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.

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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?

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.

Economic Consequences of the Ukraine War

My last post mentioned the USSR collapse. One of the longer term consequences has been this Ukraine war. Currently, there have been problems of shelling of the Zaporizhzhia nuclear plant, and this appears to have happened in that our TV news has shown some of the smashed concrete, etc. The net result is the plant has shut down. Each side accuses the other of doing the shelling, but it seems to me that it had to be the Ukrainians. Russia has troops there, and no military command is going to put up with his side shelling his own troops. However, that is far from the total bad news. So far, Ukraine has been terribly lucky, but such luck cannot last indefinitely. There are consequences outside the actual war itself. The following is a summary of some of what was listed in the August edition of Chemistry World.

The Donbas area is Ukraine’s heavy industry area, and this includes the chemical industry. Recently, Russian air strikes at Sieverierodonetsk hit a nitric acid plant, and we saw images of the nitrogen dioxide gas spewing into the atmosphere.

Apparently, in 2017 Ukrainian shelling was around a chemical plant that contained 7 tonne of chlorine. Had a shell hit a critical tank, that would have been rather awkward. Right now, in the eastern Donbas there is a pipeline almost 700 km long that pipes ammonia. There are approximately 1.5 million people in danger from that pipeline should it burst; exactly how many depends on where it is broken. There are also just under  200,000 t of hazardous waste stored in various places. The question now is, with all this mess generated, in addition to demolished buildings and infrastructure, who will pay what to clean it up? It may or may not be fine for Western countries to use their taxes to produce weapons to give to Ukraine, but cleaning up the mess requires the money to go to Ukraine, not armament-making corporations at home.

The separation of the Donbas has led to many mines being closed, and these have filled with water. This has allowed mercury and sulphuric acid to be leached and then enter the water table. During 2019, a survey of industrial waste was made, and Ukraine apparently stores over 5.4 billion t of industrial waste, about half of which is in the Donbas. Ukraine has presumably inherited a certain amount, together with some of the attitudes, from the old Soviet Union. From experience, their attitude to environmental protection was not their strong point. I recall  one very warm sunny morning going for a walk around Tashkent. I turned a corner and saw rather a lot of rusty buildings, and also, unbelievably, a cloud. How could water droplets form during such a warm dry climate? The answer was fairly clear when I got closer. One slight whiff, and I knew what it was: the building was emitting hydrogen chloride into the atmosphere and the hydrochloric acid droplets were the reason for the rust.

Meanwhile, some more glum news. We all know that the sanctions in response to the Ukraine war has led to a gas shortage. What most people will not realize is what this is doing to the chemical industry. The problem for the chemical industry is that unlike most other industries, other than the very sophisticated, the chemical industry is extremely entangled and interlinked. A given company may make a very large amount of chemical A, which is then sold as a raw material to a number of other companies, who in turn may do the same thing. There are many different factories dependent on the same raw chemical and the material in a given chemical available to the public may have gone through several different steps in several different factories.

An important raw mixture is synthesis gas, which is a mix of carbon monoxide and hydrogen. The hydrogen may be separated and used in steps to make a variety of chemicals, such as ammonia, the base chemical for just about all nitrogen fertilizer, as well as a number of other uses. The synthesis gas is made by heating a mixture of methane gas and water. Further, almost all chemical processing requires heat, and by far the bulk of the heat is produced by burning gas. In Europe, the German government is asking people to cut back on gas usage. Domestic heating can survive simply by lowering the temperature, although how far down one is prepared to go during winter is another question. However, the chemical industry is not so easily handled. Many factories use multiple streams, and it is a simple matter to shut down such a stream, but you cannot easily reduce the amounts going through a stream because the reactions are highly dependent on pressure, and the plant is in a delicate balance between amount processed and heat generated.  A production unit is really only designed to operate one way, and that is continuously with a specific production rate. If you close it down, it may take a week to get it started again, to get the temperature gradients right. One possibility is the complete shutdown of the BASF plant at Ludwigshafen, the biggest chemical complex in the world. The German chemical industry uses about 135 TWhr of gas, or about 15% of the total in the country. The price of such gas has risen by up to a factor of eight since Russia was sanctioned, and more price rises are likely. That means companies have to try to pass on costs, but if they face international competition, that may not be possible. This war has consequences far beyond Ukraine.

