IPCC Conclusion: We Are Cooked!

Recall the saying, “There are lies, damned lies, and statistics”. I would add a further term at the end – ” There are lies, damned lies, statistics, and models.” What sparked this bout of negativity? Well, last week I went to a talk from one of the NZ representative of the International Panel on Climate Change. The talk was headed, “Where are we, and how do we get out of this?” The entire talk was devoted to where we are, and it was fairly grim, and the second part, how do we get out of this, was blank. Maybe there is no way out. Anyway, let me try to recall what was said. If there are errors here from the IPCC, assume they are due to my faulty memory.

The first thing to note is the goal back in the 1990s was to limit greenhouse emissions so as to keep the increase in temperature to 1.5 degrees C above pre-industrial levels. One could question that as a goal because pre-industrial was the so-called “Little Ice Age”, and arguably that is not a good reference point. Be that as it may, the governments of the world agreed to work on limiting emissions. First there was the Rio agreement in 1992, then the Paris agreement, which is supposedly legally binding on 196 parties, and the aim was to “pursue efforts” to limit the temperature raise to 1.5 degrees.

So how are we doing? It is one of the less successful agreements, in my view. The object was to limit and reduce emissions of CO2; what has actually happened is we have doubled the rate of emissions, and much of that since the “legally binding 2016 agreement”. The original target was not to hit the 1.5 degree rise before the end of the century. If we extrapolate current trends, we strike it in this decade. Oops!

So what are the effects? Currently, the odd good thing, but mainly the outcomes are bad to awful. What is somewhat unexpected is the effects differ by hemisphere, possibly because the Southern Hemisphere has most of the ocean, and ocean has an albedo about a third of that of land, so it absorbs so much more heat. The greatest increase in local temperature has come from that Arctic; it is heating rapidly. Funnily enough, the Antarctic is not following, and there are even spots where it is cooling. The heating of the Arctic does little for sea level rise because the ice was always floating, but the Greenland Ice Sheet is shedding water at a rate of 270 billion t/a, which contributes to the rising sea levels. Antarctica is losing ice at a rate of about 150 billion t/a, mainly due to warmer water undercutting the ice and melting from below. The end position is unclear; climate models suggest the two large Antarctic ice sheets should collapse, but there are some claims that the ice sheets are growing. Recall my comment on models?

The  other problem is weather. The winds are part of a gigantic heat engine, and the winds strengthen as the temperature difference increases. Accordingly, the rapid heating of the Arctic will moderate the temperature difference in the Northern hemisphere. Although that is not a free pass because hurricanes and typhoons are generated by seawater evaporating, so they will get stronger as the planet heats. The other problem for the Northern hemisphere is quieter wind systems lead to longer and more severe droughts. For the Southern Hemisphere, as we are  finding out, the wind systems become stronger and we have “atmospheric rivers” pouring large amounts of water from the tropics over us. But one interesting fact is that precipitation seems to be increasing over Antarctica. That may save us somewhat from being too inundated by sea-level rise.

So where does this leave us? Well, the IPCC has modelled a huge number of possible futures, but my feeling is, almost all of them will not happen. We know the situation is getting bad, but what is being done to fix things? Not a lot. And it is not that good plans are not being implemented. If this talk was indicative, we have NO GOOD PLANS. Does that mean we cannot do anything? No it does not. But as General Wesley Clark said there are two sorts of plans: those that won’t work and those that might work. You have to take one that might work and make it work, And herein lies some problems. We don’t know for sure what will work, although some seem highly probable, but we also have no mechanism to make them work. Recall what I said about the rate of emissions doubling when everyone was supposed to be reducing them? We have governments carrying out emissions trading schemes, as if that would solve the problem, but it is just raising costs; the rate of emissions is increasing. There might be a legally binding treaty, but if everyone is violating it, what good is that? There is no method to get governments to impose plans that might work, and politicians, usually, could not tell whether a plan could work, although they may well predict, correctly, if left to them it would not work. This is a highly technical problem that has to be understood to solve it. Politicians simply do not have the technical background.

Advertisement

How to Beat the Potential Lithium Shortage?

By now, lithium is probably recognized as a useful material and is considered to be critical for dealing with climate change. A recent  paper in Nature (vol 616, 245) discussed some of the issues. In 2018, demand for lithium was about 55,000 t/a, by 2025 it is expected to reach 150,000 – 190,000 t/a, and by 2100 it could reach 700,000 t/a. The IEA predicts that by 2030, only about half of what is required could be delivered. The production of lithium is currently complicated. Ores are roasted at 1100 degrees C, then baked in acid at 250 degrees C to leach out acid solubles. Apparently about a half a dozen chemical reactions are carried out to get rid of impurities, and the solution is evaporated to make lithium carbonate. To make a tonne of lithium salt, you need 60 MWh of electricity and 70 cubic meters of water, while the overall process, including mining, emits up to 35 t of CO2. Worse, most of the lithium occurs in basically dry areas, such as in Western Australia. The waste includes elements such as arsenic, thallium, chromium uranium and thorium. Finally, by 2030 there will be roughly 8 million t of sodium sulphate as a byproduct. This arises th4rough the lithium carbonate being made bey taking lithium sulphate and sodium carbonate. Lithium carbonate is only soluble in water at about 1% at 20 degrees C.

