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?

Advertisement

Belief in Science

I recently read something from a libertarian who accused people who “believe in science” as followers of a religion. The first point was, how can you so believe when you find well-credentialled scientists on both sides of an issue? The writer claimed that certain people may prefer people do not know this, but dissenting experts exist on many scientific questions that some pronounce as settled by a consensus. It claims credentialled maverick are often maligned as having been corrupted by industry, while scientists who view the established position are pure and incorruptible. So what do you think of that?

One comment lies in “well-credentialled” and “both sides of the issue”. By the time I started science in earnest, so to speak, Sir Richard Doll had produced a study showing heavy smoking greatly increased the risk of lung cancer. At the time, epidemiology was a “fringe” part of medicine but the statistics showed the truth. Naturally, there were people who questioned it, but I recall a review that showed that cigarette smoke contained a large number of chemicals that could be called carcinogens. One, 3,4-benzopyrene, was so active it guaranteed a cancer if a smear was applied to a certain strain of mice. Yes, they were particularly susceptible, but the point was obvious. Cigarette smoke contains a number of carcinogenic chemicals. Yet for years papers were produced that showed cigarette smoke was “harmless” and something else must be doing it. These were published in fringe journals and while the authors had credentials, they were being paid by the tobacco industry. So much for “both sides of the issue”.

A major criticism that comes to my mind is that the author does not understand what he is talking about. Science is not a collection of facts; it is a methodology for attempting to obtain the truth. Like any other activity, it does not always work well, but in principle you do not accept a statement based on the reputation of the speaker; that is the logic fallacy ad verecundiam. Unfortunately, what actually happens is so many are just plain lazy so they do not seek to check but rather accept it. Of course, if it is not important to you the consensus usually makes a lot of sense because you have not examined the details. Further, you accept it because you are only marginally interested. If someone says that a vaccine has passed a clinical trial in which x thousand people took part, there were no adverse effects and the vaccine worked, I take their word. The alternative is to check everything yourself, but you know that a procedure is in place where independent people have checked the statements, so I accept they are true. Science works by recording what we know and building on it. If there was a huge conspiracy to hide some real problems with a vaccine, the conspirators would eventually be found out, and an extended length of time would be spent in a rather uncomfortable cell.

Another criticism was that the “truth” comes down from a set of anointed scientists, and dissenters can be ignored because they are outside the group that matters. There is an element of truth in this. The anointed always get funding, and they get to peer review other funding applications. Dissent from the anointed means it is far more difficult to get funding. Further, the number of citations and publications you get means more funding. This leads to gaming the system, but such gaming cannot work with a dissenter. Sometimes, up to fifty scientists may agree to be authors on a number of papers (If you have fifty, they should produce fifty times the output of one.) But nobody counts the degree of share, and worse, they can keep citing all the papers within the set when one is being written, so automatically the number of citations jumps. Nobody notices they are self-citations or looks to see if they are relevant. That may seem unfair to others, but with money at stake, scientists also do what they can. This funding anomaly does lead to a group consensus.

Another example lies in climate change. Whether there is consensus is irrelevant; the question is, is there a definitive observation? I concede that initially I was suspicious, largely because there was a lot of modelling but not many facts. The theory was known, but the models ignored too many variables, and nothing seemed to have happened to the climate. The theory suggested there was an effect, but at first there was not much evidence for it. Then the evidence of warmer times started to come, but against that is climate has always changed. What was needed was a definitive set of measurements, and eventually they came (Lyman, J. M. and 7 others, 2010. Nature 465: 334-337.) What this showed was between 1993 and 2008 there was been an increase in the heat power delivered to the oceans of 0.64 w.m^-2. That may not seem to be much, but multiply that across the area of oceans and you will see the planet is getting a very substantial net power input over a long period of time. We are cooking ourselves, but like the proverbial frog, we seem not to notice enough to do much about it.

