Wednesday, 7 May 2014

What the U.S. National Climate Assessment Doesn’t Tell You

Everyone’s favourite leftie blogger at No Right Turn has breathlessly announced “the US government has released its National Climate Assessment, confirming that climate change is a clear and present danger to the United States.” Since he’s brought the White House’s paid assessment into the local blogosphere, allow to offer in response this Guest Post by climate scientists Patrick Michaels and Chip Kappenberger.

What the National Climate Assessment Doesn’t Tell You

The Obama Administration this week is set to release [and now has – Ed.] the latest version of the National Climate Assessment—a report which is supposed to detail the potential impacts that climate change will have on the United States.  The report overly focuses on the supposed negative impacts from climate change while largely dismissing or ignoring the positives from climate change.

The bias in the National Climate Assessment towards pessimism (which we have previously detailed here) has implications throughout the US federal regulatory process because the National Climate Assessment is cited (either directly or indirectly) as a primary source for the science of climate change for justifying federal regulation aimed towards mitigating greenhouse gas emissions [and by politicians here in NZ for similar reasons – Ed.]. Since the National Climate Assessment gets it wrong, so does everyone else.

A good example of this can be found in how climate change is effecting  the human response during heat waves.  The National Climate Assessment foresees an increasing frequency and magnitude of heat waves leading to growing numbers of heat-related deaths. The leading science suggests just the opposite.

Case and point. Last week, we had an article published in the peer-reviewed scientific journal Nature Climate Change that showed how the impacts of extreme heat are often overplayed while the impacts of adaptation to the heat are underplayed.  And a new paper has just been published in the journal Environmental Health Perspectives that finds that the risk of dying from heat waves in the U.S. has been on the decline for the past several decades.

By now, this should be rather unsurprising as it has been demonstrated over and over again. Not only in the U.S. but in Europe (and yes, Stockholm) and other major global cities as well.

The idea that human-caused global warming is going to increase heat-related mortality is simply outdated and wrong. In fact, the opposite is more likely the case—that is, a warming climate will decrease the population’s sensitivity to heat events as it induces adaptation.  We described it this way in our Nature Climate Change piece:

Some portion of this response [the decline in the risk of dying from heat waves] probably reflects the temporal increase in the frequency of extreme-heat events, an increase that elevates public consciousness and spurs adaptive response. In this manner, climate change itself leads to adaptation.
…Our analysis highlights one of the many often overlooked intricacies of the human response to climate change.

But this information often falls on deaf ears—especially those ears responsible for developing the NCA.

Here is what the Executive Summary of the draft version had to say about heat-related mortality:

Climate change will influence human health in many ways; some existing health threats will intensify, and new health threats will emerge. Some of the key drivers of health impacts include: increasingly frequent and intense extreme heat, which causes heat-related illnesses and deaths and over time, worsens drought and wildfire risks, and intensifies air pollution.

The U.S. Environmental Protection Agency takes the same outlook (of course since it is based heavily on the National Climate Assessment).  The EPA leaned heavily on heat-related mortality as one the “threats” to public health and welfare in its justification for pursuing greenhouse gas emissions restrictions. From the EPA’s Technical Support Document for its greenhouse gas “Endangerment Finding”:

Severe heat waves are projected to intensify in magnitude and duration over the portions of the United States where these events already occur, with potential increases in mortality and morbidity, especially among the elderly, young, and frail. [emphasis in original]

Now compare the Administration’s take with the latest findings on the trend in heat-related mortality across the United States as published by a research team led by Harvard School of Public Health’s Jennifer Bobb.   Bobb and colleagues found that the risk of dying from excessive heat events was declining across the U.S. And further, that most of the overall decline was coming from declines in the sensitivity to extreme heat shown by the elderly population (75 and older).  In fact, the Bobb team found that the risk in the older population has dropped so far that it is now indistinguishable from the risk to the younger populations. Adaptation is a beautiful thing!

From Bobb et al.:

While heat-related mortality risk for the ≥75 age group was greater than for the <65 group at the beginning of the study period, by 2005 they had converged to similar levels.

