proper, I mean correct, name calling would help our cause a lot. We need to know all about such strangely twisted people to be able to counter them. We need to understand their effect on us and other people as well.

  22. GerryC says:

    Am I right in assuming Dick is pretty close to getting his new paper published in the peer-reviewed media, hence the need to attack pre-emptively?

    Potentially curious timing on this one.. time will tell.

  23. Dana says:

    GerryC – the timing was due to the fact that Lindzen published a media article on this subject a few weeks ago, which is what I was responding to. I have no idea about his publication schedule.

  24. Zetetic says:

    @ GerryC:

    Even Dembski has managed to get papers published in peer-reviewed media. In Dembski’s case all he did was make an argument that did nothing to advance so-called “intelligent design” and never it received much attention from the scientific community since it was more of the same-old-same-old.

    Somehow it’s unlikely that any new work of Lindzen’s will be much different in advancing his efforts against AGW. But who knows, maybe he might surprise us? I doubt it though.

  25. Roger says:

    I’ve spoken to several people at MIT, including Lindzen colleagues and the president, Susan Hockfield, about this sad situation. They are afraid that the forces of evil (my wording) will find a way to make things worse if Dick’s freedom of speech is somehow denied. I say that the special circumstances demand that they try to figure out a way.

  26. Zetetic says:

    @ Roger #25:

    Maybe I’ve misunderstood the intent of your comment, but I don’t see any need to deny Lindzen’s “freedom of speech”. I tend to agree that such an action would only make him a “martyr” among the less informed public.

    On the other hand, I don’t see why an association such as MIT needs to allow such a person to drag their reputation “through the mud” from his insistence on defending big business interests at the cost of public health and safety.

    Censoring him will let the denialists cry “Help! Help! We’re being oppressed!”, and not without some justification. But a prestigious institution (such as MIT) disassociating themselves from him will only hurt his reputation while improving theirs, at least among everyone but the denialists.

    I say (IMO) that his work should be publicly peer-reviewed so that it can be fairly critiqued in public. But that doesn’t mean that MIT can’t find a way to wash their hands of him, and explain why to the general public.

  27. realist says:

    VA’s attorney general is an embarrassment to the Commonwealth and should be recalled. His law degree is from George Mason University which boasts of a Koch on its board of visitors and S. Fred Singer as adjunct professor.