The need for an improved extraction process is obvious, but just because the need is obvious does not mean it will be easy. One method proposed is to find a sorbent that you pass the solutions through and only the lithium is absorbed. Ther e appears to be only one problem with this proposal: as yet we do not have such a sorbent. Is one possible? I would guess yes, but it may take some time to develop, and of course you want to be able to get the lithium out of the sorbent and reuse it. What are the prospects? It is possible to make substances like zeolites with specifically sized channels and have functional groups in them that will absorb the desired product. My guess is the zeolites are unsatisfactory because their absorbing properties come for cationic charge, which would presumably repel lithium, but there is plenty of scope to have the concept played out with something more suitable. So I would give that option a firm “maybe”.

The next suggestion is electrolysis. My concern is that the impurities noted above would coat the electrodes, while the lithium would stay in solution. It may well be somewhat more concentrated around the anode, but they will not deposit. Basically, what is being done is to electrolyse water, and coat some electrodes. Unless there is some undisclosed trick, I give this a fairly firm “dubious”.

The Nature paper suggests that one way to use the otherwise waste sodium sulphate (which is very water soluble) would be to convert it back to sodium hydroxide and sulphuric acid. No route was suggested, and while this is possible, my guess is it would be extremely expensive. Of course, the solution would have a certain amount of lithium carbonate as well.

The digging up of rocks could be avoided by passing water into the mineral bed, similar in concept to fracking. That, to me, would almost certainly work, although at what cost remains to be seen. There would still need to be  good purification techniques.

Another alternative noted in the paper is not to bother purifying the lithium, but to use disordered rock salts, which are more abundant than cobalt or nickel. At this point the article seems to overlook why cobalt is used in the first place: it can form a trivalent cation as well as a divalent one. When the lithium changes oxidation state at the anode, something has to do the opposite at the cathode, AND it has to do so without a volume change. If it fails and has a volume change, the cathode will fracture after so much charging and the battery dies. The article notes these disordered rock salts require high voltage charging, at which point they become unstable. Not desirable. There are so many things that we do not know how to get around for this to work I consider it extremely doubtful.

Recycling sort of works. The batteries are shredded ( and hopefully do not catch fire because  a lithium fire is almost impossible to put out), then the lot is heated to recover the metals as an alloy, while the lithium is in a slag. It is then treated like an ore. That needs a better process.

So, where does this end up? In my opinion the most likely outcome will be a different type of battery. A sodium ion battery will have unlimited sodium, but since it has yet to work we do not know what else it requires. My bet goes back to the chemistry I suggested in my first Mars novel: an aluminium chlorine battery, although prior to charging it merely contains aluminium chloride. Neither of those elements are in short supply.

Cows and Climate Change

There is no doubt the climate is changing. When I as a child, tornados happened in Kansas. Now they happen here with some sort of regularity, and we have had a sequence of ex-tropical cyclones and cyclones over summer. Things have to be done, but they have to be constructive. One problem is the issue can only be understood in terms of science and the level of scientific understanding with decision makers is abysmal. It is like asking the blind to sort out dangerous chemicals by reading the labels. Consider the issues of cows. Cows burp methane. Methane is a greenhouse gas. Therefore we need to eliminate cows. Pass the oatmilk.

A recent paper in Nature Geoscience (R. J. Allen, https://doi.org/10.1038/s41561-023-01144-z, 2023) appears to throw proverbial spanners in works relating to methane. Data suggests that since pre-industrial times, methane levels have risen from approximately 0,75 ppm to 1.8 ppm. I am sceptical of the first figure; how did they measure it then, and more interestingly, why did they measure it then? I dislike calculated figures because the calculations tend to be loaded with the bias of whoever does the calculations. If an assumption is required, it becomes a loaded one. However, if we accept those figures, models tell us this leads to an effective radiation forcing of just under half a watt per square meter. Thus methane is a serious problem, at least according to a disparate bunch that includes vegans, those who accuse dairy milk of causing cancer, and a group who protest just about everything. The problem is that ruminants, including cows, emit methane, so the argument goes that banning cows would go a long way to solving the problem.

However, methane has a relatively short lifetime in our atmosphere (about a decade), when it undergoes a sequence of oxidative changes that eventually lead to carbon dioxide and since all the carbon came from plant material, and hence the atmosphere, it is not clear to me that banning dairying would make much difference. The vegans probably also ignore the fact that more methane appears to come from rice paddies. I am not suggesting that we do nothing about the methane. Anything that reduces a greenhouse gas is useful.

However, the point of this paper is that methane is not as bad as current models suggest. Models that only focus on the longer wavelength greenhouse effects overestimate the effect of methane by about 30%. This is because methane absorbs short wavelength UV in the upper atmosphere, and causes photochemistry to make compounds that absorb further longer wave-length electromagnetic radiation. This cools the surface because the high energy photons convert their energy to heat when they reach the surface of the  planet. There is less heat if they don’t get there.