In other words, all the EPA’s talk about an increasing threat from heat waves and a growing elderly population combining to negatively impact the public health and welfare has been wrong up to now and almost assuredly will be so into the future as we continually look for ways to avoid dying avoidable deaths (e.g., those from heat waves).

Bobb and colleagues summarise this way:

This study provides strong evidence that acute (e.g., same-day) heat-related mortality risk has declined over time in the US, even in more recent years. This evidence complements findings from US studies using earlier data from the 1960s through mid-1990s on community-specific mortality rates (Davis et al. 2003a; Davis et al. 2003b), as well as European studies that found temporal declines in heat-related mortality risk (Carson et al. 2006; Donaldson et al. 2003; Kysely and Plavcova 2011; Schifano et al. 2012), and supports the hypothesis that the population is continually adapting to heat.

As a note, we (Knappenberger and Michaels) were co-authors on the two Davis et al. studies cited in the above paragraph. Our work, first published more than a decade ago, was some of the first research into the declining trends in heat-related mortality across the U.S.

Clearly we have been saying all this stuff for a long time and even more clearly, the federal government hasn’t been listening for a long time. It is not what they want to hear.

Patrick J. Michaels is the director of the Center for the Study of Science at the Cato Institute.Chip Knappenberger is the assistant director of the Center for the Study of Science at the Cato Institute, and coordinates the scientific and outreach activities for the Center. Robert C. Balling, Jr. is a professor of geography at Arizona State University. Mary J. Hutzler is a Senior Fellow at Institute for Energy Research. Craig D. Idso is the founder, former president and current chairman of the board of the Center for the Study of Carbon Dioxide and Global Change.
This post first appeared at the Cato at Liberty blog.


Bobb, J.F., R.D. Peng, M.L. Bell, and F. Dominici, 2014. Heat-related mortality and adaptation in the United States, Environmental Health Perspectives,
Davis, R.E., P.C. Knappenbergre, P.J. Michaels, and W.M. Novicoff, 2003a, Changing heat-related mortality in the United States. Environmental Health Perspectives111, 1712–1718.
Davis, R.E., P.C. Knappenbergre, P.J. Michaels, and W.M. Novicoff, 2003b, Decadal changes in summer mortality in U.S. cities. International Journal of Biometeorology,47, 166–75.
Knappenberger, P.C., P.J. Michaels, and A.W. Watts, 2014. Adaptation to extreme heat in Stockholm County, Sweden. Nature Climate Change, 4, 302-303.



  1. Plato's "noble" lie
    NZ Climate Science Coalition has the above interesting article; how the ends justify the means such that greens/the left feel easy about lying; and that their exaggerations and alarums have started to back-fire on them

  2. What does your average Libertarian believe with respect to global warming?

    1) Is the planet warming?
    2) Are human activities the main cause?
    3) Is warming a problem we should be worried about, or will adaption/technological change render it harmless?
    4) Are climate scientists generally honest (even if they're wrong about AGW) or part of an environmentalist conspiracy?

    I previously thought Libertarians went in for the "environmentalist conspiracy" theory, but this article is much more sophisticated. It's refreshing to have skeptics write on topics they are qualified for!

  3. No, No, No, and No/Yes (to both parts of question 4).

    I had a wonderful time on another website on Saturday with a Yank from Cleveland, Ohio hysterically talking about 'global warming' on one of the blogs on that site.

    I managed to bowl him out of the park, so to speak, and have vast numbers of people in several countries roaring with laughter when I gave him weather statistics for his own city.

    I pointed out the average February (the latest month with stats available) temperature for Cleveland during the 1990s was 31.3 degrees farenheit....during 2000 - 2010 it was 30.3 degrees farenheit.... and in 2014 it was....a 'global warming' 22.6 degrees.

    It is about the 30th time I have done something similar; there is nothing easier than humiliating global warming advocates and proving them wrong - all you have to do is give the stats for their own city.

