Lukewarming 2075-2100

Yesterday I sketched out a scenario for what I expect from global warming between now and 2075. It’s obviously hypothetical, but I think it plausible.

The post has attracted a number of commenters, some positive, some negative. However, nobody has noticed or put together the two sentences that should be blinking red and jumping off the page. Of course, I cleverly separated them. Let’s put them side by side here:

  1. I expect warming (from all human causes) to be 2C over the course of this century
  2. I forecast warming of 0.5C through 2075

It will be an interesting end to this century. Yes, I think anthropogenic warming from all sources could plausibly be about 1.5C in the last 25 years of the 21st Century.

The proximate cause of all that is a dramatic increase in energy consumption that will continue to surprise us throughout the next 87 years. I’ve been detailing all of that for more than a year on my companion blog 3000 Quads.

This is what happened in the United States as we developed:

history-of-energy-consumptionAnd this is what development and energy consumption look like for some developing countries by 2030:


The world used about 523 quads in 2010. I believe that figure will grow to 3,000 quads every year by 2075 and will then stabilize at that level through the end of the century. I again used a ‘lower math’ approach to the calculations that brought me to that conclusion, again so nobody would accuse me of fiddling with the statistics.

I won’t repeat all of the work I did over there, although if you want to read the paper I wrote on it it is here. The calculations driving my projections are energy consumption per capita, population growth and growth in GDP per capita. I looked at a lot of numbers and I’m pretty satisfied that I came up with a reasonable answer.

I got some validation for my thinking this morning, reading a paper titled “Medium And Long-Term Scenarios For Global Growth And Imbalances.” On page 215 they quite simply state that by 2050 China will have achieved per capita income (not GDP growth) equal to that of the United States in 2011.

Now, China’s population is expected to have started the Development Decline by then and is variously predicted to drop from a high of 1.44 billion in 2030 to about 1.25 billion by 2050.

Americans used about 310 million btus per person per year in 2011. I think it safe to assume that Chinese people with the same income would be both pleased and able to do the same.

That would yield a total of 389 quads just from China alone. In 2050…

As it happens, I think China will persuade itself to go for a lower intensity lifestyle and the global total will be around 3,000 quads by 2075. But if I’m erring, I’m erring on the low side.

And I believe in my Lukewarm heart of hearts that right around 2075 our energy consumption and related emissions will actually begin to take the lead in forcing our climate–somewhat in the way activists are mistakenly describing current weather conditions.

This will have consequences.

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38 responses to “Lukewarming 2075-2100

  1. The fingerprint of “dangerous” AGW is an accelerating temperature trend with BAU carbon output. This is the prediction of the science. What do we do if this trend is not evident over the past 30 years?

    Pretend we never predicted this?

    Claim that natural forces are suppressing this trend (even though we previously stated these forces were insignificant)?

    or revisit our theory?

    The more the same people preaching “science” ignore the data they previously said was important, the more they will be disregarded.

    The reasonable approach is too wait and see, anathema to the greens.

  2. Hi Tom,
    So according to your predictions (would it be too harsh to call them guesses), the real societal benefits of CO2 will have to wait until 2075. Or did I put words in your mouth?

  3. “Yes, I think anthropogenic warming from all sources could plausibly be about 1.5C in the last 25 years of the 21st Century.”

    You could also say that it is plausible that there will be no temperature rise following 2075. There are simply too many possibilities, uncertainties and variables involved to make any meaningful prediction of global temperatures that far out. Would anyone 65 years ago have been able to predict, much less prepare for, our next 25 years?

    As you say, the world is going to demand a huge increase in energy supply by 2075. I’d much rather talk about how to achieve that in a low impact way than to spend time worrying about what might happen if we don’t.

    • You kinda put your finger on the reason I’ve spent the last year writing about this stuff. I’d much rather focus on solutions. But somebody has to admit there’s a problem first. If everybody is planning for about 700 quads of consumption in 2030 and demand is 950, the extra 250 will come from coal. And not clean coal–coal scrounged from any old where and burnt any old how. And then it will get worse.