An even larger effect (approximately 60% offset) arises if we include enhanced cooling due to cloud rapid adjustments. We get increased lower altitude clouds, which enhance the reflection of short wavelength light, and we get decreased high level clouds, which enhances outgoing longer wavelength radiation. This does not mean methane is good; it remains a greenhouse gas, but what it means is that everything is far more complicated than most models accept. Also, it cannot hurt to reduce emissions. However, equally, the extremes promoted by the extreme protestors are simply not valid.

A second proposal (Schmitz et al.  Nature Climate Change https://doi.org/10.1038/s41558-023-01631-6 2023) may seem a little odd. The objective is to enhance carbon capture  and storage in plants, soils and sediments. They do this by protecting and restoring wild animals, and restoring their ecosystem. The argument is such an ecosystem contains more carbon than farmland, or worse, wasteland, or in one case, waste space. The way this works is that a diversity of animal species with medium to large bodies assist seed dispersal and germination of large-seeded trees with carbon-dense wood, herbivory that reduces  plant competition and increases soil nutrient supply and enhances soil carbon storage. In terms of increases of CO2 reduction, in Mt/year, wildebeests on the savannah will provide 4.4, the musk ox 30, the grey wolf 260, and the champions, fish, 5,500. By simply protecting species currently there we can secrete 5.8 Gt of CO2 / annum. By restoring species we can go further, again in Mt/a, the African elephant, 13, bison 595, and the total comes to 6.4 Gt/a. (If you notice the numbers don’t quite add up, that is because I left out minor contributions.) Now surely pastoral cows also increase soil nutrient supply and enhance soil carbon storage. It also shows it is necessary to consider the whole system, and not cherry pick the facts that strengthen your case.

None of this suggests that we do not have a problem with greenhouse gas emissions. What it does suggest is there may be a multitude of ways to solve the problem, and contributions can come from a variety of sources.

Science and Society

An interesting question is to what extent should a person’s loyalties lie towards society? Suppose you own a business in a mall, and you happen to know that right now business is going well and lots of electronic transactions are going into your account. You are making money hand over fist, but by some means you learn there is a bomb somewhere in the mall,  but you are reasonably confident that nobody in your premises will be seriously injured when it goes off . Do you immediately clear the mall, or do you keep quiet for a while and let the money keep flowing? You might think the answer to that is obvious, but is it?

Now let us shift the problem down the chain of responsibility. An employee of the business believes there is a gas leak down the other end of the mall. Again, the business he works for will be safe, but he suspects that if he stops the flow of money he may well be fired. What does he do? Now, let us shift the imminence. You have some engineering knowledge and you are employed by the owner of the Christchurch TV building after the first earthquake, and you notice some of the floors are not level. You look up the architectural plans and you see the floors are debatably not properly anchored to the walls. Do you blow the whistle and get everyone out, at the risk of being fired, or let things stay, on the basis the building is safe enough now, and it withstood a serious earthquake? Finally, in each case, you are the owner, and a worker brings the information to you. What do you do?

With your answers to those questions safely established, now consider that according to Chemistry World (Feb. 2023) in 1977 the scientists at Exxon Mobil had completed some extremely capable climate modelling and had reached conclusions similar to what few other reached until the start of the new millennium. A study of Exxon-Mobil’s internal reports clearly showed the effects of mankind’s burning of fossil fuels, and these could be easily separated from natural effects. ExxonMobil kept insisting the science was too uncertain to know when, or if, human-caused global warming might be measurable. The ExxonMobil scientists predicted 2000 +/- 5 years. They just made it -the IPCC declared it was measurable in 1995.  Thus armed with excellent scientific evidence, the Chief Executives Raymond and Tillerson insisted there was a  “high degree of uncertainty” in climate models. Tillerson was CEO from 2006 to 2017 when the evidence was in that the predictions were accurate and if anything under-estimated the adverse effects. Further, ExxonMobil had a long history of funding  third parties to make misleading claims on climate change. Armed with that experience, Tillerson  subsequently became Secretary of State under Donald Trump. Had ExxonMobil spent such funds on promoting research to find the answers to the problems with climate change, we would be much better off. Interestingly, ExxonMobil’s defence regarding the misleading statements is that free speech is protected under the Constitution. Of course, “free speech” that is demonstrably wrong that is made to gain money is also known as fraud, and that is less well protected.

What particularly annoys me is that part of the solution may lie with biofuels. After cyclone Gabrielle, a huge amount of forestry waste was washed down into rivers and has become a major problem. That could be turned into liquid fuel as could the organic fraction of municipal waste by hydrothermal liquefaction. It is possible to do this in a variety of ways, I have done it in the lab, there has previously been a demonstration plant proposed to be built in the US, but was abandoned after the price of oil slumped. And we know the Bergius process converted lignite to liquid fuels, with Germany making over a million tonnes this way through 1944, despite plant being bombed. ExxonMobil had the internal skills to address the engineering issues and could have made this a possible option now. It would not solve everything, but it would have used their experience to provide a partial solution.

