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Geoengineering: An Interim Strategy to Curb Global Warming? A Talk With John Latham

John Latham, a pioneer of cloud brightening technology, tells us about geoengineering, the deliberate manipulation of the earth’s climate to counteract global warming.

“Geoengineering” has become a buzzword in climate change discussions. Some critics view it as something to be avoided because of the unknown consequences it could have and others call it a band-aid for the climate crisis rather than a strategy which addresses the core problem of greenhouse gas emissions. While proponents view geoengineering as something that deserves attention because we are headed towards an uncertain future as we approach a so-called climatic “tipping point,” and the deliberate remediation of the earth’s climate may be our only hope to avoid catastrophe.

John Latham is a cloud physicist who has been working on a technology called marine cloud brightening for many years. He talked with VagabondJourney.com over telephone about his views on geoengineering, the current state of climate change, as well as what his proposed technology could do to help buy us time until a long term solution for global warming is found and utilized.

Geoengineering seems to be a bit of a buzzword that generates strong opinions. Do you endorse this word or do you prefer something else?

I think it’s an absolutely terrible word because it carries possible connotations of Dr. Strangelove and trying to change the climate of the world; in fact, it should be called something like climate restoration. What we’re trying to do, as far as possible, is to keep things as they are, not to change them. Inevitably, there would be some change but hopefully nothing like the change that would happen if we don’t do anything.

You published a paper in 1990 about cloud brightening technology. This was when global warming was hardly on anyone’s radar. Can you tell me more about how you came up with this idea and how long you’ve been working on it?

In those days, there wasn’t any significant public consciousness on the possibility of significant climate change and, in particular, the increase in temperature. At that time, I ran something called the Atmospheric Science Department at University of Manchester in England. Some of the people we interacted with were already beginning to conclude from measurements and knowledge of physics that If we kept on burning fossil fuels then we were going to get in big trouble because the burning produces carbon dioxide. As I’m sure you know, that gas, a lot of it, will remain in the atmosphere. What it does is absorb heat in the atmosphere that would otherwise escape from the Earth. So, there’s a warming because you still have the sunlight coming in and the amount that goes out to balance it to keep the Earth’s temperature steady would lessen because the carbon dioxide stops some of the radiation going out. So that’s the danger. I must have picked this up from 1 or 2 colleagues, because I’m not a climate scientist but have worked a lot with clouds.

What is Geoengineering?

Geoengineering is the deliberate manipulation of the Earth’s climate to counteract the effects of global warming from greenhouse gas emissions either through: 1)The removal of carbon from the atmosphere, thereby directly reducing the amount of greenhouse gasses, 2)Solar radiation management techniques, which aim to offset the effect of greenhouse gasses in the atmosphere by reducing the amount of solar radiation that the earth absorbs.

If we step back for a minute, clouds are very important in climate. Clouds reflect sunlight back into space. If clouds weren’t there, the Earth would be a lot warmer. Over the oceans, which cover about 75% of the earth, there is a cloud covering. About a third of the oceanic area has a cloud covering. These are the clouds we are suggesting might be made more reflective. At the moment, they bounce back about half of the sunlight. And the other half gets through. If we could somehow or other increase the refraction of sunlight back, that bounces back into space, then we could produce a cooling. If we could control it, we could hopefully produce a cooling that balances the warming that results from the burning of fossil fuels producing carbon dioxide.

The long term solution is for us to stop using fossil fuels. But, at the moment, despite all the worry about climate change, the burning of fossil fuels just keeps on increasing. That’s why we’re on a possible path to disaster.

Building off of that, we know climate change is a multifaceted concept that refers not only to the Earth’s temperature, but wind patterns and precipitation. From what I understand, this technology is addressing just global temperature, which is one aspect of climate change. When we talk about disastrous weather patterns, they are a combination of many factors including ocean temperature, wind patterns, rainfall, and climate. Do you think it is sufficient to stop the disastrous weather patterns?