One final comment. I wrote a chapter on climate change in my first ebook, which was about how to form theories, and which not only included the reasons why we should recognize the effect is real, but also I listed some previous technologies that could go some way towards reducing our dependencies on fossil fuels. These were all published or recorded in various archives, and one of the interesting things about this is that none of the recommended technologies have been proposed to be used. It is almost as if work done in the 1970-80s might as well not have been carried out. So what seemed to be “state of the art” then is now forgotten. There are problems in dealing with scientific issues and getting value from them, but group consensus is only temporary, and anything that can be forgotten probably will be. You don’t get science funding resurrecting the wheel, but you get somewhere. The question is, do we really want to get somewhere?

Biofuels to Power Transport

No sooner do I post something than someone says something to contradict the post. In this case, immediately after the last post, an airline came out and said it would be zero carbon by some time in the not-too-distant future. They talked about, amongst other things, hydrogen. There is no doubt hydrogen could power an aircraft, as it also powers rockets that go into space. That is liquid hydrogen, and once the craft takes off, it burns for a matter of minutes. I still think it would be very risky for aircraft to try to hold the pressures that could be generated for hours. If you do contain it, the extra weight and volume occupied would make such travel extremely expensive, while sitting above a tank of hydrogen is risky.

Hydrocarbons make by far the best aircraft fuel, and one alternative source of them is from biomass. I should caution that I have been working in this area of scientific research on and off for decades (more off than on because of the need to earn money.) With that caveat, I ask you to consider the following:

C6H12O6  ->  2 CO2 +2H2O + “C4H8”

That is idealized, but the message is a molecule of glucose (from water plus cellulose) can give two molecules each of CO2 and water, plus two thirds of the starting carbon as a hydrocarbon, which would be useful as a fuel. If you were to add enough hydrogen to convert the CO2 to a fuel you get more fuel. Actually, you do not need much hydrogen because we usually get quite a few aromatics, thus if we took two “C4H8” and make xylene or ethyl benzene (both products that are made in simple liquefactions) these total C8H10, which gives us a surplus of three H2 molecules. The point here is that in each of these cases we could imagine the energy coming from solar, but if you use biomass, much of the energy is collected for you by nature. Of course, if you take the oxygen out as water you are left with carbon. In practice there are a lot of options, and what you get tends to depend on how you do it. Biomass also contains lignin, which is a phenolic material. This is much richer in hydrocarbon material, but also it is much harder to remove the oxygen.

In my opinion, there are four basic approaches to making hydrocarbon fuels from biomass. The first, which everyone refers to, is pyrolysis. You heat the biomass, you get a lot of charcoal, but you also get liquids. These still tend to have a lot of oxygen in them, and I do not approve of this because the yields of anything useful are too low unless you want to make charcoal, or carbon, say for metal refining, steel making, electrodes for batteries, etc. There is an exception to that statement, but that needs a further post.

The second is to gasify the biomass, preferably by forcing oxygen into it and partially burning it. This gives you what chemists call synthesis gas, and you can make fuels through a further process called the Fischer-Tropsch process. Germany used that during the war, and Sasol in South Africa Sasol, but in both cases coal was the source of carbon. Biomass would work, and in the 1970s Union Carbide built such a gasifier, but that came to nothing when the oil price collapsed.

The third is high-pressure hydrogenation. The biomass is slurried in oil and heated to something over 400 degrees Centigrade in then presence of a nickel catalyst and hydrogen. A good quality oil is obtained, and in the 1980s there was a proposal to use the refuse of the town of Worcester, Mass. to operate a 50 t/d plant. Again, this came to nothing when the price of oil slumped.

The fourth is hydrothermal liquefaction. Again, what you get depends on what you put in but basically there are two main fractions from woody biomass: hydrocarbons and phenolics. The phenolics (which includes aromatic ethers) need to be hydrogenated, but the hydrocarbons are directly usable, with distillation. The petrol fraction is a high octane, and the heavier hydrocarbons qualify as very high-quality jet fuel. If you use microalgae or animal residues, you also end up with a high cetane diesel cut, and nitrogenous chemicals. Of particular interest from the point of view of jet fuel, in New Zealand they once planted Pinus Radiata which grew very quickly, and had up to 15% terpene content, most of which would make excellent jet fuel, but to improve the quality of the wood, they bred the terpenes more or less out of the trees.