Switching slightly, some readers may recall my fascination with aluminium/chorine batteries. The reason is that aluminium is easily available, and in principle offers a large capacity because while one atom of lithium provides work from one electron, aluminium has three. I suggested fuel cells based on the chemistry in my e-novel Red Gold because aluminium and chlorine would be readily available on Mars. Now, a novel battery has been claimed (Angew. Chem. Int. Ed. 2023, 62, e202216797) with a phenoxazine cathode (no cobalt!). A gram is claimed to have a capacity of 133 mAh at 0.2A, and has run for 50,000 cycles with no loss. If these can be manufactured with such performance, general reasonably priced electric vehicles become a possibility.

Climate Change: A Space Solution”?

By now, many around the world will have realized we are experiencing climate change, thanks to our predilection for burning fossil fuels. The politicians have made their usual platitudinous statements that this problem will be solved, say twenty years out. It is now thirty years since these statements started being made, and we find ourselves worse off than when the politicians started. Their basic idea seems to be that the crisis gets unmanageable in, say, sixty years, so we can leave it for now. What actually happens is, er, nothing in the immediate future. It can be left for politicians thirty years out from now. Then, when the thirty years has passed it is suddenly discovered that it is all a little harder than expected, but they can introduce things like carbon trading, which employs people like themselves, and they can exhort people to buy electric cars. (If you live somewhere like Calgary and want to go skiing at Banff, it appears you need to prepare your car four hours before using it, or maintain battery warmers because the batteries do not like the cold one bit.)

Bromley et al. in PLOS Climate (https://doi.org/10.1371/journal.pclm.0000133) have a solution. To overcome the forcing of the greenhouse gases currently in the atmosphere, according to this article all you have to do is to reduce the solar input by 1.8%. What could be simpler? This might be easier than increasing the albedo.

The question then is, how to do this? The proposed answer is to take fine fluffy dust from the Moon and propel it to the Earth-Sun L1 position. This will provide several days of shading, while the solar winds and radiation slowly clear this dust away. How much such dust? About ten billion kg, which is about a thousand times more mass than humans have currently ever sent into space. Over a ten year period, this corresponds to a sphere of radius roughly 200 m, which corresponds to the annual excavation from many open pit mines on Earth. The advantage of using the Moon, of course is that the gravitational force is about 17% that of Earth so you need much less energy to eject the dust. The difficulty is that you have to put sufficient equipment on the Moon’s surface to gather and eject the dust. One difficulty I see here is that while there is plenty of dust on the Moon, it is not in a particularly deep layer, which mean the equipment has to keep moving. Larger fluffy particles are apparently preferred, but fluffy particles would probably be formed in a fluid eruption, and as far as we know, that is less likely on the Moon.

Then there are problems. The most obvious one, apart from the cost of the whole exercise, is the need for accuracy. If the dust is outside the lines from the edges of the Sun-Earth, then the scattering can increase the solar radiation to Earth. Oops. The there is another problem. Unlike L4 and L5, which are regions, L1 really is a point where an object will corotate. If a particle is even 1 km off the point, it could drift away by up to 1000 km in a year, and if it does that, perforce it will drift out of the Sun-Earth line, in which case the dust will be enhancing the illumination of Earth. Again, oops. Added to this are a small number of further effects, the most obvious being solar wind and radiation pressure which will push objects away from L1.

The proposed approach is to launch dust at 4.7 km/s towards L1, and do it from the Moon when the Moon is close to being in line, so that the dust, as it streams towards L1 continues to provide shielding while it is in-flight. The launching would require 10^17 J, which is roughly the energy generated by a few square km of solar panels. One of the claimed advantages of this is that the dust could be sent in pulses, timed to cool places with major heat problems. It is probably unsurprising that bigger particles are less efficient at shading sunlight, at least on a per mass scale, simply because there is mass behind the front surface doing nothing. Particles too small neither last very long in the required position, nor do they offer as much shielding. As it happens, somewhat fortuitously, the best size is 0.2 μm, and that happens to be the average size of lunar regolith dust.

One of the advantages claimed for this method is that once a week or so is over, there are no long-term consequences from that dust. One of the disadvantages is that which goes for any planetary engineering proposal: What is the minimum agreement required from the world population, how do you get it, and what happens if someone does it anyway? Would you vote for it?

This and That from the Scientific World

One of the consequences of writing blogs like this is that one tends to be on the lookout for things to write about. This ends up with a collection of curiosities, some of which can be used, some of which eventually get thrown away, and a few I don’t know what to do about. They tend to be too short to write a blog post, but too interesting, at least to me, to ignore. So here is a “Miscellaneous” post.

COP 27.

They agreed that some will pay the poorer nations for damage so far, although we have yet to see the money. There was NO promise by anyone to reduce emissions, and from my point of view, even worse o promise to investigate which technologies are worth going after. Finally, while at the conference there were a number of electric buses offering free rides, at the end of the conference these buses simply disappeared. Usual service (or lack thereof) resumed.