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.

Limits to Growth

A little over fifty years ago, the Systems Dynamics group at MIT produced a 200-page book called The Limits to Growth. Their message was, continued economic and population growth would deplete Earth’s resources and lead to global economic collapse by 2070. At the time, this was considered heresy. The journal Nature was scathing (See vol 236, pp 47 – 49, 1972). How could the foundations of industrial civilization, such as coal mining, steel-making, oil production, crop spraying, cause lasting damage? It was accepted that such industries caused pollution, but such effects were considered to be only temporary. At the time computer modelling was looked down upon. This is understandable; at the time computers were quite primitive compared with now, and big computers were only available to the major organizations. I recall four years before that someone doing a chemical bond calculation and coming back from the computer with what looked like a couple of kg of printout. His problem was that his program only produced two answers, depending on what he changed in the code. The answers were zero or infinity. As I remarked, the truth would be somewhere in between.

It is unlikely that any other computer model has made a bigger impact. There are still debates, but it is now clear that our activities have made irreversible environmental effects. As I have also noted in a previous post, there is also significant resource depletion. The elements have not gone anywhere, but that does not help if they are so diluted with other material that we cannot use them. Of course, it is arguable we could with unlimited energy, but we do not have that. The sun effectively produces unlimited energy, but it is too far away; here all it delivers is approximately 1360 W/m^2 at the top of the atmosphere, which is reduced to somewhere between 1000 – 1150 W/m^2 on a surface at right angles to the radiation at the surface. These numbers have to be divided by three for a 24-hr day, assuming no clouds.

The obvious problem for people is economic growth. Some people assume that economic growth can continue if we adopt technology much faster, particularly employing more renewable energy. Others argue we have to abandon the idea of growth. Was living as per we did in, say, 2016 that bad? One problem is that politicians need votes, and to get them they want to raise GDP. Thus if there is a choice of what to do, politicians will go for that which produces the most jobs. Excessive spending on the military increases jobs; corresponding spending on healthcare does not, but which is the more useful?

One analysis (Rockström et al. 2009, Nature 461: 472 – 475) argued there were boundaries. If we stayed within these the planet would adjust and correct our behaviour, but as we approached those boundaries (i.e. too much of something is being emitted) the planet may respond in a non-linear and often in an abrupt way. Most of these thresholds depend on one, or sometimes more, variables. They suggest ten such processes have such boundaries, three of which, biodiversity loss, climate change, the nitrogen cycle, are already exceeded, while a fourth, the phosphorus cycle is close to the breaking point and a fifth, ocean acidification is troublesome. Two more, chemical pollution and atmospheric aerosol loading were not quantified. Three, fresh water use, land use, and ozone depletion are considered to be under control.

The last time the poles were essentially ice-free the CO2 levels were approximately 450 ppm. As can be seen from my last post, exceeding that seems inevitable without drastic action. For biodiversity, extinctions are currently about 100 – 1000 times greater than natural. Biodiversity is very important to maintain the resilience of the system. The production of nitrogen fertilizer and the cultivation of legumes convert around 120 million t/a of nitrogen, which is more than the combined efforts of all Earth’s terrestrial processes. This ends up as pollution, it erodes resilience of some of the plant life, and it sends nitrous oxide into the atmosphere, and this makes a major contribution to greenhouse forcing. Excess nitrogen fertiliser leads to turbid waterways, lakes, etc, and sometimes pronounced algal blooms. About 20 Mt of phosphorus is mined each year, and about half of this finds its way into oceans. This is around eight times the natural erosion rate. When critical levels of phosphate enter the oceans, large scale anoxic events occur, which can lead to mass extinctions of marine life. The authors conclude that as long as we do not exceed the thresholds, we can pursue long-term economic and social development. Our problem is, we are crossing some.

