Has Global CO2 peaked?

SUBHEAD: Now, it is official. Global CO2 emissions peaked in 2014 and are down in 2015.

By Ugo Bardi on 6 March 2016 for Cassandra's Legacy  -
(http://cassandralegacy.blogspot.com/2016/03/an-epochal-change-have-co2-emissions.html)


Image above: Detail of chart showing global CO2 emmissions history. Click for full image. From original article and (https://www.technologyreview.com/s/600871/have-global-co2-emissions-peaked/).

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.
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