Fighting!

You may think that humans alone fight by throwing things at each other but you would be wrong. A film has been recorded ( https://doi.org/10.1038/d41586-022-03592-w) of two gloomy octopuses throwing things at each other, including clam shells. Octopuses are generally solitary animals, but in Jervis Bay, Australia, the gloomy octopus lives at very high densities, and it appears they irritate each other. When an object was thrown at another one, the throw was far stronger than when just clearing stuff out of the way and it tended to come from specific tentacles, the throwing ones. Further, octopuses on the receiving end ducked! A particularly interesting tactic was to throw silt over the other octopus. I have no idea what the outcome of these encounters were.

Exoplanets

The star HD 23472 has a mass of about 0.67 times that of our sun, and has a surface temperature of about 4,800 degrees K. Accordingly, it is a mid-range K type star, and it has at least five planets. Some of the properties of these include the semi-major axis a (distance from the star if the orbit is circular), the eccentricity e, the mass relative to Earth (M), the density ρ  and the inclination i. The following table gives some of the figures, taken from the NASA exoplanet archive.

Planet     a              e            M        ρ           i

b           0.116      0.07       8.32      6.15      88.9

c           0.165      0.06       3.41      3.10      89.1

d           0.043      0.07       0.55      7.50      88.0

e           0.068      0.07       0.72      7.50      88.6

f           0.091      0.07       0.77       3.0        88.1

The question then is, what to make of all that? The first thing to notice is all the planets are much closer to the star than Earth is to the sun. Is that significant? Maybe not, because another awkward point is that the inclinations are all approaching 90 degrees. The inclination is the angle the orbital plane of the planet makes with the equatorial plane of the star. Now planets usually lie on the equatorial plane because that was also the plane of the accretion disk, so something has either moved the planets, or moved the star. Moving the planets is most probable, and the reason the inclinations are all very similar is because they are close together, and they will probably be in some gravitational resonance with each other. What we see are two super Earths (b and c), two small planets closest to the star, which are small, but very dense. Technically, they are denser than Mercury in our system. There are also two planets (c and f) with densities a little lower than that of Mars.

The innermost part of the habitable zone of that star is calculated to be at 0.364 AU, the Earth-equivalent (where it gets the same radiation as Earth) at 0.5 AU, and the outer boundary of the habitable zone is at 0.767 AU. All of these planets lie well inside the habitable zone. The authors who characterised these planets (Barros, S. C. C. et al. Astron. Astrophys. 665, A154 (2022).) considered the two inner planets to be Mercury equivalents, presumably based on their densities, which approximate to pure iron. My guess is the densities are over-estimated, as the scope for error is fairly large, but they certainly look like Mercury equivalents that are somewhat bigger than our Mercury

Laughing Gas on Exoplanets

One of the targets of the search for exoplanets is to try and find planets that might carry life. The question is, how can you tell? At present, all we can do is to examine the spectra of atmospheres around the planet, and this is not without its difficulties. The most obvious problem is signal intensity. What we look for is specific signals in the infrared spectrum and these will arise from the vibrations of molecules. This can be done from absorptions if the planet transits across the star’s face or better (because the stellar intensity is less a problem) from starlight that passes through the planet’s atmosphere.

The next problem is to decide on what could signify life. Something like carbon dioxide or methane will be at best ambiguous. Carbon dioxide makes up a huge atmosphere on Venus, but we do not expect life there. Methane comes from anaerobic digestion (life) or geological activity (no life). So, the proposal is to look for laughing gas, better known as nitrous oxide. Nitrous oxide is made by some life forms, and oddly enough, it is a greenhouse gas that is becoming more of a problem from the overuse of agricultural fertilizer, as it is a decomposition product of ammonium nitrate. If nothing else, we might find planets with civilizations fighting climate change!

COP 27 – the 27th Cop-out??

Currently, a number of parties have descended on Sharm el-Sheikh for COP 27. This is the 27^th “Conference of the Parties” to deal with climate change. Everybody, by now, should be aware that a major contributor to climate change is the increased levels of carbon dioxide in the atmosphere, and we have to reduce emissions. In the previous 26 conferences various pledges were made to reduce such emissions, but what has happened? According to Nature, CO2 emissions are set to reach a record high of 37.5 billion tonne in 2022. So much for a controlled reduction of emissions. In my opinion, the biggest effect from such conferences is the increased emissions due to getting all the participants to them. In this context there are apparently over 600 fossil fuel lobbyists at this conference. So the question then is, why has so little been achieved?

My answer is the politicians took the easy way out: to be seen to be doing something they implemented a carbon trading scheme. This allows money to flow, and the idea was that economics will make people transition to non-fossil-based energy by raising the price of the fossil fuels. To make this look less like a tax, they then allowed the trade of credits, and politicians issued credits to “deserving causes”. There were two reasons why this had to fail: the politicians had the ability to sabotage it by issuing credits to those it favoured, and secondly, there are no alternatives that everyone can switch to. Therein lies the first problem. Price does not alter activity much unless there is an alternative, and in most cases there is no easy alternative.