You’ve asked a very good question there. You’re absolutely right. The problem is not simply that the Earth is getting warmer. Another major problem for example is the fact that ice caps are melting at the North Pole and the South Pole. That is dangerous because, first of all, the ice melts and so the sea level rises and there are many countries of the world that are basically at sea level.
I think Bangladesh is the best example. I may get some numbers wrong and apologize for that, but there are about a billion people in Bangladesh, and if sea level rose by 20 or 30 feet, which is quite conceivable, there would be no Bangladesh at all. There would be an exodus of people from that country, which would not be welcome by other, also very poor, countries that would find it hard to accommodate extra people. They might be very sympathetic, but it wouldn’t be surprising if they resisted the extra population.

The US army has been concerned about geoengineering and climate change for a long time. It’s been very quiet work. The worry they have is the wars that will happen when places dry out, when there is less water, when large parts of the Earth’s landmass become uninhabitable. It’s not just that the ice melts; it’s when water warms, it swells and so that adds to the increase in the level of the tide.

And the worst worry of all is that if we start warming, as we are doing, the high latitude regions, particularly near the North Pole, and land in Siberia for example, the ground is frozen year round and has been for hundreds of thousands of years. The word they use is permafrost to describe what that is. Trapped in the permafrost for chemical reasons that I’m not familiar with, is a lot of methane; a huge amount of methane. And, methane does what carbon dioxide does: it traps some outgoing heat. And methane is forty times more efficient than carbon dioxide. There isn’t as much methane as there is carbon dioxide, but it is so much more effective in trapping heat within the Earth’s system. If permafrost melts, we are in big trouble.

Those are interacting reasons why there are quite a number of dangers. Another one I suspect that is on your list is that rainfall patterns can change. Overall, if you warm atmosphere the rainfall amount will decrease. Actually, I’m not quite sure that that’s correct, but there are certain regions of the earth that will receive a lot less rain than they do. A lot of those countries, again it’s just the way the coin flips, are just the poorest countries of the world that are going to be the worst hit by climate change. Those countries need every drop of water they can get for irrigation, for growing crops, when there really isn’t enough rain. If that rainfall amount diminishes significantly, then starvation is going to happen.

What is Cloud Brightening?

Cloud brightening is a geoengineering technique that aims to make clouds “whiter” by spraying ocean water into the atmosphere, rendering it more reflective to sunlight in an effort to curb global warming. John Latham’s idea involves doing this with a fleet of autonomous ships, steered by satellite, each spraying hundreds of thousands of salt particles into the air every second.

On the topic of rainfall, there seems to be concern that some of these geoengineering technologies would impact global rainfall patterns in ways we cannot predict. What are your thoughts about that?

I think it’s another very important question. First of all, I think there should be an international agreement on geoengineering. I don’t think it was right for the guy that went and dumped a huge amount of iron in the ocean without telling anyone. It’s inevitable that the poorer countries suspect that they’re going to be fleeced, as they so often are, by the rich countries. I’ve not met anyone working on geoengineering whose motivation was not good.

I certainly feel, and colleagues also feel, that no geoengineering idea should ever be utilized unless it is established — well established — that there are no adverse consequences.

And rainfall is the one mentioned most. Regarding the marine cloud brightening that I’m working on, about 5 years ago, a very good computer modeling group in England, independent of us, did a study that our idea (marine cloud brightening) would certainly produce a cooling and could help restore the ice caps. They concluded reduction in rainfall in Amazonian region that would be unacceptable.

We’ve worked on that and we’ve worked with them since that and we confirm their results and our process involves seeding some of these clouds in such a way to make them reflect more energy.

If you see clouds in certain regions you can get bad effects. If we see it in other regions, then you don’t get those bad effects. So we have to be very, very careful that we examine all those things that could go wrong. If we can’t resolve those problems, we shouldn’t ever propose, and permission should never be given to, an idea that has a bad effect that can’t eliminate. Then it should be dropped.

How has the IPCC [The Intergovernmental Panel on Climate Change] received your proposed technology?

The IPCC is about to make a report on geoengineering ideas. I contributed to a small degree to what they produced almost 4 years ago [where] there was a brief mention of geoengineering.