Will We Do Anything To Stop Global Warming?

There is an interesting review on climate change (Matthews & Wynes, 2022, Science 376: 1404 – 1409). One point that comes up early is how did this sneak up on us? If you look at the graph on global temperatures, you will see that the summers in the 1940s were unusually hot, and the winters in the 1960 – 1980 period were unusually cool, with the net result that people living between 1940 – 1985 could be excused for thinking in terms of extremes instead of averages that the climate was fairly stable. As you will recall, at 1990 there was a major conference on climate change, and by 1992 goals were set to reduce emissions. It is just after this that temperatures have really started rising. In other words, once we “promised” to do something about it, we didn’t. At 1960 the CO2 levels in the atmosphere were about 320 ppm; by 1990 the CO2 levels were about 365 ppm, and at 2022 they are about 420 ppm. The levels of CO2 emissions have accelerated following the treaty in which much of the world undertook to reduce them. Therein lies out first problem. We are not reducing emissions; we are increasing them, even though we promised to do the opposite. (There was a small reduction in 2019-2020 as a result of the Covid lockdowns, but that has passed.) In short, our political promises are also based on hot air.

The current warming rate is approximately a quarter of a degree Centigrade per decade, which means that since we are now about 1.25 degrees warmer than the set 1850 baseline, we shall hit the 1.5 degrees warming somewhere just after 2030. Since that was the 1990 target not to be exceeded, failure seems inevitable. According to the models, to hold the temperature to 1.5 degrees C above our baseline we must not emit more than 360 Gt (billion tonne) of CO2. The IPCC considers we shall emit somewhere between 400 -650 Gt of CO2 before we get carbon neutral (and that assumes all governments actually follow up on their stated plans.) What we see is that current national targets are simply inadequate, always assuming they are kept. Unfortunately, there is a second problem: there are other greenhouse gases and some are persistent. The agricultural sector emits nitrous oxide, while industry emits a range of materials like sulphur hexafluoride, which may not be there in great quantity but it is reputedly 22,800 times more effective at trapping infrared radiation than CO2, and it stays in the atmosphere for approximately 3,200 years. These minor components cannot be ignored, and annual production is estimated at about 10,000 t/a. It is mainly used in electrical equipment, from whence it leaks.

Current infrastructure, such as electricity generators, industrial plant, ships, aircraft and land transport vehicles all have predictable lifetimes and emissions. These exceed that required to pass the 1.5 degree C barrier already unless some other mitigation occurs. Thus, the power stations already built will emit 846 Gt CO2, which is over twice our allowance. People are not going to abandon their cars. Another very important form of inertia is socio-political. To achieve the target, most fossil fuel has to stay in the ground, but politicians keep encouraging the development of new extraction. The average voter is also unhappy to see major tax increases to fund things that will strongly and adversely affect his way of life.

One way out might be carbon capture. The idea of absorbing CO2 from the atmosphere and burying it may seem attractive, but how is it done, at what cost in terms of money and energy required to do it, and who pays for it? Planting trees is a more acceptable concept. In New Zealand there is quite a bit of land that was logged by the early settlers, but has turned out to be rather indifferent farm land. The problem with knowing whether this is a potential solution or not is that it is impossible to know how much of such land can be planted, given that a lot is privately owned. However, planting trees is realistically something that could help, even if it does not solve the problem.

The article seems to feel that the solution must include actions such as lifestyle changes (carless days, reduced speed limits, reduced travel, a reduction of meat eating). My feeling is this would be a very difficult sell in a democracy, and it is not exactly encouraging to persuade some to purchase electric vehicles then be told they cannot use them. The article cites the need for urgency, and ignores the fact that we have had thirty years where governments have essentially ignored the problem. Even worse, the general public will not be impressed to find they are required to do something that adversely affects their lifestyle, only to find that a number of other countries have no interest in subjecting their citizens to such restrictions. The problem is no country can stop this disaster from happening; we all have to participate. But that does not mean we all have to give up our lifestyles, just to ensure that politicians can get away with their inability to get things done. In my opinion, society has to make changes, but they do not have to give up a reasonable lifestyle. We merely need to use our heads for something better than holding up a hat. And to show that we probably won’t succeed, the US Supreme Court has made another 6:3 ruling that appears to inhibit the US Federal Government from forcing certain states to reduce emissions. We shall cook. Yes, this might be a constitutional technicality that Congress could clear up easily, but who expects the current Congress to do anything helpful for civilization?

