Knee in the Curve or Calm Before the Storm?

Notwithstanding the efforts of scientists like Kevin Trenberth to make us believe otherwise, impacts of climate change to date are very difficult to discern. Although temperatures today average about 1C more than they did in 1850, it hasn’t changed the number or intensity of storms, droughts and probably not for floods. We are not inundated by either sea level rise or climate refugees. As temperatures have climbed, so have agricultural yields. However, the number and intensity of conflicts have gone way down.

A minor debate occurring now in the climate blogosphere is tangentially related to this. Roger Harrabin, writing in the BBC, quotes Richard Tol as saying “Most people would argue that slight warming is probably beneficial for human welfare on net, if you measure it in dollars, but more pronounced warming is probably a net negative.” In this, Tol is merely echoing the IPCC–or quoting himself, as he was a lead author for the IPCC’s section on the subject.

The question is when do the benefits of warmer climate begin to be outweighed by negative impacts? Harrabin and Tol go back and forth on this, and have gone back and forth since the story’s publication in the climate blogosphere.

As near as I can tell, what Tol is arguing is that a warming climate shows net benefits up to 1C temperature rise–what we have now. He believes that the negative impacts of climate change will clearly outweigh those positives when it gets to 2C temperature rise. This leaves a grey area between the two levels–and given the state of the science, that seems reasonable.

In fact it would be reasonable, given what temperatures have done since 1945 (when human contributions of CO2 are held to have begun on a large scale) that there will be periods of time between the realization of 1C and before we hit 2C that will be benign, and periods of time that will see sharp negative impacts.

A more germane question might be ‘How long a period will we see between a 1C temperature rise and a 2C temperature rise?’

As Tol accepts the IPCC mid-range estimate of 3C, he thinks it will be relatively early in the century. As a Lukewarmer with a more modest view of sensitivity (I think it will be about 2.1C), I think we have a little more time.

But because my calculations show energy consumption (and fossil fuel usage) rising much more than do the International Energy Agency, British Petroleum, the World Bank, the IMF and the Department of Energy’s Energy Information Administration (gulp–that’s a lot of smart people I’m disagreeing with), the grace period won’t be as long as we would all like.

I think the worm turns in 2075. At which point what Kevin Trenberth is saying will become cogent and salient. Which is why I wish he and others would quit crying wolf.

Because I believe the wolf will come. The next 60 years are essentially the calm before the storm.



21 responses to “Knee in the Curve or Calm Before the Storm?

  1. Perhaps we should look in more detail at what actually has happened to temperatures since 1945 when apparently anthropogenic CO2 output was large enough to have an effect.

    1940-70 – 30 years of mild decline followed by just a 18 year rise mirroring that of the period of approx 1910 – 1940 and since then a standstill/microscopic rise/fall for now almost 20 years mirroring the period 1940-1970.

    Whatever the effects of rising temperatures, positive or negative this pattern does not in any way mirror in the curve of increasing anthropogenic CO2 generation which is still pitiably small compared to the whole system wit it’s churn rates of less than 5 years.

    And further all of CO2 is just a small proportion of total greenhouse gasses in our atmosphere.

    Sometimes we get lost in our overblown sense of importance and loose sight of the relative size of the natural world on earth and in the solar system. Svensmark has shown that we are subject to measurable influences from not just the closest star that provides virtually 100% of our energy but from stars further away.

    And that sense of puffed up importance leads some of us to take the difference between the differences between Harrabin and Tol’s opinions seriously.

  2. Tom, I do not know if you have seen this but it looks like Tasmin Edwards has radically changed the cost-of-climate-change equation by substantially lowering the risk (and height) of sea level rise.

    • Yeah, I’m reading it now. Good stuff. I like Tamsin.

      • I like her too but that will not prevent me from poking some good-natured fun at her. Her blog was called “All Models Are Wrong”, yet her study was based on – – – models.

      • Almost Iowa,

        No, Tamsin’s blog was called “All models are wrong, but some models are useful”. Nothing like the title you gave, except that both use some of the same words.

      • With all due respect to Tamsin and her co-authors, I don’t know why one would expect a model with such fundamental unknowns, extrapolated over 100 and 200 years, to be “useful” in a scientific sense. And those are only the “known unknowns”.

        In the political domain, however, it is useful as a counterpoint to those who would have us believe (based on other models with different assumptions) that the Antarctic is poised to deluge our coastal cities. Unless humanity makes huge changes, and fast. And even that might not avert disaster. [My own rather free translation of pre-Paris prattle.]

      • Sorry Mike. The title of Tasmin Edwards blog is All Models Are Wrong. The additional text “…but some are useful. A grown-up discussion about how to quantify uncertainties in modelling climate change and its impacts, past and future” is what is known as a subtitle.

        The url (before she moved to PLOS) was

  3. My personal hope is that Paris turns into a debacle that is the equivalent of a knee in the groin of climate hypesters and profiteers.

  4. I’ve taken a long look at the paleontology time series. I’m not convinced they have much to say in terms of temperature, sure wish they did. But if they really are temperature series, there is one thing that seems to be ignored; I’ve yet to find one that shows an upper limit to the benefits of warming. So I just don’t buy your scenario of damage even at high sensitivity. The opposite is also pretty evident lots of damage when cooling sets in. Seems reasonable to me that a warmer world sustains more total life and promotes diversity of life.

