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

Tuesday, May 8, 2018

Negative Emission Technologies: maybe we can still save the world, after all!

The ancient Egyptians knew how to manage the commons. A single central authority managed the Nile river, to make sure that everybody had enough water for their needs. Could we do the same for our atmospheric commons and save the world by using negative emission technologies (NET)? Above, a Pharaoh (probably Ramses II) receives the crown of Upper and Lower Egypt.

Before I went to hear Klaus Lackner in Les Houches in March 2018 (image on the right), I had a very poor opinion of direct atmospheric capture (DAC) and negative emission technologies (NET).  If you had asked me, I would have said that there is no need for these technologies: why can't we just avoid emissions, instead? And if you were to tell me about "artificial trees," I would have told you that Mother Nature spent some 350 million years to develop trees, and She knows better than us how to remove CO2 from the air.

Well, I changed my mind. I came out of Lackner's seminar convinced that DAC/NET may give us a fighting chance to survive. Consider that it is perfectly possible that we already passed the "tipping point" that will lead Earth's climate to move to a different climate state. In that case, reducing emissions or even zeroing them will not help us. And, in any case, we are not doing that fast enough. So, DAC/NET as the last hope to save civilization? (*) Possible, yes, of course not really likely given the situation but, who knows? Let me explain.

First of all, let me state a point that is clear to me: the energy transition is NOT a technological problem. We could go through the transition fast enough to avoid running out of energy and before climate change destroys us. But only if we were willing to invest enough in the transition, and we aren't.

So, the problem is really financial and political. And, at present, it seems to be impossible to solve since the idea that civilization (and perhaps humankind) is at risk is just not penetrating into the consciousness of the decision-makers.

The main problem is that we haven't been able to find a way to frame the message in the right way. Let's imagine a dialog between a scientist and the public.

Scientist: We have a big problem with CO2 emissions. The atmosphere is going to overheat, the tropics will be desertified, the sea level will rise and swamp all the coastal cities, lots of people will die of starvation. And more dark and dire things. 

Public. Ouch, that's terrible. What can we do to avoid that? 

Scientist. Well, you have to change your lifestyle. Give up your car for a bicycle, turn down your thermostat, no vacations overseas, that kind of things. 

Public. I see...  Mr. Scientist, but are YOU doing that?

Scientist: Well, I do what I can but, you see, there is this thing that we scientists call the "h-factor" and the higher it is, the higher our salary is, so I have to attend international conferences, take planes, travel, all that. . .

Public. You know, Mr. Scientist, I think you are part of a conspiracy of scientists who invented the idea of global warming in order to siphon money out of the pockets of taxpayers. And, by the way, on the next elections, I am going to vote for someone who will defund your research so that you'll stop bothering me with this scam.

See the problem? Instead, let's imagine that the last part of the dialog goes in a different way

Scientist. A little CO2 in the atmosphere is a good thing, but too much of it becomes a waste problem which may create a climate disaster.

Public. So, Mr. Scientist, what do we have to do to avoid that? 

Scientist. Well, we have ways to remove the excess CO2 in the atmosphere. It will cost you some money, of course, but it is just like for the household waste you produce. Every good citizen has to pay to have their waste taken care of. 

Public. But what are YOU doing about that?

Scientist: Me? Of course, I am going to pay for the removal of my CO2 waste, just like everybody else. 

Public. Hmmm...... I see. How much that would cost?

So, the idea of atmospheric CO2 removal - NET - could be just the kind of message that goes through and that can be understood by almost everybody. Lackner himself confirms that from his experience in Arizona, where he works. Arizona is not known to be a place where people agree with the idea that AGW exists and is a problem. But Lackner reports that when the climate problem is framed in terms of "clean up your mess," then even the most hardened science disbelievers may grudgingly admit that something needs to be done. And to the people who insist that "CO2 is not a pollutant" you can just answer, "nor is coffee, but if you spill some of it on your carpet you'll want to remove it."

Of course, a good message is useless if applied to a technology that can't work but, in this case, I think there are reasons to think that DAC/NET could. It is a complex story, but you can start looking at it from Lackner's papers at this link. You can also find useful data about costs and about the energy involved at this link. For something not academic, see this article on The Guardian.

You'll see that this technology is a thoroughly studied subject, not an idea just thrown in. And it has a number of advantages. One is that it is much more effective than the IPCC idea of BECCS (bioenergy and carbon capture and sequestration) since DAC plants need no water or fertilizers and they can be placed anywhere, even in the middle of a desert. Then, DAC machines are flexible: the CO2 removed from the atmosphere can be sequestered underground but also, if needed, used to produce fuels and chemicals: you can "tune" the removal without having to leave the machines idle.

A rough estimate of the energy involved in the DAC task says that about 10 GW of continuous power would be required in order to remove one billion tons of CO2 per year. Since we are emitting some 38 Gtons of CO2 per year, the energy needed for DAC is large, some 500 GW per year of continuous power. But the world consumes today about 15 TW of power, so it is not unreasonably large. Of course, it has to be RENEWABLE energy, otherwise it would make no sense. Using fossil fuels to remove CO2 from the atmosphere would be self-defeating. So, the effort would consume most or all the renewable energy we are producing nowadays: we would have to step up production of at least one order of magnitude, probably more than one. But it is not impossible.

But don't think of NET as a way to keep burning more and more fossil fuels. It is an emergency tool to remedy the damage we have already done: if we keep at doing more damage, then it will be useless. It needs to be coupled with a rapid reduction in emissions and the deploying of renewable energy sources. Note also that the amount of CO2 that can be stored underground is not infinite.

Then, it becomes a question of cost and time. We need to build millions of DAC machines in a few decades if we want to control the CO2 concentration in the atmosphere and bring it to levels that we judge safe. Impossible? No: during the second world war, the world managed to produce some five million tanks and military vehicles in about 5 years. In fifty years, a much larger economy such as the present one could well produce tens of millions of DAC machines, also considering that one of these machines is probably less complex and less expensive than a battle tank (to say nothing about being much more useful).

In the end, the essential point of this technology is that it is truly global: DAC machines can be placed anywhere in the world and their effects will be global. As a consequence, operating them requires a global governance system. The situation is not different from that of the ancient Egyptians who needed to manage the Nile in order to ensure that there was enough water for irrigation. They succeeded, so why can't we? It is a great occasion for humankind to get together for a worthy task: managing the atmosphere as a global commons.

Below, King Scorpion II engaged in digging an irrigation ditch in ancient Egypt, in other words, managing the commons!

(*) Note that DAC/NET is absolutely not the same thing as "CCS" (carbon capture and sequestration) intended as a retrofit for existing and new coal plants. Coupling coal with CCS is just an expensive way to keep going with obsolete technologies and will do more damage than good if it is deployed.


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)