Energy Sustainability

Sustainability is the buzzword. Our society must use solar energy, lithium-ion batteries, etc to save the planet, at least that is what they say. But have they done their sums?. Lost in this debate is the fact that many of the technologies use relatively difficult to obtain elements. In a previous post I argued that battery technology was in trouble because there is a shortage of cobalt, required to make the cathode work for a reasonable number of cycles. Others argue that we could obtain sufficient elements. But if we are going to be sustainable, we have to be sustainable for an indefinite length of time, and mining is not sustainable; you can only dig up the ore once. Of course, there are plenty of elements left. There is more gold in the sea than has ever been mined; the problem is that it is too dilute. Similarly, most elements are present in a lump of basalt; just not much of anything useful and it is extremely difficult to get it out. The original copper mines of Cyprus, where even lumps of copper could occasionally be found, are all worked out, at least to the extent that mining is no longer profitable there.

The answer is to recycle, right? Well, according to an article [Charpentier Poncelet, A. et al. Nature Sustain. https://doi.org/10.1038/s41893-022- 00895-8 (2022)] there are troubles. The problem is that even if we recycle, every time we do something we lose some of the metal. Losses here refer to material emitted into the environment, stored in waste-disposal facilities, or diluted in material where the specific characteristics of the elements are no longer required. The authors define a lifetime as the average duration of their use, from mining through to being entirely lost. As with any such definition-dependent study, there will be some points where you disagree.

The first loss for many elements lies in the production state. Quite often it is only economical to obtain one or two elements, and the remaining minor components of the ore disappear in slag. These losses are mainly important for specialty elements. Production losses account for 30% of rare earth metals, 50% for cobalt, 70% for indium, and greater than 95% for arsenic, gallium, germanium, hafnium, selenium and tellurium. So most of those elements critical for certain electronic and photo-electric effects are simply thrown out. We are a wasteful lot.

Manufacturing and use incur very few losses. There are some, but because materials are purified ready for use, pieces that are not immediately used can be remelted and used. There are exceptions. 80% of barium is lost through use; it is used in drilling muds.

The largest losses come from the waste management and recycling stage. Metals undergoing multiple life cycles are still lost this way; it just takes longer to lose them. Recycling losses occur when the metal accumulates in a dust (zinc) or slag(e.g. chromium or vanadium), or get lost in another stream, thus copper is prone to dissolve in an iron stream. Longest lifetimes occur for non-ferrous metals (8 to 76 years) precious metals (4 to 192 years), and ferrous metals (8 to 154 years). The longest lifetimes are for gold and iron.

Now for the problem areas. Lithium has a life-cycle use of 7 years, then it is all gone. But lithium-ion batteries last about this long, which suggests that as yet (if these data are correct) there is very little real recycling of lithium. Elements like gallium and tellurium last less than a year, while indium manages a year. Before you protest that most of the indium goes into swipeable mobile phone screens and mobile phones last longer than a year, at least for some of us, remember that losses occur through being discarded at the mining stage, where the miner/processor can’t be bothered. Of the fifteen metals most lost during mining/processing, thirteen are critical for sustainable energy, such as cobalt (lithium-ion batteries), neodymium (permanent magnets), indium, gallium, germanium, selenium and tellurium (solar cells) and scandium (solid oxide fuel cells). If we look at the recycled content of “new material” lithium is less than 1% as is indium. Gallium and tellurium are seemingly not recycled. Why are they not recycled? Metals that are recycled tend to be like iron, aluminium, the precious metals and copper. It is reasonably easy to find uses for them where purity is not critical. Recycling and purifying most of the others requires technical skill and significant investment. If we think of lithium-ion batteries, the lithium reacts with water, and if it starts burning it is unlikely to be put out. Some items may have over a dozen elements, and some are highly toxic, and not to be in the hands of the amateur. What we see happening is that the “easy” metals are recycled by organizations that are really low-technology organizations. It is not an area attractive to the highly skilled because the economic risk/return is just not worth it, while the less-skilled simply cannot do it safely.