      • Hi Tom,
        ” And not clean coal–coal scrounged from any old where and burnt any old how. And then it will get worse.”

        Recall, that CO2 lags temperature by 100-800 years, there has been no warming for 16 years, 0.5 degree rise would be beneficial by anyone’s standards. Just what is it that is going to get “worse”.

      • In this case it will be the need of developing countries to use any coal they can find burned anywhere they can light a match.

      • “I’d much rather focus on solutions. But somebody has to admit there’s a problem first. ”
        Not sure I agree. Think of the phrase “It ain’t rocket science.” An amazing amount of science went into the planning to get someone to the moon, but at the end of the day the rocket captured the imagination. We only cared about escape velocity, orbits, and material sciences because they dictated how gigantic the engines would be on the Saturn V. No rockets, no rocket science.
        Calculating 3000quads is less interesting to typical person than discussing what will produce 3000quads. Nobody aspires to a low-energy future (the sustainability movement’s preferred solution), so “efficiency” isn’t the rocket. Nobody believes wind and solar will produce a significant amount of 3000quads, so they aren’t your rockets. Nobody has ever been titillated by an international treaty or a tax plan, so don’t expect it to happen with this issue.
        Climate concern suffers because it won’t accept a plausible rocket, so it gets stuck arguing over what time of day to launch from Cape Canaveral. I think I’ve officially stretched that metaphore as far as it will go :)

      • Well, what’s a meta for, if not for stretching?

  4. Can we imagine looking at our technology 75 years ago, did anyone get it right or even come close? Most predictions were about space travel etc, no-one guessed the digital revolution. Lesson there for guessing future technologies and outcomes? When we base guesses or models and outcomes for a long way into the future based on current knowledge and technology we are invariably wrong, when we say whatever it is, no-one will see it coming, we are invariably correct.

    • Hi Gareth

      To a considerable extent you are correct. We don’t know the impacts of future innovations. However, innovations in energy have almost always taken 50 years to have a significant impact.

      And we are fairly confident about population figures. And we have a decent track record at projecting GDP growth. So, even before we look at innovations we can make a fair stab at looking at demand–energy consumption.

      How that demand is satisfied may well be influenced by innovation. And if that demand is satisfied by renewable energy then impacts on climate will be lessened considerably. But remember this–in 2010 the world used 523 quads of energy. 52 came from renewable sources. Of those 52, 2 came from wind, solar and biofuels. The rest was hydroelectric power. If hydro doubles in the next 50 years, it will be 100 quads. If wind, solar and biofuels quadruple, it will be 8 quads.

  5. Wait. What?

    I always assumed that your 2 C by 2100 was including the 0.8 C seen to date. In this, you are effectively saying 2.8 C above pre-industrial by 2100… which puts you a whole 0.2 C below the mainstream (aka ‘radical alarmist’ in ‘lukewarmer’ speak) ~3 C by 2100 estimates. But the really crazy part is that you’re predicting 1.5 C in just 25 years… which makes you the most extreme alarmist out there so far as I can tell. At that rate we’d be looking at ~9 C (or more) and the extinction of most life on Earth by 2200…. unless you are expecting more ‘magical unexplained shifts’ after 2100.

    • No, CBDunkerson

      I’m expecting that the bulk of the warming will be telescoped into a short period. If that makes me extreme, I guess I’m extreme. I don’t think so, however.

      The reason I’m expecting 2C total is that I include forcings other than CO2.

      I think that due to population stabilization, energy efficiency and saturation of cars/appliances that things stabilize quickly after 2100.

      • I always find it amusing–people on your side of the fence have spent years frantically not paying attention to what I actually write because they’re so convinced I’m a Dreaded Denier (not to be confused with DareDevil, although I do so resemble Ben Affleck and was sighted in public with J-Lo). And then finally the penny drops and they say ‘Wait. What?’ Happened with Neven. Happened with Tobis. Happened with PDA. Happened with a bunch of the crew.

  6. Yes, how could anyone possibly be unclear about your position when you constantly denounce those ‘radical alarmists’ who are predicting pretty much the same warming by 2100 that you are?

    ‘They’re radical alarmists! And I agree with them.’ :]

    • I somehow think most can see the difference.