Now it’s a much more well considered area of study because people are getting more and more conscious of the reality of climate change. So, what has been said so far has not been very detailed. One of my collaborators is on the IPCC panel has told me a bit unofficially about what will be coming and I think they’ll produce quite a comprehensive assessment of different ideas when that report comes out, which I think is within the next twelve months.

The Conference of Parties [The meeting of parties to the United Nations Framework Convention on Climate Change] is currently taking place. Is there a platform for geoengineering?

As far as I know, and I’m sorry I don’t have the full picture, I think that conference is mainly about reducing CO2 emissions. It’s a very important topic. It’s one that’s wholly unsatisfactory and the big countries are the worst polluters. The U.S., unfortunately, per capita gets the gold medal for producing carbon dioxide more than anyone else per head. Countries that are just starting to become fairly well off like India and China that have so many people, are manufacturing more cars, etc etc . . . [are] saying the wealthier world should be the ones to make the sacrifice. And no one will take responsibility. And some countries, including the U.S .,won’t sign the agreements.

Do you think that if there was enough political will to invest in renewable energy such as wind, solar, or hydro energy that we could control the planet’s climate and without nuclear therefore not employ geoengineering?

Geoengineering is never going to be the long term solution, all it can do is buy time. Renewable energy – wind is perhaps the most efficient in the global sense. And again, I’m not an expert on this, but here colleagues talk about it and say, ‘Yes, we should definitely look into all the ideas for renewable energy which are free from pain and bad effects.’ But indications are that that is not sufficient. It could be helpful, but not sufficient.

Do you think we’ve reached the so-called ‘tipping point’ in climate change where we need to do more than reduce emissions if we’re serious about a stable climate?

I hope and so do my colleagues that there never will be any need for geoengineering ideas to be deployed. But the fossil fuel burning countries, basically all of them, are being utterly irresponsible. The answer I get from people more informed on your question than I is that we are not in a situation yet which is totally irreversible but we are moving towards such a condition. And the rate we are moving depends on how much CO2 we continue to burn.

At the moment, it is just a plethora of lies. From the British Government, for example, that we are leading the world in reduction of CO2. It’s a lie. We are actually burning more and more each year. It’s a good question you’re asking. Even if we turn off CO2 burning now, which we couldn’t without very bad effects because then the energy supplies of the world would then not exist. We couldn’t do that, but even if we did, the heating will continue for quite a long time.

The ideas like marine cloud brightening are not designed to be a picture into the distant future. The idea is to try to find a way, roughly speaking, to hold things how they are until a clean form of energy that doesn’t change the climate is found. What that will be is not all that clear. Most people’s guess is that it will be nuclear, which has its own set of issues, but at least it doesn’t do to the atmosphere what we’ve been doing for 200 years now.

Legally, if you wanted to start using your technology, would you be able to? What is the procedure to start employing the marine cloud brightening technology?

In terms of deploying that idea or any idea, of which there are many, there is a general view apart from the idiot who threw all the iron in the ocean. None of these ideas should be deployed on a global scale unless there is international agreement.

What we would like to do, and we are not ready to do yet, is to seek permission to perform a field experiment on a scale that is very much less than the size of the Earth. Like 100 kilometers or 50 miles by 50 miles. We’d like to do experiments where we do release sea water droplets into the clouds where we do measurements using satellites, radar, and aircraft instrumentation and so on and actually measure whether or not, [and] under what circumstances, we could get an increase in reflectivity that could be helpful. We’d like to do the experiments when we’re ready for it. But we need the permissions and it will take us at least a couple of years to get to that point. And hopefully by that time there will have been international discussions and decisions made as to whether performing that field experiment is designed to see whether the idea really works. This idea will not be tried out globally, but tested out in the field.

Could this technology be seen as an “offset” where companies could potentially buy these offsets and then raise their cap on emissions?

We are not at that stage of our work. We are not interested in making money. Genuinely. We just want to examine a possible technique that could hold the Earth’s temperature, rainfall, and ice caps at roughly constant until some sort of new clean form of energy is initiated. So insofar as we can, we’re not prepared to deal with people who want patents, who want exclusive rights or anything. That’s entirely the wrong thing. It would again be capitalism running the show. There would be such opposition from poorer countries and quite rightly. They’d be exploited again. That’s a very big issue that we have to address. We’re not competent to do it. We can have our say, and be honest and detailed, but it’s got to be an international group that examines this and represents all countries. Something like the United Nations.

