Geoengineering – to do or not to do?

Climate change remains an uncomfortable topic. Politicians continue to state it is such an important problem, and then fail to do anything sufficient to solve it. There seems to be an idea amongst politicians that if everyone drove electric vehicles, all would be well. Leaving aside the question as to whether over the life of a vehicle the electric vehicle actually emits less greenhouse gas (and at best, that is such a close call it is unlikely to have any hope of addressing the problem) as noted in my post https://wordpress.com/post/ianmillerblog.wordpress.com/885

the world cannot sustain then necessary extractions to make it even vaguely possible. If that is the solution, why waste the effort – we are doomed.

As an article in Nature (vol 593, p 167, 2021) noted, we need to evaluate all possible options. As I have remarked in previous posts, it is extremely unlikely there is a silver bullet. Fusion power would come rather close, but we still have to do a number of other things, such as to enable transport, and as yet we do not have fusion power. So what the Nature article said is we should at least consider and analyse properly the consequences of geoengineering. The usual answer here is, horrors, we can’t go around altering the planet’s climate, but the fact is we have already. What do you think those greenhouse gases are doing?

The problem is that while the world has pledged to reduce emissions by 3 billion t of CO2 per year, even if this is achieved, and that is a big if, it remains far too little. Carbon capture will theoretically solve some of the problems, but it costs so much money for no benefit to the saver that you should not bet the house on that one. The alternative, as the Nature article suggests, is geoengineering. The concept is to raise the albedo of the planet, which reflects light back to space. The cooling effect is known: it happens after severe volcanic eruptions.

The basic concept of sending reflective stuff into the upper atmosphere is that it is short-term in nature, so if you get it wrong and there is an effect you don’t like, it does not last all that long. On the other hand, it is also a rapid fix and you get relatively quick results. That means provided you do things with some degree of care you can generate a short-term effect that is mild enough to see what happens, and if it works, you can later amplify it.

The biggest problem is the so-called ethical one: who decides how much cooling, and where do you cool? The article notes that some are vociferously opposed to it as “it could go awry in unpredictable ways”. It could be unpredictable, but the biggest problem would be that the unpredictability would be too small. Another listed reason to oppose it was it would detract from efforts to reduce greenhouse emissions. The problem here is that China and many other places are busy building new coal-fired electricity generation. Exactly how do you reduce emissions when so many places are busy increasing emissions? Then there is the question, how do you know what the effects will be? The answer to that is you carry out short-term mild experiments so you can find out without any serious damage.

The other side of the coin is, if we even stopped emissions right now, the existing levels will continue to heat the planet and nobody knows by how much. The models are simply insufficiently definitive. All we know is that the ice sheets are melting, and when they go, much of our prime agricultural land goes with it. Then there is the question of governance. One proposal to run small tests in Scandinavia ran into opposition from a community that protested that the experiments would offer a distraction from other reduction efforts. It appears that some people seem to think that with just a little effort this problem will go away. It won’t. One of the reasons for obstructing research is that the project will affect the whole planet. Yes, well so does burning coal in thermal generators, but I have never heard of the rest of the planet being consulted on that.

Is it a solution? I don’t know. It most definitely is not THE solution but it may be the only solution that acts quickly enough to compensate for a general inability to get moving, and in my opinion we badly need experiments to show what can be achieved. I understand there was once one such experiment, although not an intentional one. Following the grounding of aircraft over the US due to the Twin Tower incident, I gather the temperatures the following two days went up by over a degree. That was because the ice particles due to jet exhausts were no longer being generated. The advantages of an experiment using ice particles in the upper atmosphere is you can measure what happens quickly, but it quickly goes away so there will be no long term damage. So, is it possible? My guess is that technically it can be managed, but the practical issues of getting general consent to implement it will take so long it becomes more or less irrelevant. You can always find someone who opposes anything.

A Response to Climate Change, But Will it Work?

By now, if you have not heard that climate change is regarded as a problem, you must have been living under a flat rock. At least some of the politicians have recognized that this is a serious problem and they do what politicians do best: ban something. The current craze is to ban the manufacture of vehicles powered by liquid fuels in favour of electric vehicles, the electricity to be made from renewable resources. That sounds virtuous, but have they thought out the consequences?