    • CBD, have you been following the posts by Annon and others. Sensitivity estimates are way down. Nothing to worry about. All the CO2 we pump from here to 2100 will do nothing but good, especially for the underdeveloped countries. Want to feed a hungry child – pump a little CO2 into the air. Alarmists are going to have to find another scare. Can’t wait to see what it is.

      • Bob, the ‘most likely’ fast feedback sensitivity estimate has barely budged (i.e. 3 +/- 0.3 C) over the past 40 years. The only change in that time has been that the best to worst case scenarios around that most likely estimate have continually narrowed. At this point anyone predicting a possible sensitivity lower than 1.5 C or higher than 4.5 C, or using a range that excludes 3 C, is basically clueless.

        But don’t worry ‘skeptics’ and ‘lukewarmers’ will ALWAYS come up with more nonsense to believe.

      • CBD, I see you can’t shed your alarmist proclivities. Think and study a little deeper. You’ll come around.

      • CBD, have you read this :
        “Annan has now written another potentially blockbuster post, which discusses recent publications in the area of detection and attribution (D&A) – the bit of the climate change science that assigns guilt. What Annan reveals is that the studies that have supported the claim of “the majority of recent warming is manmade” are fatally flawed.”

      • Bob, read Annan’s post closely, he’s saying that conventional approaches to D&A will fail despite AGW being real.

        “A moment’s thought should confirm that failure to “attribute” in this sense will be an inevitable consequence of gathering a sufficiently long and precise time series of data…this problem will only get worse as the data will surely keep pouring in at a rate greater than model improvement can keep up.”

        The problem is one of methodology, he’s not claiming that climate theory regarding CO2 forcing and feedbacks are wrong.

      • Also this, from the post:

        “I’ve been fairly critical of the conventional D&A approach in the past, primarily on the grounds that the null hypothesis of no anthropogenic influence is always false a priori (and therefore a failure to detect an anthropogenic influence is always a matter of insufficient data).”

        Think that through …

        Annan’s thinking is very heavily influenced by the fact that he’s a Bayesian statistician who rejects the frequentist statistics traditionally applied to analysis of time series data, of which climate data is an extremely small subset.

        Note that there are many professional statisticians in the world who have no interest in climate data per se that do not fully accept the arguments made about data analysis by Bayesians like Annan.

      • dHogaza, I don’t disagree with any thing you said here. I also stand by what I said because that is exactly what Annan said. So allow me to repeat, ” “Annan has now written another potentially blockbuster post, which discusses recent publications in the area of detection and attribution (D&A) – the bit of the climate change science that assigns guilt. What Annan reveals is that the studies that have supported the claim of “the majority of recent warming is manmade” are fatally flawed.” Annan is one of the best you have on the warm side and you should not try to spin it any other way.

      • dHogaza, since you like to quote Annan, I will give you a few more:

        “James Annan writes on his blog here
        “Interestingly, one of them stated quite openly in a meeting I attended a few years ago that he deliberately lied in these sort of elicitation exercises (i.e. exaggerating the probability of high sensitivity) in order to help motivate political action.”
        As I said to Andy Revkin (and he published on his blog), the additional decade of temperature data from 2000 onwards (even the AR4 estimates typically ignored the post-2000 years) can only work to reduce estimates of sensitivity, and that’s before we even consider the reduction in estimates of negative aerosol forcing, and additional forcing from black carbon (the latter being very new, is not included in any calculations AIUI). It’s increasingly difficult to reconcile a high climate sensitivity (say over 4C) with the observational evidence for the planetary energy balance over the industrial era.

        “Since the IPCC can no longer defend their old analyses in any meaningful manner, it seems they have to resort to an unsupported “this is what we think, because we asked our pals”. It’s essentially the Lindzen strategy in reverse: having firmly wedded themselves to their politically convenient long tail of high values, their response to new evidence is little more than sticking their fingers in their ears and singing “la la la I can’t hear you”.

