We need to talk about a geo-intervention

There was a time to work on (the technologies for) reducing emissions of greenhouse gasses (mitigation), now is the time we also need to work on adaptation and now is the time we need to start having a serious conversation about a geo-intervention. The journalistic hook is a new interesting commentary in the scientific journal Nature. It makes the surprising, at least for me, case that a geo-intervention to reduce the insolation will also reduce greenhouse gas concentrations and ocean acidification.

Geo-intervention is the more accurate term for what is commonly called geo-engineering. We cannot engineer the climate, but we may be able to make the climate crisis less harmful. Also our emissions of greenhouse gases are a geo-intervention and by now we cannot even say anymore that it is an unintended intervention. We know what we are doing and are doing it anyway.

The best known geo-intervention is called Solar Radiation Management, that is, a reduction of the amount of sun that is absorbed at the Earth’s surface. This is possible by making the Earth brighter, especially the dark oceans, it may be possible to make clouds brighter or we could install mirrors in space. The most considered Solar Radiation Management method is creating large amounts particles high up in the air in the stratosphere. We know this works, large tropical volcanoes cool the Earth by emitting sulphur dioxide creating small particles in the stratosphere.

Advantages of Solar Radiation Management would be that it is relatively cheap. A medium sized economy like The Netherlands would have to spend a few percent of its gross domestic product to keep the global mean temperature stable. That sounds like a much better deal than having your culture disappear in the waves and more countries will likely be willing to chip in and join such a coalition of the chilling.

The Nature comment makes the interesting case that reducing the warming, will also reduce the concentrations of carbon dioxide in the atmosphere. It would do so as vegetation would take up more carbon dioxide if they are less stressed by the heat. The Arctic would warm less, which would reduce emissions from thawing permafrost. And also humans tend to use less energy when the planet is colder (for example, less air conditioning). Compared to other methods to remove carbon dioxide from the atmosphere solar radiation management is cheap.



Disadvantages are that this would hurt the ozone layer in the stratosphere. Volcanoes use sulphuric dioxide for their Solar Radiation Management, this would make acid rain worse. However, there is ongoing research on alternative particles and hopefully acid rain becomes better anyway due to the energy transition away from burning fossil fuels, which emits sulphuric dioxide in the troposphere where we live. In the dry stratosphere the particles are not removed as fast (for example due to precipitation) as in the troposphere. So we would need much less sulphuric dioxide emissions to cool the planet in the stratosphere than in the troposphere.

Solar Radiation Management can also not stop all climatic changes. Global warming due to greenhouse gases will mostly warm the Arctic (polar amplification), while solar radiation management would mostly cool the tropics where the sun is the strongest. Thus the temperature difference between equator and pole would become smaller and the circulation and water cycle would still change (although probably less).

The Nature comment argues that we should also talk about using Solar Radiation Management to partially offset global warming. Most studies look at bringing the temperature down to pre-industrial levels, but we could also make smaller reductions. For example, we could stabilise the temperature in the tropics. Then the rest of the planet would still warm, but the impacts in poor and thus vulnerable countries would then be reduced.

Goe-interventions are typically accompanied by academic debates about global governance of such a system. We have seen how good that works for the original problem, geo-engineering by carbon dioxide. In case of carbon dioxide the response has been limited by the people willing to take the largest risks with other people's lives and property. (Hopefully economic forces will now block them.) The only possible climate treaty was one without any obligations beyond reporting back. Still the incompetent president of the historically largest polluter said fuck you to the entire world for no other reason than the pleasure of saying Fuck You!

Similarly the coolest coalition of the chilling will set the temperature. If the hotheads do not like that, I am sure the reasonable cool people will be willing to talk, if the talks are also about carbon dioxide emissions.



We would have to keep on managing the insolation for millennia or until someone finds a cheap way to remove carbon dioxide from the air. The largest danger is thus that humanity gets into trouble over these millennia and would no longer be able to keep the program up, the temperature would jump up quickly and make the trouble even worse. Looking back at our history since Christ was born and especially the last century, it seems likely that we will be in trouble once in a while over such a long period.

This danger could also be an advantage, just as the mutual assured destruction (MAD) with nuclear arms brought us a period of relative peace, the automatic triggering of Mad Max would force humanity to behave somewhat sensibly and make people who love war less influential.

My impression is that the main objection from scientists against geo-interventions is their worry about creating such an automatically triggered doomsday machine. Those people seem to think of a scenario without mitigation, where we would have to do more and more Solar Radiation Management. While carbon dioxide accumulates in the atmosphere over millennia, the stratospheric particles (after a volcanoes) are removed after a few years. So we would need to keep adding them to the stratosphere and if we do not reduce greenhouse gas emissions increasingly many particles.



I do not think humanity will forgo mitigation, but we will likely be too slow. My expectation is that we will stabilise the temperature, but after quite a lot of warming. Renewable energy is getting very cheap and still rapidly declining in price. Also batteries are declining in price. Thus I would see the energy transition as unstoppable for electrical power and private transport. That would break the political power of the fossil fuel industry and then make the rest of the transition (heating and industrial processes) a lot easier.