The point of this is that growing biomass could help remove carbon dioxide from the atmosphere and make the fuels needed to keep a realistic number of heritage cars on the road and power long-distance air transport, while being carbon neutral. This needs plenty of engineering development, but in the long run it may be a lot cheaper than just throwing everything we have away and then finding we can’t replace it because there are shortages of elements.

The Case for Hydrogen in Transport

In the last post I looked at the problem of generating electricity, and found that one of the problems is demand smoothing One approach to this is to look at the transport problem, the other major energy demand system. Currently we fill our tanks with petroleum derived products, and everything is set for that. However, battery-powered cars would remove the need for petrol, and if they were charged overnight, they would help this smoothing problem. The biggest single problem is that this cannot be done because there is not enough of some of the necessary elements to make it work. Poorer quality batteries could be made, but there is another possibility: the fuel cell.

The idea is simple. When electricity is not in high demand, the surplus is used to electrolyse water to hydrogen and oxygen. The hydrogen is stored, and when introduced to a fuel cell it burns to make water while generating electricity. Superficially, this is ideal, but there are problems. One is similar to the battery – the electrodes tend to be made of platinum, and platinum is neither cheap nor common. However, new electrodes may solve this problem. Platinum has the advantage that it is very unreactive, but the periodic servicing of the cell and the replacing of electrodes is realistic, and of course recycling can be carried out because unlike the battery, it would be possible to merely recycle the electrodes. (We could also use pressurised hydrogen in an internal combustion engine, with serious redesign, but the efficiency is simply too low.)

One major problem is storing the hydrogen. If we store it as a gas, very high pressures are needed to get a realistic mass to volume ratio, and hydrogen embrittles metals, so the tanks, etc., may need servicing as well. We could store it as a liquid, but the boiling point is -259 ^oC. Carting this stuff around would be a challenge, and to make matters worse, hydrogen occurs in two forms, ortho and para, which arise because the nuclear spins can be either aligned or not. Because the molecule is so small there is an energy difference between these, and the equilibrium ratio is different at liquid temperatures to room temperatures. The mix will slowly re-equilibrate at the low temperature, give off heat, boil off some hydrogen, and increase the pressure. This is less of a problem if you have a major user, because surplus pressure is relieved when hydrogen is drawn off for use, and if there is a good flow-through, no problem. It may be a problem if hydrogen is being shipped around.

The obvious alternative is not to ship it around, but ship the electricity instead. In such a scenario for smaller users, such as cars, the hydrogen is generated at the service station, stored under pressure, and more is generated to maintain the pressure. That would require a rather large tank, but it is doable. Toyota apparently think the problem can be overcome because they are now marketing the Mirai, a car powered by hydrogen fuel cells. Again, the take-up may be limited to fleet operators, who send the vehicles out of central sites. Apparently, the range is 500 km and it uses 4.6 kg of hydrogen. Hydrogen is the smallest atom so low weight is easy, except the vehicle will have a lot of weight and volume tied up with the gas pressurized storage. The question then is, how many fuel stations will have this very large hydrogen storage? If you are running a vehicle fleet or buses around the city, then your staff can refill as well, which gets them to and from work, but the vehicle will not be much use for holidays unless there are a lot of such stations.

Another possible use is in aircraft, but I don’t see that, except maybe small short-haul flights driven by electric motors with propellors. Hydrogen would burn well enough, but the secret of hydrocarbons for aircraft is they have a good energy density and they store the liquids in the wings. The tanks required to hold hydrogen would add so much weight to the wings they might fall off. If the main hull is used, where do the passengers and freight go? Another possibility is to power ships. Now you would have to use liquid hydrogen, which would require extremely powerful refrigeration. That is unlikely to be economic compared with nuclear propulsion that we have now.