The second one is that even if you can develop alternatives, there is far too much installed capacity. The economies of just about every country are highly dependent on using fossil fuel. People are not going to discard their present vehicles and join a queue to purchase an electric one. They are still selling new petroleum-powered vehicles, and a lot of energy has been invested in making them. Like it or not, the electricity supply of many countries is dependent on coal-fired generation, and it costs a lot to construct a new plant to generate electricity. No country can afford to throw away their existing generation capacity.

In principle, the solution for electricity is simple: nuclear. So why not? Some say it is dangerous, and there remains the problems of storing wastes. It is true that people died at Chernobyl, but that was an example of crass incompetence. Further, in principle molten salt reactors cannot melt down while they also burn much of the waste. There is still waste that has to be stored somewhere, but the volume is very small in comparison. So why is this not used? Basically, the equipment has not been properly developed, the reason being that reactors were first designed so they could provide the raw material for making bombs. So, when the politicians recognized the problem at the end of the 1980s, what should have happened is that money was invested for developing such technology so that coal-fired power could be laid to rest. Instead, there was a lot of arm-waving and calls for solar and wind power. It is true these generate electricity, and in some cases they do it efficiently, however they cannot handle main load in most countries. Similarly with transport fuels. Alternative technologies for advanced biofuels were developed in the early 1980s, but were never taken to the next stage because the price of crude oil dropped to very low levels and nothing could compete. The net result was that technology was lost, and much had to be relearned. We cannot shut down the world industries and transport, and the politicians have refused to fund the development of alternative fuels.

So, what will happen? We shall continue on the way we are, while taking some trivial steps that make at least some of us, usually politicians, feel good because we are doing something. Unfortunately, greenhouse gas levels are still rising, and consider what is happening at the levels we are at. The Northeast Greenland Ice Stream is melting and the rate of melt is increasing because the protection from the Zachariae Isstrøm glacier that protected the coastal part of the ice stream broke off. Now, warmer seawater is penetrating up to 300 km under the ice stream. Global ocean levels are now predicted to rise up to a meter by the end of the century from the enhanced melting of Greenland ice. More important still is Antarctica. There is far more ice there, and it has been calculated that if the temperatures rose by four degrees Centigrade above pre-industrial levels up to two thirds of that ice could go.

Unfortunately, that is not the worst of the problems. If the climate heats, food becomes more difficult to provide. The most obvious problem is that most of the very best agricultural land is close to sea level, so we lose that. But additionally, there will be regions of greatly increased drought, and others with intense floods. Neither are good for agriculture. Yet there is an even worse problem: as soil gets hotter, it loses carbon and becomes less productive, while winds tend to blow soil away. So, what can we do about this? Unfortunately, it has to be everyone. We have to not only stop venting greenhouse gases into the atmosphere, but we have to work out ways to take it out. Stop and ask yourself, does your local politician understand this? My guess is no. Does your local politician understand what a partial differential equation means? My guess is no.

Trees for Carbon Capture, and Subsequent Problems

A little over fifty years ago, a 200 page book called The Limits to Growth was published, and the conclusion was that unless something was done, continued economic and population growth would deplete our resources and lead to global economic collapse around 2070. Around 1990, we predicted that greenhouse gases would turn our planet into something we would not like. So, what have we done? In an organized way, not much. One hazard with problem solving is that focusing on one aspect and fixing that often simply shifts it, and sometimes even makes it worse. Currently, we are obsessed with carbon dioxide, but all we appear to be doing is to complacently pat ourselves on the back because we shall be burning somewhat less Russian gas and oil in the future, oblivious to the fact that the substitute is likely to be coal.

One approach to mitigate global warming involves using biomass for carbon capture and storage (See Nature vol 609, p299 – 305). The authors here note that the adverse effects of climate change on crop yields may reduce the capacity of biomass to do this, as well as threaten food security. There are two approaches to overcoming the potential food shortage: increase agricultural land by using marginal land and cutting down forests, or increase nitrogen fertilizer. Now we see what “shifting the problem” means. If we use marginal land, we still have to increase the use of nitrogen fertilizer. This leads to the production of nitrous oxide gas, and these authors show the production of nitrous oxide would be roughly three times as effective as a greenhouse gas as the saving of carbon dioxide in their model. This is serious. All we have done is to generate a worse problem, to say nothing about the damage done to the environment. We have to leave some land for animals and wild plants.

There is a further issue: nitrogen fertiliser is currently made by reacting natural gas to make hydrogen, so for every tonne of fertilizer we will be making something like a tonne of CO2. Much the same happens if we make hydrogen from coal. Rather interestingly for such a paper, the authors concede they may have over-estimated the problems of food shortages on the grounds that new technology and practices may increase yields.