Seaweed and Climate Change

A happy and prosperous New Year to you all. The Great New Zealand Summer Vacation is coming to an end, so I have made an attempt at returning to normality. I hope all is well with you all.

Last year a paper in Nature Communications (https://doi.org/10.1038/s41467-021-22837-2) caught my eye for two reasons. First, it was so littered with similar abbreviations I found it difficult to follow. The second was that they seemed to conclude the idea of growing seaweed to absorb carbon dioxide would not work, but  they seemed to refuse to consider any option by which it might work. We know that much of seaweed biomass arises from photo-fixing CO2, as does biomass from all other plants. So there are problems. There were also problems ten thousand years ago for our ancestors in Anatolia or in the so-called fertile crescent wanting to grow some of those slightly bulky grass seeds for food. They addressed those problems and got to work. It might have been slow, but soon they had the start of a wheat industry.

So, what was the problem? The paper considered the Sargasso Sea as an example of massive seaweed growth. One of the first objections the paper presented was that the old seaweed fronds get coated with life forms such as bryozoans that have calcium carbonate coatings. They then state that by making this solid lime (Ca⁺⁺ + CO3^— -> CaCO3, a solid) it releases CO2 by reducing seawater alkalinity. The assertion was from a reference, and no evidence was supplied that it is true in the Sargasso. What this does is to deflect the obvious: for each molecule of lime formed, a molecule of CO2 was removed from the environment, not added to it as seemingly claimed. Associated with this is the statement that the lime shields the fronds from sunlight and hence reduces photosynthesis. Can we do anything about this? We could try harvesting the old fronds and keep growing new ones. Further, just as our ancestors found that by careful management they could improve the grain size (wild wheat is not very impressive) we could “weed” to improve the quality of the stock.

I don’t get the next criticism. While calcification on seaweed was bad because it liberated CO2 (so they say) they then go on to say that growing seaweed reduces the phytoplankton, and then the calcification of that gets reduced, which liberates more CO2. Here we have increased calcification and decreased calcification both increase CO2. Really?

Another criticism is that the seaweeds let out other dissolved carbon, which is not particulate carbon. That is true, but so what? The dissolved sugars are not acidic. Microalgae will gobble them up, but again, so what?

The next criticism is if we manage to reduce the CO2 levels in the ocean, we cannot calculate what is going on, and the atmosphere may not be able to replenish the levels for a up to a hundred years. Given the turbulence during storms I find this hard to believe, but if it is true, again, so what? We are busy saving the ocean food chains. Ocean acidification is on the verge of wiping out all shellfish that rely on forming aragonite for their shells. Reducing that acidity should be a good thing.

They then criticise the proposal because growing forests on land reduces the albedo, and by making the land darker, makes the locality warmer. They then say the Sargasso floating seaweed increases the albedo of that part of the ocean, and hence reflects more light back to space, which reduces heat generation. Surely this is good? But wait. They then point out that other proposals have seaweed growing in deep water and this won’t happen. In other words, some aspect of some completely different proposal is a reason not to proceed with this one. Then they conclude by saying they need more money to get more detailed information. I agree more detailed information would be helpful, but they should acknowledge possible solutions to their problems. Thus ocean fertilization and harvesting mature seaweed could change their conclusions completely. I suspect the problem is they want to measure things, possibly remotely, but they do not want to actually do things, which involves a lot more effort, specifically on location. But for me, the real annoyance is that everyone by now knows that global warming is a problem. Growing seaweed might help solve that problem. We need to know whether it will contribute to a solution or merely transfer the problem. They may not have the answers, but they at least should identify the questions that need answers.

