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.

The climate emergency: time to switch to panic mode?

The latest temperature data have broken all records (image from "think progress"). At best, this is an especially large oscillation and the climate system will be soon back on track; following the predictions of the models - maybe to be retouched to take into account a higher climate sensitivity to CO2 concentrationsing temperatures. At worst, it is an indication that the system is going out of control and moving to a new climate state faster than anyone could have imagined.

James Schlesinger once uttered one of those profound truths that explain a lot of what we see around us: it was: "people have only two modes of operation: complacency and panic."

So far, we have been in the "complacency" mode of operation in regard to climate change: it doesn't exist, if exist it is not a problem, if it is a problem, it is not our fault, and anyway doing something about it would be too expensive to be worth doing. But the latest temperature data are nothing but spine-chilling. What are we seeing? Is this just a sort of a rebound from the so-called "pause"? Or something much more worrisome? We may be seeing something that portends a major switch in the climate system; an unexpected acceleration of the rate of change. There are reasons to be worried, very worried: the CO2 emissions seem to have peaked, but that didn't generate a slowdown of the rate of increase of the CO2 concentration in the atmosphere. If nothing else, it is growing faster than ever. And then there is the ongoing methane spike and, as you know, methane is a much more potent greenhouse gas than CO2.

What's happening? Nobody can say for sure, but these are not good symptoms; not at all. And that may be a good reason to switch to panic mode.

The problem is that societies; specifically in the form called "states" do not normally show much intelligence in their behavior, especially when they are in a state of panic. One of the reasons is that states are normally ruled by psychopaths whose attitude is based on a set of simple rules, mainly involving intimidation or violence, or both. But it is not just a question of psychopaths in power; the whole society reacts to threats like a psychopath: with the emphasis on doing "something", without much concern about whether it is the right thing to do and what would the consequences could be. So, if climate starts to be perceived as a real and immediate threat, we may expect a reaction endowed with all the strategic finesse of a street brawl: "you hit me - I hit you."

A possible, counterintuitive, panic reaction might be of "doubling down" in the denial of the threat. That could lead to actions such as actively suppressing the diffusion of data and studies about climate; de-funding climate research, closing down climate research centers, marginalizing those who believe that climate is a problem; for instance classifying them among "terrorists." All that is already happening in some degree and it may well become the next craze, in particular if the coming US elections will handle the presidency to an active climate denier. That would mean hard times for at least a few years for everyone who is trying to do something against climate change. And, perhaps, it would mean the total ruin of the Earth's ecosystem.

The other possibility is to switch all the way to the other extreme and fight climate change with the same methods used to fight terrorism; that is, bombing it into submission. Of course, you cannot bomb the earth's climate into submission, but the idea of forcing the ecosystem to behave the way we want is the basic concept of "geoengineering".

In the world of environmentalism, geoengineering enjoys more or less the same reputation that Saddam Hussein enjoyed in the Western press in the 1990s. That's for good reasons: geoengineering is often a set of ideas that go from the dangerous to the impossible, all ringing of desperation. For a good idea of how exactly desperate these ideas can be, just take a look at the results of a recent study on the idea of pumping huge amounts of seawater on top of the Antarctic ice sheet in order to prevent sea level rise. If it were a science fiction novel, you'd say it is too silly to be worth reading.

However, it may be appropriate to start familiarizing with the idea that geoengineering might be the next world craze. And, perhaps, it is better to take the risk of doing something that could go wrong than to do nothing, considering that we have been doing nothing so far. Don't forget that there are also good forms of geoengineering, for instance the form called "biosphere regeneration." It is based on reforestation, fighting desertification, regenerative agriculture and the like. Removing some CO2 from the atmosphere by transforming it into plants can't do too much damage, although it cannot be enough to solve the problem. But it may stimulate also other fields of action against climate change; from adaptation to switching to renewable energy. Maybe there is still hope..... maybe.