        “. Interestingly, one of them stated quite openly in a meeting I attended a few years ago that he deliberately lied in these sort of elicitation exercises (i.e. exaggerating the probability of high sensitivity) in order to help motivate political action. Of course, there may be others who lie in the other direction, which is why it seems bizarre that the IPCC appeared to rely so heavily on this paper to justify their choice, rather than relying on published quantitative analyses of observational data.”

  7. Tom,
    Your sincerity in this long disupte is quite clear. However I would ask you to comment on your premise a bit: why do you save the vast majority of your projected scenario for out past 2075? It is convenient to make one’s prophecies for a time sufficiently far in the future so as to avoid being around when they come due. If past is prologue, the warming in late 21st century will be needed to get things back to about where they are now, in recovery from the mid-century cooling. Also, I would ask you to consider that the acceptance of graphs that utlize axis metrics which exaggerate the amount of change is to accept distortion as a premise.

    • Hi Hunter

      For your first question, that’s just the way the numbers came out for me. When do you think the current temperature stall will finish, if ever?

      And what makes you think I won’t be around to see them come true? Don’t you have your copy of ‘The Singularity is Near’ well, near?

  8. Tom, your analysis of future energy needs is defensible and quite reasonable. However, I do question your assumption that the bulk of the increase must come from coal. For the next 50 years at least I see gas as having a strong advantage over coal, even without carbon taxes. With carbon taxes (and I note that China is now planning one) it is a no brainer. The carbon intensity of future energy generation is therefore much less than current energy generation.
    This does not even take account of the arguments of people such as Dave Rutledge who argue that peak coal is almost upon us. Nor the possibility that nuclear will become more acceptable and more affordable due to removal of planning impediments. I notice that Russia is planning on generating 75% of its electricity from nuclear by 2075.

    • Hi Alex

      Well it isn’t written in stone that coal is the default option. But I’ll bet it ends up that way for a variety of reasons.

      First, it’s the one you can grab onto quickest. If you’re short of fuel it is often lying on top of the ground in developing countries, or at least can be mined easily.

      Second, fracked gas–assuming it’s available in high quantity at a low price–will quite possibly trigger an explosion (sorry…) in its use for vehicle transportation. And that will probably be more profitable.

      I think nuke actually will save the day towards the end of the century, which is why I’m not overly alarmed. But it’s just going to take a long time to get it to scale–training people, getting volume production of the modules. It just won’t happen overnight.

      • Average coal mine depth in China is 550 meters. I think if you delve into developing countries you might discover a reason they haven’t developed is a lack of inexpensively exploitable coal.

        Mining coal in China is an order of magnitude more difficult then Wyoming

      • Millions of poor Chinese take a wheelbarrow up nearby mountains and hillsides to dig a 10-foot hole in the ground and grab their weeek’s coal, which they burn in a coal-fired stove in their living room.

      • “Millions in China digging 10 foot holes and getting coal’

        Residential consumption is the only sector where coal has a shrinking market. Coal consumption in this sector peaked at 175 Million tons in 1988 and has experienced constant decline since then.

        Humanity is basically lazy…we’ll burn whatever is easiest first…and then when that isn’t so easy any more we switch to something else.

        Resdential coal consumption in China has been declining for 25 years…just as it declined in the rest of the world. China was exporting coal in 2002 at $22/tonne…today it imports at $100/tonne.

        The easy to extract, near population center coal in China has been burned…it is gone…never to return.

  9. Tom, according to the EIA’s #’s, world consumption was 488 QBTU in 2009. Where does the 523 in 2010 come from? The 488-523 jump in one year (7.26%) would be the biggest year over year growth since 1980 by far (next biggest 5.4%, 83-84; 4.2% 03-04). Using EIA’s #s 1980-2009, try calculating running 10yr compound annual growth rates. You’ll find two peaks: 1991, 2.4%; 2006, 2.64%. Each was followed by solid declines that cut the 10yr CAGR by 40%.

    So I guess I’m suggesting the 523 in 2010 number seems way, way out of place in that series. After all, most of the world is still struggling through the wake of the financial crisis here in 2013. And yes, China is still growing, but not at the pace it was growing in 2005-2008, while the US energy use is declining by EIA #’s through 2011.