What to do about Climate Change

As noted in my previous post, the IPCC report on climate change is out. If you look at the technical report, it starts with pages of corrections. I would have thought that in these days the use of a word processor could permit the changes to be made immediately, but what do I know? Anyway, what are the conclusions? As far as I can make out, they have spent an enormous effort measuring greenhouse gas emissions and modelling, and have concluded that greenhouse gases are the cause of our problem and if we stopped emitting right now, totally, things would not get appreciably worse than they are now over the next century. As far as I can make out, that is it. They argue that CO2 emissions give a linear effect and for every trillion tonnes emitted, temperatures will rise by 0.45 Centigrade degrees, with a fairly high error margin. So we have to stop emitting.

The problem is, can we? In NZ we have a very high fraction of our electricity from renewable sources and we recently had a night of brown-outs in one region. It was the coldest night of the year, there was a storm over most of the country, but oddly enough there was hardly any wind at a wind farm. A large hydro station went out as well because the storm blew weeds into an intake and the station had to shut down and clean it out. The point is that when electricity generation is a commercial venture, it is not in the generating companies’ interests to have a whole lot of spare capacity and it make no sense to tear down what is working well and making money to spend a lot replacing it. So, the policy of using what we have means we are stuck where we are. China has announced, according to our news, that its coal-fired power stations will maximise and plateau their output of CO2 in about ten years. We have no chance of zero emissions in the foreseeable future. Politicians and environmentalists can dream on but there is too much inertia in an economy. Like a battleship steering straight for the wharf, the inevitable will happen.

Is there a solution? My opinion is, if you have to persist in reducing the heat being radiated to space, the best option is to stop letting so much energy from the sun into the system. The simplest experiment I can think of is to put huge amounts of finely dispersed white material, like the silica a volcano puts up, over the North Polar regions each summer to reflect sunlight back to space. If we can stop as much winter ice melting, we would be on the way to stop the potential overturn of the Gulf Stream and stop the Northern Siberian methane emissions. Just maybe this would also encourage more snow in the winter as the dust falls out.

Then obvious question is, how permanent would such a dispersion be? The short answer is, I don’t know, and it may be difficult to predict because of what is called the Arctic oscillation. When that is in a positive phase it appears that winds tend to circulate over the poles, so it may be possible to maintain dust over summer. It is less clear what happens in the negative phase. However, either way someone needs to calculate how much light has to be blocked to stop the Arctic (and Antarctic) warming. Maybe such a scheme would not be practical, but unless we at least make an effort to find out, we are in trouble.

This raises the question of who pays? In my opinion, every country with a port benefits if we can stop major sea level rising, so all should. Of course, we shall find that not all are cooperative. A further problem is that the outcome is somewhat unpredictable. The dust only has to last during the late spring and summer, because the objective is to reflect sunlight. For the period when the sun is absent it is irrelevant. We would also have to be sure the dust was not hazardous to health but we have lived through volcanic eruptions that have caused major lowering of the temperature world-wide so there will be suitable material.

There will always be some who lose on the deal. The suggestion of putting the dust over the Arctic would make the weather less pleasant in Murmansk, Fairbanks, Yukon, etc, but it would only return it to what it used to be. It is less clear what it would do elsewhere. If the arctic became colder, presumably there would be colder winter storms in more temperate regions. However, it might be better that we manage the climate than then planet does, thus if the Gulf Stream went, Europe would suffer both rising sea levels and temperatures and weather more like that of Kerguelen. In my opinion, it is worth trying.

But what is the betting any proposal for geoengineering has no show of getting off the ground? The politically correct want to solve the problem by everyone giving up something, they have not done the sums to estimate the consequences, and worse, some will give things up but enough won’t so that such sacrifices will be totally ineffective. We have the tragedy of the commons: if some are not going to cooperate and the scheme hence must fail, why should you even try? We need to find ways of reducing emissions other than by stopping an activity, as opposed to the emission.