  4. Sam: I'm not sure there is such an animal as an average libertarian. "We are all individuals!" "I'm not!" etc.

    I'm not at all a climate scientist, and so I try to avoid "believing" anything. That puts this particular libertarian in the skeptic bucket, as my default position is "it's real when you prove it is real, and the onus of proof is on the party making the assertion". That said, I don't much like being called a denier or told I'm an idiot when I voice this skepticism, so I tend to just shut up about it. I don't have the knowledge (or even interest) in this area to make a case either way and I get very annoyed with those on both sides claiming they do have all the knowledge.

    I do believe there's something of a conspiracy, though I don't think there's anything sinister in it. It's the same sort of well-meaning groupthink behind most coercive government policy. These people genuinely think they are saving us from ourselves. They're entitled to think that, I just wish they'd stop trying to limit the flow in my shower head, or dictate what sort of light bulb I may buy.

    The point about honesty is interesting when it comes to science. I know a lot of scientists, and several have told me that if you find something which might decrease your chances of receiving more funding, you generally shut up about it. And vice versa. Draw your own conclusions there... Not really a question of honesty, more of self preservation.

    I do wonder what exactly the hysterical "the world is ending" crowd would have us do about it even if man made global warming is proven to be a fact. I mean, good luck taming China, India, or other huge chunks of the world not willing to kowtow to the trendy whims of "western government". I'd suggest that even if the theory is eventually proven correct, then adaptation and technology are really the only options.

  5. Greig - I see what you mean about every libertarian being different, compare your thoughtful piece to the willful ignorance of Mr Lineberry's above! (Although he could be trolling, surely he didn't really win that argument by pointing out that 2014 was a cold winter for parts of the US?)

    I'd tend to agree with your prescription - I don't think democracy is equipped to handle this sort of issue, so we'd better hope we can adapt long enough for engineers to save us.

    I'm in the process of getting my PhD and you're right about the effects of incentives on research. Although remember they work both ways - the article cited above was written by scientists at the Cato Institute, who don't exactly have ideologically neutral funders (I don't mean to disparage the article, that it was published in Nature assures me it wasn't hackery).

    Basically, as someone who trust scientists but who's not a climate scientist, I've got to go with the consensus view. To hold any other opinion would surely reflect my ideological priors or what I'd like to be true. That's not to say that we shouldn't have dissenting climate scientists like Knappenberger, in fact dissenters are essential for science to function! It's just that those without the requisite qualifications should ask themselves why they trust the sources they do.

  6. Sam - you and others claim "global warming".

    I simply put that contention to the test by taking a random place (asking anyone in the world where they live) and checking the temperature statistics for that place over a long period of time - and without exception they have cooled this century.

    These are not my temperature statistics but those provided by the local weather office and collated on a website.

    You refuse to accept (under any circumstances) that falling temperatures do not meaning warming or increasing temperatures.
    You cannot provide any logical explanation as to how temperatures can fall every year for 15 years in a row and still believe in 'warming'.

    Perhaps it is you who is "wilfully ignorant".

    As for a cold US winter not being an indication of anything you are once again wrong because in 2004 you had everyone from Al Gore to various scientists saying "within 10 years..."

    What happened in 10 years? everyone froze their tits off! haha!

    Today various claims are being made "within 10 years..." and I guarantee in 2024 it will not have happened; someone (probably me) will point out things are cooling and the response from the truly ignorant will be "that proves nothing"

    In 2024 various scientists and others will say "within 10 years..." and in 2034 I will undoubtedly be able to show their claims amounted to fiction and some smartypants will say "that proves nothing"

    In 2034 various scientists and others will say "within 10 years..." and guess what I will be doing in 2044... (you get the general idea)

  7. "I've got to go with the consensus view."

    Now that is what is called thinking for oneself. An excellent example of a junior scientist in the making, one who'll fit right in.


  8. You "think" for yourself, Amit, and you've arrived at the conclusion that vaccines cause autism. Given the existence of fuckwittism, "thinking for oneself" is not an unmitigated good.

  9. Mr Lineberry - are you saying literally every place in the world has cooled this century?

    You probably think scientists are being weaselly when they hedge and describe events in terms of probabilities or give their predictions within a range, but you're very unlikely to find them making careless assertions like "without exception" (unless there are literally no exceptions).