The real problem is not so much how do you power a ship, or anything else for that matter, but rather what do you do with the current fleet? There are approximately 1.4 billion motor vehicles in the world and they run on oil. Let us say that in a hundred years everyone will use fuel cell-driven cars, say. What do we do in the meantime? Here, the cheapest new electric car costs about three times the cost of the cheapest petrol driven car. Trade vans and larger vehicles can come down to about 1.5 times the price, in part due to tax differences. But you may have noticed that government debt has become somewhat large of late, due to the printing of large amounts of money that governments have promptly spent. That sort of encouragement will probably be limited in the future, particularly as a consequence of shortages arising from sanctions. In terms of cost, I rather think that many people will be hanging on to their petrol-powered vehicles, even if the price of fuel increases, because the difference in the price of fuel is still a few tens of dollars a week tops, whereas discarding the vehicle and buying a new electric one involves tens of thousands of dollars, and with the current general price increases, most people will not have those spare dollars to throw away. Accordingly, in my opinion we should focus some attention on finding an alternative to fossil fuels to power our heritage fleet.

“Green” Electricity

Before thinking about how to replace fossil fuels for electricity, we need to look at how the power demand varies through the day. Not unexpectedly, this varies depending on where you live, but if you take various parts of the US as an example of industrialized usage, there is a baseline that involves minimal usage at about 0500 hrs, and that baseline varies by up to 30% seasonally. The difference between day and night can vary by up to 60%, the biggest variation is in hot summer and is due to the use of air conditioning. This means there is a huge difference between peak demand and minimum demand, which in turn means that difference has to be supplied by generation that can be turned on and off. The big thermal plants do not turn on and off easily. You can run the plant without producing electricity, but now you are simply burning fuel for no purpose.

The most responsive generators are the gas turbine and hydroelectricity. Hydro is an obvious “green” source for load smoothing; you simply shut the gate, save water, and stop generating, but most suitable hydro sites are already used. Wind power is also useful; you simply let wind pass if you do not want power, but it runs into trouble when you need power and there is no wind. Solar means you charge batteries during the day and used the power later, but in a previous post I showed it is impossible to make enough batteries to power our vehicle fleet, so how do we make an even greater supply of batteries? A further alternative is to run your base load near maximum usage, and use the surplus to make something like hydrogen when it is not needed. More on hydrogen in a later post.

The “inconvenient truth” for some is the only general major base load provider to replace coal and gas for electricity generation is nuclear. Unfortunately, nuclear has a bad press. Other downsides include, currently, it is too expensive. Most people think it is too dangerous and it is too likely to leak radiation. Actually, the smoke from coal combustion also is cancer inducing to lungs, while in the US there are around 13,000 premature deaths per year due to coal, and 23,000 annually in Europe. Coal is nowhere nearly as safe as people think. So far, nuclear power has a death rate of 0.07 deaths per terawatt-hour of electricity, or about 1 death per 14 years. That figure is enhanced substantially due to stupidity at Chernobyl. Fukushima has 1 death attributed to it, although there are claims that the stresses of it on those who had to move caused a further 2,200. Up to 2004 (18 years later) 78 died from Chernobyl. This is not good, but it is avoidable.

Current reserves of uranium total 5.3 million tonne, about a third of which are in Australia. However, only about 36,000 t of that is U235, which is what is fissile, and has to be enriched. The depleted uranium waste from the enrichment process goes into armour-piercing military rounds. What happens in most nuclear power stations is the enriched uranium rods generate heat, then have to be taken away to be reprocessed, which involves removing the plutonium for weapons. A long time ago, when I was at school, we had a visiting energy expert who told us that in the future the world would develop breeder reactors, and the enriched uranium would produce more fuel in the form of plutonium than it consumed in making electricity, The need to feed the military complex means that did not happen.