Suppose we make hydrogen by electrolysing water? Ammonia is currently made by heating nitrogen and hydrogen together at 200 times atmospheric pressure. This is by no means optimal, but higher pressures cost a lot more to construct, and there are increasing problems with corrosion, etc. Hydrogen made by electrolysis is also more expensive, in part because electricity is in demand for other purposes, and worse, electricity is also made at least in part by burning fossil fuels, and only a third of the energy is recovered as electricity. When considering a new use, it is important to not that the most adverse in terms of cost and effectiveness must be considered. Even if there are more friendly ways of getting electricity, you get favourable effects by doing nothing and turning off the adverse supply, so that must be assigned to your new use.

There is, however, an alternative in that electricity can directly reduce nitrogen to nitride in the presence of lithium, and if in the presence of a proton-donating substance (technically an acid, but not as you would probably recognize) you directly make ammonia, with no high pressure. So far, this is basically a laboratory curiosity because the yields and yield rates have been just too small, but there was a recent paper in Nature (vol 609, 722 – 727) which claims good increased efficiency. Since the authors write, “We anticipate that these findings will guide the development of a robust, high-performance process for sustainable ammonia production.” They do not feel they are there yet, but it is encouraging that improvements are being made.

Ammonia would be a useful means of carrying hydrogen for transport uses, but nitrogen fertilizer is important for maintaining food production. So can we reduce the nitrous oxide production? Nitrous oxide is a simple decomposition product of ammonium nitrate, which is the usual fertilizer used, but could we use something else, such as urea? Enzymes do convert urea to ammonium nitrate, but slowly, and maybe more nitrogen would end up in the plants. Would it? We don’t know but we could try finding out. The alternative might be to put lime, or even crushed basalt with the fertilizer. The slightly alkaline nature of these materials would react in part with ammonium nitrate and make metal nitrate salts, which would still be good fertilizer, and ammonia, which hopefully could also be used by plants, but now the degradation to nitrous oxide would stop. Would it? We don’t know for sure, but simple chemistry strongly suggests it would. So does it hurt to do then research and find out? Or do we sit on our backsides and eventually wail when we cannot stop the disaster.

Burying Carbon Dioxide, or Burying Cash?

In the last post, I expressed my doubt about the supply of metals for electric batteries. There is an alternative to giving up things that produce CO2 and that is to trap and sequester CO2. The idea is that for power stations the flu gases have the CO2 removed and pumped underground. That raises the question, how realistic is this? Chemistry World has an article that casts doubt, in my mind, that this can work. First, the size of the problem. One company aims to install 70 such plants, each capable of sequestering 1 million t of CO2. If these are actually realized, we almost reach 0.2% of what is required. Oops. Basically, we need to remove at least 1 billion t/a to stand still. This problem is large. There is also the problem of how we do it.

The simplest way is to pass the flu gases through amine solvents, with monoethanolamine the most common absorbent used. Leaving aside the problem of getting enough amine, which requires a major expansion of the chemical manufacturing industry, what happens is the amine absorbs CO2 and makes the amine carbonate, and the CO2 is recovered by heating the carbonate and regenerating the amine. However, the regeneration will never be perfect and there are losses. Leaving aside finding the raw materials actually synthesizing the amine takes about 0.8 MWh of energy, the inevitable losses mean we need up to 240 MWh every year to run a million tonne plant. We then need heat to decompose the amine carbonate, and that requires about 1 MWh per tonne of CO2 absorbed. Finally, we need a little less than 0.12 MWh per tonne of CO2 to compress it, transport it and inject it into the ground. If we wanted to inject 1 billion t of CO2, we need to generate something like 840 TWh of electricity. That is a lot of electricity.

We can do a little better with things called metal organic frameworks (MOFs).These can be made with a high surface energy to absorb CO2 and since they do not form strong chemical bonds the CO2 can be recovered at temperatures in the vicinity of  80 – 100 degrees C, which opens the possibility of using waste heat from power stations. That lowers the energy cost quite a bit. Without the waste heat the energy requirement is still significant, about half that of the amines. The comes the sting – the waste heat approach still leaves about 60% of what was absorbed, so it is not clear the waste heat has saved much. The addition of an extra step is also very expensive.

The CO2 content of effluent gases is between 4 – 15%; for ordinary air it is 0.04%, which makes it very much more difficult to capture. One proposal is to capture CO2 by bubbling air through a solution of potassium hydroxide, and then evaporating off the water and heating the potassium carbonate to decomposition temperature, which happens to be about 1200 degrees C. One might have thought that calcium oxide might be easier, which pyrolyses about 600 degrees C, but what do I know? This pyrolysis takes about 2.4 MWh per tonne of CO2, and if implemented, this pyrolysis route that absorbs CO2 from the air would require about 1.53 TWh of electricity per year for sequestering 1 million t of CO2.

When you need terawatt hours of electricity to run a plant capable of sequestering one million tonne of CO2, and you need to sequester a billion t, it becomes clear that this is going to take an awful lot of energy. That costs a lot money. In the UK, electricity costs between £35 – 65 per MWh, and we have been talking in terms of a million times that per plant. Who pays? Note this scheme has NO income stream; it sells nothing, so we have to assume it will be charged to the taxpayer. Lucky taxpayer!