  5. Lukewarmers don’t think there will be a wolf, ever. Alarmists think that there is something like a wolf which, on close inspection, turns out to be a sheep.

    • Mr. Erren, what you say about Lukewarmers is not the case. Not for me, not for Steve Mosher, not for Lucia Liljegren. I don’t know how you formed that opinion.

      • Thomas you are extrapolating in a Malthusian way. It’s like 1915 when people were concerned about the horse manure problem in 1975.

      • That’s kind of funny, given that I am more of a Julian Simon kinda guy. But we are going to burn that much energy. I think it’s a problem.

        On Friday, 20 November 2015, The Lukewarmer's Way wrote:


      • Thomas,
        Arrhenius and Callendar were both lukewarmers as they expected, like I do, that the warming that is coming this century will be beneficial for mankind. Now if you are speaking of a wolf and a showing a picture of a threatening storm, then I simply cannot place you in the category of lukewarmers but instead of full blown alarmists.

        If I have done my sums correctly – and I think I have – It is clear that even under a very unlikely RCP8.5 emission scenario using a 1.3 transient climate sensitivity, the temperature will rise only a modest 1.5 degrees this century.

        Arrhenius, Callender and I think that is good news for mankind. That is why I call myself a lukewarmer. Why are you calling yourself a lukewarmer when you are crying wolf?

      • Mr. Erren, I should think it’s obvious. I consider myself a Lukewarmer because I believe sensitivity is in the lower end of the range offered by the IPCC. I think it’s a problem because if I have done my sums correctly, and I think I have, emissions will rise faster than most expect.

      • Tom,
        This goes back to your projections of energy use, which I believe are reasonable.
        Please also consider the values created and problems solved by producing so much energy.
        So far the ramp up in energy use has been almost entirely beneficial to humans- certainly vastly out weighing the costs.

    • Hans,
      Not to put words in Tom’s mouth, but as I understand it Tom thinks there are huge problems likely if the consensus prediction warming occurs.
      His books and his blog writing makes it clear that he is concerned about warming impacts.
      He is also (as I understand it) of the belief that the expected warming will be on the low side of the consensus range.
      To modify your metaphor, if you don’t mind I would try to restate it this way:
      Skeptics believe that if there is a climate wolf, it will be one that is not a new species nor one we had much to do with creating, and that there is little if any evidence a wolf is coming anytime soon.
      Lukewarmers believe there may likely be a wolf, and that we have fed it, but the wolf is a pup now and may be relatively tame in the future.
      Alarmists believe fervently that there is a climate wolf huffing and puffing away already. They have models of wolves. They have scary stories of wolves. They know this wolf is entirely human created. And they know that anyone who fails to see their wolf is not only but evil.

    • Hiya hunter, Yeah, no question that cheap energy has done us all a lot of good. But there are costs to cheap energy not reflected in the bills. And there can be too much of a good thing.

  6. My analysis shows crude oil production will be approximately flat over the next 20 years. Afterwards it will likely start dropping. I base my analysis on a country by country analysis and a pretty good understanding of the existing and developing recovery technologies.

    The ability to sustain production within 5 % of current levels is a function of oil prices & cost environment. I’m basing my estimate on $150 per barrel in 2015 US $.

    The wild cards or more known unknowns are Venezuela and Russia. Venezuela has huge oil resources, but the political environment is awful. It also suffers from a technical issue which is destroying reserves due to pdvsa mismanagement.

    In Russia’s case the wild cards are Arctic oil reserves in the Kara, Barents, and Oskhost, and the Siberian oil shales and tight rocks.

    Thus far I’m having a problem finding any cornucopians who are able to debate whether the world crude oil and condensate production will ever exceed 100 mmbopd, which is way lower than the 160 mmbopd used by the IPCC in RCP8.5.

    • Fernando,
      Since most oil is used for transportation fuels do you see a transition to hybrid and all electric drive trains compensating for any flat or decline in the production curve?
      Natural gas seems to be the fossil fuel we have squandered the most in some ways.
      A family member who lives in Venezuela and works for Petro Chavez thinks they have more oil than the Saudis, but he is repeating what he hears so I take that with a large grain of salt.
      We tend to strictly limit conversations to family and non-political topics when he comes to Houston on business….

      • Hunter, I see the market being taken over by whatever is cost effective. This means hybrids, small light weight vehicles, and possibly electric vehicles. But EVs lack range, are expensive, and will likely be limited to short range applications. I’m not into speculating about fantastic technologies, therefore when I see a competitive battery I’ll believe it.

        Regarding the Venezuelan oil, the bulk f the remaining oil is a very heavy, sulfur and metal laden crude identical to the Canadian crudes produced in Alberta. The oil in place is huge, but the recoverable amount is very low.

        I can’t get into technical details, but I believe I may be one of the top ten individuals with a full of deck of knowledge about that Venezuelan oil accumulation. Hell, I may be one of the top three.

        And I know things about it I can’t really discuss. But what I do know is that producing it will require a huge investment, and as of today the oil being produced is causing effects in the reservoir which will damage it permanently.

        Thus the current PDVSA management, if allowed to continue doing what they are, will lead to the loss of a huge volume of oil reserves.

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