What is possible is a new generation of reactor, based on the fuel being dissolved in molten salt. The reactor is now at thermal equilibrium so it is impossible to have a melt-down – there is nothing to melt. The one catch is the issue of corrosion. That can undoubtedly be dealt with, but we have yet to learn the real long-term issues. China is currently testing one demonstration plant, and it is designed to simply provide the boiling pressurized water to run an existing power plant. The idea is simply the coal-firing is removed, this heat source is plugged in and everything else continues working. As the U238 gets converted to plutonium, it also fissions and generates heat to make electricity. What the surplus neutrons in the reactor do is also to burn “hot” isotopes, so the waste disposal problems are far less. Finally, once going, it can also take thorium as a fuel, and there is far more thorium in the world. Simple fission could keep us going for centuries.

Arguably, nuclear is not “green”. My argument is we either use it or not, but it alone has any chance of providing the levels of electricity we need and replace fossil fuel burning.

Ultimately, fusion power would solve all our energy problems. There is only one problem with it: we do not know how to make it work. There is also one general problem. To change our ways, we shall have to spend a very large amount of money, and basically replace about two thirds of our existing electricity generating infrastructure. The alternative is to do nothing and then rebuild all our major coastal cities when the ice sheets collapse. That is also expensive. We have a choice, but unfortunately our politicians seem to want to do nothing and leave the problem for our grandchildren.

The IPCC Orders Action

The Intergovernmental Panel on Climate Change has produced Part 3 of a report, and with only about 2900 pages, that has one stark message: we need aggressive action to curb greenhouse gas emission AND we need aggressive action to absorb CO2 from the atmosphere, and the action must start now, not some indefinite time in the future. As I recall, this problem was highlighted thirty years ago, and in that thirty years, emissions have increased. There was not even a hint of a reduction. To give some idea of how seriously some take this matter, Germany closed down its nuclear power plants, and now it threatens not to use Russian gas, but instead burn lignite. We cannot do much worse than that can we?

Maybe we can, and maybe we are. According to an article by Lawrence et al. (Front. For. Glob. Change https://doi.org/10.3389/ffgc.2022.756115 (2022) tropical rain forests not only secrete carbon and take it out of circulation, saving around 0.5 of a degree C, but they also physically cool the planet by a further 0.5 degrees C. What the trees do is to emit much humidity from their leaves, with the result that they cool themselves (similar to sweating) and this humidity creates clouds, which reflect sunlight back to space. This is the sort of a geo-engineering proposal often made, but the trees do it for free. So, what are we doing? Why, cutting down the rain forests. Apparently a third has been removed, and another third has been heavily logged so it is not as functional as it should be. We are supposed to be trying to hold the temperatures to an increase of no more than 1.5 degrees C, we are nearly there already, so do we really need another degree of heating added in for no good reason?

According to the IPCC, carbon emissions will have to decline rapidly after 2025, halve by 2030, and hit “net zero” by the early 2050s. Given current efforts, a warming of 3 degrees is forecast. Emissions from existing and planned projects already exceed the allowable carbon budget. But even going to zero emissions will not suffice in the short term. Nations also need to extract carbon dioxide from the atmosphere.

So, what can we do? First, consider the problem. For our electricity, which has a little under 750 GW global capacity, wind power provides a little over 6%; solar provides a little over 2%, hydropower about 16%, nuclear about 10%. For fuels, earth consumes about 3.8 trillion cubic meters of natural gas, 35.4 billion barrels of oil, and 8.5 billion t of coal a year. Why we have a problem should be clear. Currently, about 2/3 of our electricity comes from burning fossil fuel. Worse, you don’t build a coal-fired power station today and turn it off tomorrow. Wind turbines need solid support. Making a tonne of cement produces roughly 800 kg of CO2, making a tonne of steel releases 1.85 t of CO2; combined they sum to about 16% of the world’s CO2 production. Wind power might be “green” but look at the CO2 emitted making and installing the equipment. Solar is free, but the demand for electricity is when solar is weak or non-existent, so massive storage is required, and that gets expensive, both in terms of money and in CO2 emissions for making the batteries. The point is, all new infrastructure is going to involve a lot of CO2 emissions before any energy is generated.

