Cassandra has moved. Ugo Bardi publishes now on a new site called "The Seneca Effect."

Sunday, March 6, 2016

Living in interesting times: have CO2 emissions peaked?

Image from MIT Technology Review

The projections that had been circulating during the past few months turned out to be correct. Now, it is official: the global carbon dioxide (CO2) emissions peaked in 2014 and went down in 2015. And this could be a momentous change.

Don't expect the emission peak, alone, to save us from the impending climate disaster, but, if CO2 emissions will start an irreversible decline, then we need to rethink several assumptions that we have been making on how to deal with climate change. In particular, depletion is normally assumed to be a minor factor in determining the trajectory of the world's economy during the coming decades, but that may not be the case. Depletion is not a good thing in itself, but it might help us (perhaps) to stay within the "safe" limits and avoid a climate disaster.

CO2 emissions are mainly the result of the combustion of fossil fuels and of activities made possible by the combustion of fossil fuels. And, since we expect the production of fossil fuels to peak and decline as the result of depletion, it shouldn't be a surprise that CO2 emissions should peak too. But it is surprising that we may be already seeing the peak. For instance, Laherrere had assumed the peak for all fossils to occur not before around 2025. And many people would have seen these projections as ridiculously catastrophistic. Most of the published scenarios for the future saw CO2 emissions increasing for at least a few decades in the future unless draconian economic or legislative measures to limit them were taken.

So, what we are seeing may be simply a fluctuation; not necessarily "the peak". But, it might also be the big one: the point of no-return. From now on, we may find ourselves rolling down on the other side of the Hubbert curve. It would be the true vindication of the "base case" scenario of "The Limits to Growth" that had seen the combination of gradual depletion and pollution to cause the start of the terminal decline of the fossil based industrial system at some moment during the 2nd-3rd decade of the 21st century.

Let's assume that we really are at the peak of both emissions and fossil energy consumption, then what? First of all, the event will be surely misinterpreted. The techno-optimists will say that what we are seeing is proof of how human ingenuity can solve all problems while the anti-science crowd will hail these results as the evidence of two things: 1) that climate is nothing to be worried about and 2) that those silly climate scientists have been proven wrong one more time.

Of course, none of these interpretations is correct and the situation remains critical for various good reasons. I can list at least three of them

1. There is really no reason to congratulate ourselves for being so smart. The reduction in emissions may be partly due to better efficiency, renewable energy, and the like. But, mainly, it is the result of the global economic slowdown. The IMF data indicate that the world's GDP has peaked in 2014, together with CO2 emissions and 2016 could shrink even more (see also Tyler Durden). The reasons for all this have to do with the gradual decline of the energy yield of fossil fuels, in turn related to progressive depletion. That has generated the disaster that struck the oil industry and the whole mineral industry in the form of collapsing prices. With the decline of the extractive industry, the reason why emissions peaked is because people are poorer, not smarter (so much for the so-called "dematerialization" of the economy).

2. The fact that emissions may have peaked does not mean a reduction in the CO2 accumulation in the ecosystem. We are only slowing down the flow, but the stocks keep being filled. CO2 accumulates in two main reservoirs: the atmosphere and the oceans and we may already have too much of it in both. And that says nothing about possible feedback effects out of human control, such as the release of methane from hydrates. So, we are still risking a lot in terms of the very unpleasant things that could occur in the future (including a runaway climate change).

3. Even assuming that emissions are facing an irreversible decline, the decline rate is likely to be still too slow to stay within the limits that are perceived as (perhaps) safe. Let's assume that emissions will follow a "Hubbert" curve, that is they will go down at the same speed as they went up so far. It means that in the future we will emit approximately as much we have emitted up to now. Can that save us from catastrophic climate change? Not really. So far, we emitted a grand total 1465 gigaton (Gt) of CO2) that might be the amount that we'll emit in the future. Unfortunately, according to Meinshausen et al  in order to have a 25% probability to stay below the 2 degrees limit, we cannot emit more than about 1000 Gt of CO2. And we are not there. According to Meisenhausen, with 1500 Gt of CO2 emitted, we are almost exactly at a 50/50 probability of staying below 2 C. If your hobby is to play the Russian roulette with a real gun, you should enjoy the situation we find ourselves in.