One small-scale effort in Iceland offers a suggested route. It is not clear how they capture the CO2, but then they dissolve it in water and inject that into basalt, where the carbonic acid reacts with the olivine-type structures to make carbonates, where it is fixed indefinitely. That suggests that provided the concentration of CO2 is high enough, using pressure to dissolve it in water might be sufficient. That would dramatically lower the costs. Of course, the alternative is to crush the basalt and spread it in farmland, instead of lime. My preferred option to remove CO2 from the air is to grow plants. They work for free at the low concentrations. Further, if we select seaweed, we get the added benefit of improving the ecology for marine life. But that requires us to do something with the plants, or the seaweed. Which means more thinking and research. The benefit, though, is the scheme could at least earn revenue. The alternatives are to bankrupt the world or find some other way of solving this problem.

A Plan to Counter Global Warming Must be Possible to Implement

Politicians seem to think that once there is a solution to the problem in theory, the problem is solved so they stop thinking about it. Let us look at a reality. We know we have a problem with global warming and we have to stop burning fossil fuels. The transport sector is a big problem, but electric vehicles will do the trick, and in theory that might be true, but as I have pointed out in previous posts there is this troublesome matter of raw materials. Now the International Energy Agency has brought a little unpleasantness to the table. They have reported that global battery and minerals supply chains need to expand ten-fold to meet the critical needs of 2030 if the plan is to at least maintain schedule. If we take the average size of a major producer as a “standard mine” according to the IEA we need 50 more such lithium mines, 60 more nickel mines, and 17 more cobalt mines operating fully by 2030. Generally speaking, a new mine needs about ten years between starting a feasibility study and serious production. See a problem here? Because of the costs and exposure, you need feasibility studies to ensure that there is sufficient ore where you can’t see, that there is an economic way of processing the ore, and you must have a clear plan on what to do with what to do with minerals you do not want, with materials like arsenates or other undesirables also being present. You also have to build new roads, pipe in water, provide electricity, and do a number of other things to make the mine work that are not directly part of the mine. This does not mean you cannot mine, but it does mean it won’t be quite as easy as some might have you think. We now want our mines not to be environmental disasters. The IEA report notes that ten years, and then adds several more years to get production up to capacity.

The environmental issues are not to be considered as irrelevant. Thus the major deposits of lithium tend to be around the Andes, typically in rather dry areas. Then lithium is obtained by pumping down water, dissolving the salts, then bringing them up and evaporating the brine. Once most of the lithium is obtained, something has to be done with the salty residue, and of course the process needs a lot of water. The very limited water already in some locations is badly needed by the local population and their farms. The salt residues would poison agriculture.

If we consider nickel, one possible method to get more from poorer ores is high-pressure acid leaching. The process uses acid at high temperatures and pressure and end up with nickel at a grade suitable for batteries. But nickel often occurs as a sulphide, which means as a byproduct you get hydrogen sulphide, and a number of other effluents that have to be treated. Additionally, the process requires a lot of heat, which means burning coal or oil. The alternative source to the sulphide deposits, as advocated by the IEA, is laterite, a clayish material that also contains a lot of iron and aluminium oxides. These metals could also be obtained, but at a cost. The estimate of getting nickel by this process is to double the cost of the nickel.

The reason can be seen from the nature of the laterite (https://researchrepository.murdoch.edu.au/id/eprint/4340/1/nickel_laterite_processing.pdf), which is a usually a weathered rock. At the top you have well weathered rock, more a clay, and is red limonite. The iron oxide content (the cause of the red colour) is over 50% while the nickel content is usually less than 0.8% and the cobalt less than 0.1%. Below that is yellow limonite, where the nickel and cobalt oxides double their concentration. Below that we get saprolite/serpentine/garnierite (like serpentine but with enhanced nickel concentration). These can have up to 3% nickel, mainly due to the garnierite, but the serpentine family are silicates, where the ferrous such as in olivine has been removed. The leaching of a serpentine is very difficult simply because silicates are very resistant. Try boiling your average piece of basalt in acid. There are other approaches and for those interested, the link above shows them. However, the main point is that much of the material does not contain nickel. Do y9ou simply dump it, or produce iron at a very much higher cost than usual?

However, the major problems for each are they are all rather energy intensive, and the whole point of this is to reduce greenhouse emissions. The acid leach is very corrosive, and hence maintenance is expensive, while the effluents are troublesome for disposal. The disposal of the magnesium sulphate at sea is harmless, but the other materials with it may not be. Further, if the ore is somewhere like the interior of Australia, even finding water will be difficult.

Of course all these negatives can be overcome, with effort, if we are prepared to pay the price. Now, look around and ask yourself how much effort is going into establishing all those mines that are required? What are the governments doing? The short answer, as far as I can tell, is not much. They leave it to private industry. But private industry will be concerned that their balance sheets can only stand so much speculative expansion. My guess is that 2030 objectives will not be fulfilled.