Certain organizations and individuals have taken a direct stance against geoengineering. Do you engage with these groups? If so, how?

We try to. We have a blog set up by one of the big names in geoengineering, Ken Caldeira at Stanford, and there have been communications with ETC for example. I find it really sad that there is friction between bodies like ETC, which want to help the planet, want to save the planet, want the poor countries to do better. That’s exactly what we want, but we’ve not convinced those people that we’re not out to help the rich countries at the expense of the poor countries, nor are we trying to play god, which is one accusation.

We’re trying to restore things. We’ve been playing god for 200 years since we’ve starting burning fossil fuels, and we want to try and compensate as best we can.

A very well known agency, whose name I’ve forgotten, that believes in helping the poor countries and they’ve just decided that geoengineering, if it’s properly monitored, is probably necessary. But there are some other nature-based, ecologically conscious groups who wouldn’t touch it with a barge pole. What we have to do is somehow or other maintain contact with those groups and see whether we can reach an agreement because the goals they want and the goals we want are the same.

At the moment, who is funding your research?

Basically we have no funding. We have had a little. That’s not quite true, but basically. To complete our work to the point of being ready to do field experiment, we would need $5 -10 million. Then to do the field experiment, that would cost another $40 million.

That can sound large, but we just published a paper presenting computations and arguments that suggest we could weaken hurricanes by seeding clouds to cool the ocean waters because hurricanes feed on hot water. If we could reduce the temperature, if it works . . .  then we could reduce category 5 hurricanes to category 4 or even category 3. The cost of Sandy is something like $50 billion. Compared with that one adverse incident and hurricanes year round then the cost of what we’re doing and the cost of what our colleagues are doing is utterly trivial.

Who are you looking to for funding? 

At the moment it’s tricky. We are all focusing our attention on work we do.
We published a paper in perhaps the most famous of all the scientific journals, called the Philosophical Transactions of the Royal Society, which Isaac Newton published some of the greatest papers of all time in the 1600s. We had a long paper in that journal.

We are open to any funding agency that makes no demand of secrecy of our work. It’s got to be absolutely open. We’re only trying to test out the idea, not utilize it on the global scale. The German government has put quite a bit of money into it. They’ve done quite a lot of work on our idea. But it’s not built up enough momentum. We haven’t got an efficient fundraising component to what we’re doing. We have some good noises, but not any money yet.

Sometimes the term “Geoengineering” gives us images of wild, bizarre sounding theories of ways to combat global warming. What is a lay person supposed to make of all these technologies?

There has been quite a bit of attention given to so-called geoengineering ideas in the media. The Discovery channel gave 9 or 10 one hour programs about it three years ago. In each one, a single idea was the only was examined. So, it got a good airing. The hurricane in New York gave rise to the idea of hurricane weakening. I’ve been interviewed on TV three times, even though our main emphasis is on the global warming. Slowly there is starting to be a distribution of information about these ideas. The general reaction seems to be we need to try these things out because we are moving to some kind of cataclysm.

A common criticism of employing geoengineering techniques is that we move away from trying to reduce emissions and allow polluters to continue polluting, letting them believe science will fix the problem. How do you respond to that concern?

Yet again, it is a very, very good question. I know some scientists, good scientists, concerned people who say we should never conduct geoengineering. They are agreeable that we test out the idea, but we should never do it because oil companies will use that as an excuse to keep on burning fossil fuels. Until they are stripped of the power they have and influence they have and the bribery they conduct (you can tell I’m prejudiced) and false reporting…all of those things are going on, and until governments take a tough stance on that, it’s going to be hard to resolve the question you asked.

More on Vagabond Journey: Geoengineering series

For more about John Latham and his ongoing research, be sure to visit his page at UCAR.


Filed under: Conservation, Environment, Interviews

About the Author:

Rozina Kanchwala is an avid reader, world traveler, seeker of social justice, environmentalist, and aspiring writer. She has lived, studied, and worked in a number of countries and has spent time with people from many walks of life. She believes that everyone has a story to tell and hopes to tell just a tiny fraction of these stories. has written 6 posts on Vagabond Journey. Contact the author.