Still, the possible peaking of the CO2 emission. although not sufficient to save us, may not be a bad thing since, at least, it eases the task of staying within the safe limits. And not just that. These new data should lead us to rethink about some of our entrenched assumptions. So far, we have been assuming that a herculean effort will be needed to force the economic system to stop using resources that were assumed to be abundant and cheap. So herculean that it seemed to be totally impossible. But, if we really are at the peak of fossils, then the effort needed could be much less herculean: depletion will help us a lot. At this point, the emphasis should shift from "phasing out" fossil fuels - that would go largely by itself - to "phasing in" renewables - that needs a specific effort. And if we want to phase in the renewables we need to do that before the collapse of the fossil fuel industry makes it impossible to invest enough in their deployment.

Finally, there is another interesting possibility (in the sense of the ancient Chinese curse: 'may you live in interesting times'). The decline might not follow a
Hubbert curve but, rather, a Seneca curve. That is, emissions may decline much faster than they grew in the past. That implies, of course, a parallel crash of fossil fuel production and of the world GDP. The resulting  economic collapse might keep us within the "safe" climate limits. That would be so bad to be almost unimaginable, but, at least, better than some truly horrible climate scenarios. And, why not, we could have both the collapse of the economy and a runaway climate change! (not just fire or ice, but fire and ice)

Truly, we live in interesting times.


Note: from some messages I received, it seems that many people find that the mere concept that the world GDP could decline is unthinkable and contrary to some universal principle. And, yet, it is shrinking. See this plot from Vox.


  1. This is the problem with all his hype on CO2 and climate change. The climate is a complex system and will not return to its previous state (say that of 50 or 100 years ago) just because CO2 stop increasing.
    On the other hand Aleklett his group already showed that several IPCC scenario were not realistic because based on far too optimistic availability of fossils fuels:
    The decline of the industrial civilization will take take care of the CO2, for what this matters. The problem has been always energy, rather than climate of which we humans only accelerate its constante change...

  2. This may be good news, and China may be installing renewable power and cutting fossil power at an amazing rate. But short term stats and figures out of China are deeply suspect. Both on GDP growth and on energy supply and type. The one sure way we'd know if CO2 emissions really have peaked is a change in the rate of growth in CO2 concentration in the atmosphere.

    And that's the problem. No matter what stories we tell ourselves, the CO2 concentration is still growing. And even though the output may be flat or starting to reduce it's also at a higher rate than it's ever been.

    1. Yes ... it is a dynamic situation ...
      Recent Monthly Average Mauna Loa CO2
      January 2016: 402.52 ppm
      January 2015: 399.96 ppm

      We presumably will not reach 'Peak CO2' atmosphere until rate of CO2 emission declines to match the rate of sequestration. Sequestration rate currently is at about 40% of the annual emission rate. Climate forcing (concentration of non-condensing GHG) from anthropic emission will remain higher than current concentration (+400ppm) presumably for centuries to come, even as future CO2 atmospheric levels decline from their future peak.

      Methane has recently increased again apparently mainly because of LTO & fracked methane wells in the USA.


  3. It's a mix of things. Some is efficiency. Some ir renewable (see China) although small yet. And yes, some is less consumption, that if it's superfluous consumption means savings, but if it's basic needs means poverty.

    A massive deployment of renewable energy remains as a possibility yet, so I didn't discard this way so fast.

  4. If the world hopes to avoid the most catastrophic effects of climate change, humanity must emit less than half the carbon dioxide than previously thought in the coming years, a new study shows.

    1. Today could be seen as a bad joke, but it's possible that in the future, past the mid of the century, we pay for negative emissions.

      Move machines to grow forest to bury wood using only electricity from renewable sources.

  5. I wonder if this carbon peak is true at all. After all, oil production has increased form 75 to 78 million barrels a day in 2015, while coal production increased by 1,9%. Therefore one has to wonder where that alleged decrease comes from and the figures from Mauna Loa seem to indicate that CO2 accumulation is not slowing down.