    Your 3000 QBTU between now (that is, 523 QBTU in 2010) and 2075 requires a steady growth rate of 2.72%/yr. – higher than the most recent peaks in the 10yr average. Meanwhile, US energy consumption growth, according to the 2012 energy report (EIA), averaged only 1.38% between 1983 and 2007. And I cherry-picked those numbers to represent the widest possible spread – a valley to peak comparison, if you will. Also, by EIA’s #s, US annual growth 1949-2011 was 1.81%.

    I’m not sure how all that will (or won’t) fit into your thinking.

    • Hi Jimmy

      I go off this table:

      And it looks like they adjusted it down one quad, from 523 to 522 in 2010. They do that occasionally.

      That table is really useful if you are going to dive into it.

      My worry about energy does not involve the U.S. or even the OECD. It’s all about the developing world…

      • Hi Tom,

        Thanks for providing the link.

        I believe the table you referenced is a model case. The table’s date is March 2011, only 3 months after the end of 2010 – too soon for hard data on 2010, I think – so I suspect the 2010 data is model data.

        The EIA has hard data here, probably also subject to revision, through 2010. The current value for 2010 is: 510.551 QBTU. Here’s the source:

        The value of ~511 QBtu for 2010 is more in line with historical annual growth rates. Thus, the growth from 2009 to 2010 becomes 4.71% – second highest since 1980 and about 15% below the highest value – rather than 7.26%, the highest value by far.

        I realize your interested in world energy consumption growth rates, but I pointed out the US growth rate because the US was the most rapidly growing economy over the period 1949-2011. It gives us a very rough upper constraint on how fast an economy’s consumption can grow over the longer term.

        For the full period of the table referenced above (1949-2010), the annual growth rate for energy consumption was 1.98%. OTOH, going from 511 to 3000 QBtu from 2010 to 2075 requires a growth rate of 2.76%, about 40% higher than the historical growth rate, sustained over 65 years.

        Energy consumption grew at 2.68% CAGR (compounded annual growth rate) from 2001-2010, just slightly below the value your numbers require. But that’s during a massive economic expansion in China and India. Year over year growth tells a different story – it fell every year after peaking in 2005, until the big jump in 2010. I suspect 2010′s big jump will be followed by something much smaller: US consumption has fallen every year since 2008, and Europe can’t be doing much better.

        Overall, my bets are for a world energy consumption growth rate that’s within a dime or so of the long term average for the past 60 years: about 2%.

      • Hi Jimmy, well that’s what all the big guys think as well, so if you’re right you’re in good company. I know I’m an outlier.

        But China doubled its energy consumption between 2000 and 2010. And it is their stated policy to do so again by 2020. And they’re on track to do it. Do you think they’ll stop there?

  10. Tom,

    I recently came across a post on energy efficiency and the rebound effect. Thought you might like it for your files- especially this part-

    “Do the International Energy Agency or Intergovernmental Panel on Climate Change understand rebound?-
    The vast majority of energy modelers whose work feeds into IPCC and IEA reports are using models that are fundamentally limited in several ways. Even the best among these models use oversimplified and arbitrary functional forms, assume (rather than measure) key parameter values, ignore non-energy efficiency gains, and don’t introduce energy efficiency in any properly defensible way.

    I eagerly await the day when energy consumption forecasters pay closer attention to basic microeconomic principles, sensibly link engineering efficiency gains to real-world economic decision making, undertake proper econometric measurements of the key driving parameters, and squarely address energy efficiency rebound in a way that gives policy makers what they sorely need.”

    • Hi Kakatoa

      I intend to do a series on the work of Stanley Jevons, the Kaya identity, energy ladder and more, and will be talking about the rebound effect at length.

      I know the rebound effect exists. My counter to their arguments is that the concept was developed without more than a glance at the equally valid concept of saturation. My stereotype example is that you might save enough money on gas to buy another car, but you can only drive one at a time. (Not a perfect example as many will buy an extra car for their spouse/kids… but you see what I mean. If you have a light plugged into every receptacle in your house, you still cannot leave them carelessly switched on for more than 24 hours a day.)

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