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  • Jack December 3, 2012, 9:27 am

    Am I going to be the first person to say Chemtrails?!?

    I think messing with any system that you don’t understand is just plain stupid. I think they are just more big white elephants that will cost money and make problems worse or morph them into totally different problem….if they work at all.

    Why not have people instead stop buying worthless junk that they don’t need?

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    • Rozina December 3, 2012, 11:39 pm

      Thanks for your comments, but unfortunately getting people to stop buying worthless junk is no easy task.
      I think Mr. Latham hopes that we will never need to use geoengineering, but in the slight chance that we do, we should be prepared to. He acknowledges that his own technology is not yet ready and until it is, the thought of is should not even be considered.
      Unfortunately, we’ve already messed with a system that we did not understand. I do hope people will wake up soon and move away from the addiction to fossil fuels!

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    • Wade Shepard December 4, 2012, 8:12 pm

      Very true. But I think that most of the responsible scientists (not those pushing the technology for business interests) are more into testing the waters on geoengeering with extensive localized testing first. Also, at least from what John says above, this technology in any form is more or less meant to be a last resort option — or one to stave off a last resort scenario until we can come up with a better idea (like moving away from fossil fuels). Anyway, I think it’s a positive step to learn as much about these methods as possible (and what they teach us about climate as well) as it doesn’t look from here like we’re going to stop using massive amounts of greenhouse gas emitting fuels any time soon.

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  • Johan December 3, 2012, 11:26 am

    Time for the world to face it’s fear and go nuclear in a big way. No carbon emissions, no greenhouse gasses, no climate change. Yes nuclear is risky and scary, but the alternative is far worse. Its all about the ascendency of man and science, its time to find our courage and embrace a nuclear world.

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    • Wade Shepard December 4, 2012, 8:06 pm

      We’re entering “the future.” It’s interesting how we’re all at the edges of our seats wondering how it’s going to pan out.

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    • Rozina December 5, 2012, 1:24 pm

      I think solar and wind are the way to go. And I think it can be done if we remove the crazy subsidies going to the oil companies and really invest in these technologies.
      Look at Fukushima, chernobyl, and 3 mile island. I’m surprised nuclear still gets so much positive attention.

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  • Johan December 5, 2012, 1:56 pm

    Well I believe that successful people and cultures keep all their options open. Its always seemed a little foolish to limit one’s choices. So with that in mind I certainly support continued research into solar and wind, as well as wave energy, geothermal, biofuels, carbon recapture, cloud seeding, etc. Solar in particular, has nearly infinite promise. However, there is a difference between the future and now. And right now our efficiency at capturing solar is pitiful compared to even the most primitive plant or algae. Right now it is my opinion, emphasis on opinion, that nuclear is the most viable option on the table. But nuclear does involve a systemic complexity and risk that the other options avoid. It is a complicated matter living in this highly developed and complex world that we have created for ourselves over that last 2000 years or so.

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  • Kerick Walters December 5, 2012, 5:16 pm

    who do these people think they are that they have the right to just take it upon themselves to dump chemicals into the upper atmosphere to make it brighter like the planet Venus believing that Venus is bright as it is because it reflects away the sunlight so what do these idiots do they send probes to the planet Venus and discover that the main chemical composition of Venus’s upper atmosphere is the same as Earth’s but with different proportions and come up with a real humdinger which is to super heat the ionosphere via H.A.A.R.P. ( to mimic the solar temperature from the sun and they spray the chemical compound to mimic that of the Venus’s upper atmosphere. to, in their way of thinking reflect the light of the sun to cool the planet. these people need to be lined up and shot every last one of them. they have no idea what they are doing but they think they can play God and answer to nobody. the chemtrails have devastated this planet in the last 10 years far more than the automobile has in the last 100 years.

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    • Wade Shepard December 5, 2012, 6:57 pm

      It is my impression that Latham’s proposed technology involves shooting up sea salt from the ocean. Chemtrails, or any other conspiracy theory, is not the same as this.

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