    1. As far as I understand, the data on emissions are based on what is actually burned. But that is not the same of what is produced (extracted). So, it is likely that the peaking reflects the storage of fuels that are extracted, but not burned. That's, by the way, the reason of the price collapse

    2. Yes, the latest Mauna Loa figures have CO2 concentration increasing, year on year, at the fastest rate on record. That implies that CO2 emissions did not actually decline in 2015. I think the estimates need to be questioned though I don't think the final estimate for 2015 will be out until much later in the year.

      It may be that we are burning dirtier stuff now, which can increase emissions even if less is burned. But the simplest explanation for any decrease is a contracting world economy. Maybe emissions estimates are a better measure of the world economy than official GDP figures!

  6. I'm more and more convinced that the next 10/15 years will be crucial for humankind destiny. We have now optimal conditions to sustain a gigantic deployment of renewables, thanks to 1) low oil price, 2) adequate availability of fossil fuels, 3) relative macroeconomic stability. Postponing such an effort might ultimately be fatal if climate change will undergo an acceleration, as it seems now to be true. Unfortunately, the timelines of the Paris Agreement conflict with the need of an urgent action.

  7. That paper you linked to, about the carbon budget, was from 2009 and the 1000 Gt CO2 budget (for a 25% chance of exceeding 2C) was for the period from 2000. What must the budget be now, after another 16 years of increasing emissions? Certainly a lot lower, maybe half.

  8. One estimate from Frank Landis - Hot Earth Dreams is that there is roughly 1 GtC of easily accessible fossil fuel left. And we'll burn through that and chuck it into the atmosphere in one last #terafart. The only question is how long. It could be 50 years or it could be 200. But this century is most likely.

  9. BS! Atmospheric co2 jumped actually something like 4 parts / million in 2015 and also in 2014 and every years before that .There is no decline in co2 there is a constant rise This guy has no clue . He is only speaking of co2 output data submitted by countries respecting economic activities and they all lie about their co2 output china and india the most actually the chinese do lie and the indians just don`t give a C`mon what a kaka

  10. Actually, it could turn out it is a far worst news than that. CO2 is not the sole greenhouse gas, with CO2 there is CH4, NO2, CFCs, HCFCs, etc... But there is also aerosols which tend to cool down the earth. The negative forcing of aerosols is approximately equal to the forcing of all the greenhouse gases, excepted CO2 (around 1 or 1.5 W/m² of forcing). A common (explicit or implicit) assumption is to neglect others greenhouse gases on this ground. But, if emissions of greenhouse gases decrease, emissions of aerosols is set to decrease also. And aerosols have a short residence time in the atmosphere (around 7 - 8 weeks approximately in troposphere, a bit more if they can reach stratosphere like with erupting volcanoes) while greenhouse gases have a very long resident time. The sole exception here is CH4, wich has a resident time of about 10 years. All others greenhouse gases are bound to stay hundreds or even thousands years. The forcing of the sum of the greenhouse gases is already sufficient to bring around 2°C of warming. And the most probable is that in the end we will see the realization of this warming. And even for the 1.5°C, looking only at CO2, there is already nearly all the CO2 needed to overshoot this target -only a few years remaining before the exhaustion of the budget in the most optimistic case-. Even more “funny”, carbon cycle feedback will be reinforced by the non-CO2 forcing (like the melting of the permafrost), with the distinct possibility CO2 will continue to build up event after humans cease to emit carbon...

    People tend to have difficulties to grasp two points with the climate. Climate system has a huge inertia and even if mean temperature has not yet reached 1.5°C (this threshold was at times crossed this year but it is not yet a new mean, currently the climate is running about 1°C hotter than the preindustrial climate), we are already committed to cross this value in the near term. It's no longer possible to talk about the 1.5°C target. And secondly, in the end the industrial civilization will collapse and common, “rosy” assumptions (like neglecting CH4, NO2, etc... on the ground of the negative aerosols) are no more than rosy assumptions which will never be checked.

    And, for this part it is my own opinion, it is quite possible I think we are already seeing the start of the warming due to the decrease in aerosols load. Perhaps I am wrong, but when compared with others big El Nino, temperatures seems to be raising a bit more than expected (for people knowing a bit about this subject, global temperatures warm about 0.07°C with one unit of MEI : and currently we are more around 0.1 or 0.15° of warming with one unit of MEI. Still not significant and perhaps it is not nothing, but I think it is worth monitoring this point).