    This century is obviously too short a period to measure anything significant, but I took your example of the cold Cleveland winter and found average winter temperature data here, fitted a (very weak) linear trend and found 0.17 degrees F warming per year. You can find monthly averages here, which show 0.07 degress F warming per year in January and 0.19 degrees cooling in February. The point is, none of this means shit! You can't get a trend for something as variable as the climate with 13-14 data points.

    Amit - Chaz is right. "Thinking for oneself" without the time or qualifications necessary to make sense of a complicated subject is a recipe for being wrong. I could do my PhD in climate science and forge my own strong opinion one way or the other, but I'm not. This is why I have no problem with dissenting climate scientists, they've done the research and earned the right to hold alternative views.

    The world wouldn't function if everyone had to do their own first hand research to hold a belief. Do you fly or go to the doctor? I trust that scientists/engineers know how to make planes fly, I trust that scientists/doctors (mostly) know how to treat illness, and I trust that climate scientists when they say that human action has, and will continue to have, effects on the climate detrimental to our well being.

  10. Sam - no I am not saying everywhere in the World has cooled....because I do not know.

    What I have done, since finding this website with weather statistics, is ask people where they live (if they claim 'global warming') and then look up the weather for that place over the last few decades.

    I have a very open mind on what the figures will show.

    So far I have done it on either 30 or 31 (lost count) different places all suggested at random by other people.

    What the figures show - without exception are the following -

    1. Things warmed up 'a bit' in the 1980s
    2. There was a clear warming in the 1990s (something everybody is agreed upon because it is true)
    3. A levelling out, or slight fall in the 2000s
    4. A clear cooling in recent times - the last 3 or 4 years
    5. When looked at over a long period (2000 - 2013) temperatures have cooled since the 1990s.

    The only qualification I would make to any averaging is I look at things in 'decades' (e.g I will start at 1980 and go to 1989 and find an average).

    The weather temperature figures are 'official' - ie: it is what Jim Hickey says on the news.

    Let me assure you, Sam, that far from being 'wilfully ignorant' I have a very open mind - I simply check the actual temperatures and find out what they were.

    It seems that 2007 was a reasonably hot year in most places, but by any measure it appears that temperatures are, and have been, cooling since a peak of 1998/99.

    (On a personal note - as someone who 'endured' Southland winters during the 1970s and 1980s - nothing would give me greater pleasure than that fine part of NZ to be having a large dose of 'global warming'; I am not the only born and bred Southlander who wishes the climate there was similar to Auckland HAHAHA!!)

  11. Mr Lineberry - If you think 2000-2013 constitutes a 'long period' on planet Earth then you really have no idea what you are talking about and should STFU.

  12. Ben - as Margaret Thatcher used to say "When an attack is particularly personal I rejoice - because it means they have no arguments left"

    I notice no attempt is made to deny cooling temperatures during that time period.

    But I shall let you into a secret Ben... (come closer; pull up a chair) ....2000 - 2013 is a considerably longer period than 1991 - 98 when the temperatures rose; not only that but the 1970s (when hysteria about a coming ice age due to falling temperatures was all the rage) is also longer than that brief 1990s warming period.

    So swear all you like but you cannot beat "truth" and "logic" - which is why we libertarians are superior people.

  13. Surely that last line is the smoking gun that Mr Lineberry is a brilliant satirist. Otherwise it's Poe's law in action

  14. Sam

    You confuse educational qualifications for knowledge. They are not the same.

    Belief is not the same as knowledge either.

    Nor is consensus.

    Keep on with the naive trusting and no doubt you'll express great surprise when your trust turns out to be misplaced and, figuratively speaking, reality cums in your mouth and then fails to respect you in the morning. Carry on like this and you'll find that in your entire professional life you'll contribute exactly nothing to the pool of human knowledge.

    Fact is, it is entirely correct for an individual to think independently. This is what reality and human nature demand. Following some consensus is a cop out. Now would be a good time to read some of what Ayn Rand has to say about the topic of knowledge and its acquisition.


  15. "Now would be a good time to read some of what Ayn Rand has to say about the topic of knowledge and its acquisition."

    Yeah, think independently and agree with Ayn Rand, everyone!


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