The world consumption of petroleum for motor vehicles is in the order of 23,000 bbl/day. By my calculation, given some various conversion factors from the web, that requires approximately 1.6 GW of continuous extra electric consumption. In fact much more would be needed because the assumptions include 100% efficiency throughout. Note if you are relying on solar power, as many environmentalists want, you would need more than three times that amount because the sun does not shine at night, and worse, since this is to charge electric vehicles, which tend to be running in daytime, such electric energy would have to be stored for use at night. How do you store it?

The next problem is whether the grid could take that additional power. This is hardly an insurmountable problem, but I most definitely needs serious attention, and it would be more comforting if we thought the politicians had thought of this and were going to do something about it. Another argument is, since most cars would be charged at night, the normal grid could be used because there is significantly less consumption then. I think the peaks would still be a problem, and then we are back to where the power is coming from. Of course nuclear power, or even better, fusion power, would make production targets easily. But suppose, like New Zealand, you use hydro power? That is great for generating on demand, but each kWhr still requires the same amount of water availability. If the water is fully used now, and if you use this to charge at night, then you need some other source during the day.

The next problem for the politicians are the batteries, and this problem doubles if you use batteries to store electricity from solar to use at night. Currently, electric vehicles have ranges that are ideal for going to and from work each day, but not so ideal for long distance travel. The answer here is said to be “fast-charging” stops. The problem here is how do you get fast charging? The batteries have a fixed internal resistance, and you cannot do much about that. From Ohm’s law, given the resistance, the current flow, which is effectively the charge, can only be increased by increasing the voltage. At first sight you may think that is hardly a problem, but in fact there are two problems, both of which affect battery life. The first is, in general an overvoltage permits fresh electrochemistry to happen. Thus for the lithium ion battery you run the risk of what is called lithium plating. The lithium ions are supposed to go between what are called intercalation layers on the carbon anode, but if the current is too high, the ions cannot get in there quickly enough and they deposit outside, and cause irreversible damage. The second problem is too fast of charging causes heat to be generated, and that partially destroys the structural integrity of the electrodes.

The next problem is that batteries can be up to half the cost of the purely electric vehicle. Everybody claims battery prices are coming down, and they are. The lithium ion battery is about seven times cheaper than it was, but it will not necessarily get much cheaper because at present ingredients make up 70% of the cost. Ingredient prices are more likely to increase. Lithium is not particularly common, and a massive increase in production may be difficult. There are large deposits in Bolivia but as might be expected, there are other salts present in addition to the lithium salts. There is probably enough lithium but it has to be concentrated from brines and there are the salts you do not want that have to be disposed of, which reduces the “green-ness” of the exercise. Lithium prices can be assumed to go up significantly.

But the real elephant in the room is cobalt. Cobalt is not part of the chemistry of the battery, but it is necessary for the cathode. The battery works by shuttling lithium ions backwards and forwards between the cathode and anode. The cathode material needs to have the right structure to accommodate the ions, be stable so the ions can move in and out, have valence orbitals to accommodate the electron transfer, and the capacity to store as many lithium ions as possible. There are other materials that could replace cobalt, but cobalt is the only one where, when the lithium moves out, something does not move in to fill the spaces. Cobalt is essential for top performance. There are alternatives to use in current technology, but the cost is in poorer lifetimes, and there are alternative technologies, but nobody is sure they work. At present, a car needs somewhere between 7 – 20 kg of cobalt in its batteries, and as you reduce the cobalt content, you appear to reduce the life of the battery.

Cobalt is a problem because the current usage of cobalt in batteries is 48,000 t/a, while world production is about 100,000 t/a. The price is increasing rapidly as electric vehicles become more popular. At the beginning of 2017, a tonne of cobalt would cost $US 32,500; now it is at least $US 80,000. Over half the world’s production comes from the Democratic Republic of Congo, which may not be the most stable country, and worse, most of that 100,000 t/a comes as a byproduct from copper or nickel production. If there were to be a recession and the demand for stainless steel fell, then the production of cobalt would drop. The lithium ion batteries that would not be affected are the laptops and phones; they only need about 10 – 20 g of cobalt. Even worse, there are a lot of these batteries that currently are not being recycled.

In a previous post I noted there was not a single magic bullet to solve this problem. I stick to that opinion. We need a much broader approach than most of the politicians are considering. By broader, I do not mean the approach of denying we even have a problem.

This post is later than my usual, thanks to time demands approaching Easter, and I hope all my readers have a relaxing and pleasant Easter.