  11. I think these figures come from the IEA and are about to "energy related CO2 emissions" and primarily about electricity production. While that's probably dominant, It's not clear to me what proportion this is of total CO2 emissions and what the other sources might have done. The original PR (along with the other blogs and news outlets reporting it) is less than clear about this.

  12. To put it mildly, it's pure bullshit actually when you dig a bit into the figures. The general trend is here but in the details it's not credible -but it's the same for about every thing of the IEA, if you don't look to closely it's OK but if you start to think 1 minute about it...-. There is 2 others sources of information, CDIAC & BP:

    According to the sources, CO2 emissions increase from fossil fuels by 0.5% from 2013 to 2014, and according to CDIAC a decrease of 0.6% from 2014 to 2015. For BP, we will have to wait until May & the release of its next statistical review.

    For CO2, 1 Gt CO2 is 0.273 Gt C (CDIAC actually count in Gt C). There is about 9 Gt of emissions from fossils fuels (45% for coal, 35% for oil and 20% for gas). There is about 0.5 Gt C from cement production. And there is about 1 to 2 Gt C from "land use change" -deforestation-. CDIAC reports also land use change and cement. From 2013 to 2014, fossil fuels and cement production combined increased 0.6% (a bit more than the 0.5% from fossil fuels only due to an increase from cement production). Land use change are the real nightmare of the emissions side of C cycle. For 2013 and 2014, it is in the neighborhood of 1 Gt C, but an exact value is almost impossible to pin down. For the figures, CDIAC comes with 0.92 Gt C in 2013 and 1.02 Gt C in 2014. For 2015, I don't know, but a notable increase seems probable.

    IEA data are probably (I'm not promoting conspiracy theories but the inaccuracy of IEA data is worth a lorry and it's collusion with politic power too...) "rounded" to give the rosier picture possible.
    IEA claims an increase of 0.2% in 2014, which allow IEA to pretend that CO2 emissions have in some way "decoupled" with economic growth. But an increase of only 0.2% from 2013 to 2014 is impossible. Oil consumption (and so CO2 emissions coming from oil) increased 0.8% about, and oil is not traded over the counter. Up to 90% to 95% are sold under term contracts, and you only have to sum up term contracts. I can't see any way oil could not have increased 0.8% in 2014 (there is still the possibility that IEA is not able to count up to 10, given its extraordinarily poor record...). For gas & coal it's a bit more difficult, but BP & CDIAC come with 0.4% increase for both, which give confidence in their estimations. Nevertheless, given the fact that mix ratio is known (about 45 – 35 – 20 % ) and assuming 1 of the 2 unknowns follows the value of BP / CDIAC, you have the following. For a 0.2% of CO2 increase only, you have to decrease coal consumption by 0.4% or a decrease of 1.4% (!) of gas consumption. Perhaps the IEA has found the philosopher's stone and is able to make coal or gas to disappear. It seems impossible to explain how such a large, worldwide decrease of gas and/or coal consumption could have been missed. Moreover, about every government was pushing forward for the gas in 2014 saying it's a bridge to renewables, and prices where still high, and USA were still frenetically fracking, and... A decrease in gas consumption in 2014 seems totally weird. Perhaps coal so, but missing a 0.4% worldwide decrease, even with the uncertainties acknowledges, is pretty unrealistic.

    IEA is an entity of the OECD, and it us the answer of the oil consumers to the OPEC. So logicaly IEA is trying to promote the interest of the OECD. With the current peak oil and the summit of Paris, IEA is desperately trying to transform the dream of a green, energy autonomous economy into hard reality. As sais, in 2014 IEA start to speak about a decoupling. And now that emissions start to decrease, IEA is advancing this idea with more pugnacity. But to do this, IEA says that economy grows in 2015, which is blatantly false. It's the job of IEA to sell a rosy (or now a “greeny”) future and so IEA will remain the most unreliable source of information

  13. j'ai retrouvé l'humus que les industriels ont fait disparaître de la culture pour produire des engrais chimique qui ont apporté la mort des sols les maladies des humains j'ai un site merci lombrics et je suis entrain d'en écrire un autre sur le recyclage de la nature



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)