About 20 percent of historical warming is due to methane, which is mostly due to animal husbandry (read burping cows) and rice paddies. The residence time of methane is about a decade. It thus accumulates thus much less than carbon dioxide and would be something we could fight with a modest and importantly stable amount of Solar Radiation Management. Hopeful was a recent study that feeding cows seaweed reduces their methane emissions almost to zero. (There are many other ethical and environmental problems with industrial agriculture, but the global warming part of it would then be solved.)

At current costings per hectare, it will take 4 Trillion dollars to artificially restore corals on the #GreatBarrierReef lost from bleaching pic.twitter.com/IvuBJwt9Zy

— Terry Hughes (@ProfTerryHughes) 31 August 2017

Thus I expect us to stabilise the climate, but at a level that will be harmful. If we stabilise at 3°C of warming, would it not be better to reduce the warming to 2°C, 1.5°C, or our current 1°C. The internationally agreed upon 1.5 and 2°C levels are not "safe" levels, below them there are clear damages (and above them the word will not suddenly end).

There are scientific justifications for the 2°C level, for example looking at some tipping points in the climate system, but this level is not set by science. In the end it is a political compromise between the risks of climate change and political difficulty of changing the energy system. As a Dutch person, my compromise is to go back to the old temperature. Also if the warming would stop now immediately, sea level rise would continue for millennia.

The question is not whether it would be nicer not to have climate change, but whether a geo-intervention can improve the situation. Some worry that a geo-intervention would reduce the pressure to reduce greenhouse gas emissions. In a rational world that may partially be the case, although a geo-intervention would not stop the market forces moving us to renewable energy. In the real, not rational, world it may well do the opposite.



Most people like to see the world become a better place, some for all, some for a large group they identify with, some for their community, some for their family. That may make these people blind for the possibility that some do not mind if their own situation becomes worse, as long as it becomes even worse for others and relatively they “win”. Let’s call these people supremacists or fascists.

The term supremacy or Trump’s slogan “America first” is already a hint that these people want to be on top, it does not say that the top is a nicer place, it is a relative measure. When the Second World War still went "well" for the Nazi’s, they were on top, but the suffering was enormous, less so, but also for the Germans. The Nazi’s did not care, for them war and violence is a natural state. They call normal people “Good people”, seeing themselves as bad people, as people who enjoy bringing about suffering of humans they perceive as less valuable. America’s white supremacists dream of a race war, which will also bring a lot of suffering on the people they claim to love.

When these people hear Greenpeace argue that vulnerable people will suffer most from climate change, it would make sense that they like this and want more of this. It is not possible to convince these people that climate change is real, they already accept it is real, they only claim they do not. The best way to get more climate change is to claim that you do not accept the science of climate change. That way you can also convince some conservatives who do not like to see others suffering, but are naturally sceptical of any claim that powerful corporations can do something wrong and trust their politicians who work for the fossil fuel companies (campaign contributions, cosy jobs afterwards).

I think the fascists are stupid to listen to Greenpeace. Yes, more people will die in poor countries, that means they will have more kids and multiply faster. Living in a harsh environment makes you flexible and strong. Our power and pampered life style is based on a fragile just-in-time economy, where everything is optimised and thus every change produces damages. Where a mid-sized bank going bust can produce a decade long recession. If civilisation goes down, the poor will have the more useful skills.

The mitigation sceptical movement seems to be against all types of geo-intervention, except for emitting greenhouse gases. Reading between the lines when they complain that scientists spread too much fear, one almost gets the impression they fear climate change more than most. That could be because they are fighting to make the worst case scenario happen and expect to be “successful”.

The fascists among them would hate it when geo-interventions would make their life’s work mostly futile. If they are no longer fighting for a bad world that would make the transition again a lot easier.

Hopefully they will move on to lie about other stuff, preferably claims that are easily checkable, like the size of inaugurations. (It is a sad state of affairs, that I thought is was worthwhile to add a link.)



Let me end this post with a And-Then-There's-Physics-style last paragraph. I know a little about the quality of climate data, but this post is just written as a participant in the climate debate. As far as I can judge nearly all scientists worry about geo-interventions and many do not even like doing research on it. So even if pro-intervention people are very present in the media, I am an outlier. Feel free to point out my thinking mistakes and alternative solutions.

Related reading

Do dissenters like climate change?

Nature commentary: solar geoengineering reduces atmospneric carbon burden. (Open Access with this link.)

Gernot Wagner co-author of the book Climate Shock: It's time to take solar geoengineering seriously, even though it seems outlandish.

Raymond T. Pierrehumbert in The Bulletin of Atomic Scientists The trouble with geoengineers “hacking the planet”.

Reto Knutti, Joeri Rogelj, Jan Sedláček & Erich M. Fischer, 2016: A scientific critique of the two-degree climate change target. (pay-walled)

Frieler, K., Mengel, M., and Levermann, A.: Delaying future sea-level rise by storing water in Antarctica, Earth Syst. Dynam., 7, 203-210, doi: 10.5194/esd-7-203-2016, 2016.


* Top photo by NASA, Filament Eruption Creates 'Canyon of Fire' on the Sun used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.

Photo of thawing permafrost by NPS Climate Change Response used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.

Photo Collecting salt under desert sun by Armando G Alonso used with a Creative Commons Attribution-NonCommercial 2.0 Generic (CC BY-NC 2.0) license.

Photo of a strong African lady Use No Hooks by Michał Huniewicz used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.