Transport is a particularly difficult problem. I think it is a common problem, but where I live the cities expanded significantly after WW 2, and they expanded with the automobile in mind. The net result is it is most people get around by car. Most people have access to a car, and that is petrol driven. The electric vehicle that might replace the petrol-driven car costs (here, at least) over twice that of the petrol driven car and you cannot really convert them. The reason is the electric vehicle needs a huge mass of batteries to have a useful driving range. Further, as I pointed out in a previous post, we cannot have everyone driving electric cars because we do not have the cobalt to make the batteries, and we still need ships and aircraft, which use a rather small fraction of the oil cut. We have to do something with the rest of the fuel cut. You may have noticed that large electricity production above and how so much comes from fossil fuels. Transport uses about 25% of the total energy production. That means to convert transport to electricity, we need to expand electricity generation by about another 250 GW. That is easy to write down, but just think of all the CO2 emitted by making the concrete and steel to build the power stations. Our current wind power would have to expand by a factor of 5.5 and we have to hope there are no still days. Of course, you may legitimately argue that if we charged batteries at night that would even the base load and you do not need all the additional installation. That is true, except green electricity generation  usually is not optimal for base loads.

My view is it cannot be done the way the enthusiasts want it done. We shall never get everybody to cooperate sufficiently to achieve the necessary reductions because society simply cannot afford it. We need a different approach, and in some  later posts, I shall try to offer some suggestions.

A Food Crisis?

Arguably the biggest current problem for the world is the food supply, and particularly grain. About a third of all wheat and barley exports and about one fifth of the corn comes from Ukraine-Russia, and as you may have noticed, there is currently a war that is becoming bogged down in Ukraine while Russia is being sanctioned. Ukraine plants about 6 million hectares in wheat, and that has to be planted by May. I assume there also has to be some earlier soil preparation so time is running out. On top of that, it appears the weather has been very unkind for grain growing in China as heavy rain delayed planting. China’s wheat crop is the largest in the world, three times greater than the US, and 80% greater than Russia’s, however China remains a net importer and Chinese production this year have been estimated to be reduced by about 20%. Some of the problems for Ukrainian production are obvious, but others less so. Besides the actual problem of planting and managing the crops in a war zone that unfortunately is focusing its attention on some of the major grain growing areas, there is the problem of obtaining sufficient fuel and fertilizer.

The sanctioning of Russian oil means that fuel costs are almost certain to rise, and the turning off of Russian gas turns off the feedstock for the making of the hydrogen and providing the energy for ammonia production, which means that fertilizer in Europe will become very much more expensive. Such problems can be solved. There are other ways to produce the fuel and the fertilizer, but such alternatives cannot be just turned on overnight. Building a new route in the chemical industry takes many years even to build your first conversion plant, and nobody will build one until they see how the first one operates. So for the time being we are stuck with what we have.

The rich countries will grizzle but meet the increased price, but what will the poorer nations do? My guess is they will continue buying from Russia, sanctions or no sanctions. Political niceties go out the window when then choice is to starve.

What can be done? Obviously, ending the war would be a starter, and hopefully that will come to pass, but the various sanctions will stay, so the Russian wheat crop will be unavailable to the West. More interesting is the problem of if the West imposes sanctions on any country buying Russian wheat. If China purchases it, that will relieve the pressure on the rest of the world to some extent because China will get its wheat from somewhere. Fortunately, China has had a policy of storing surplus so its reserves may make a major contribution to easing the problem.

The obvious solution is to increase production elsewhere. At first sight, that is obvious, and in some places probably achievable, such as Sudan and Nigeria, except again part of the reason these places do not grow as much is because they have internal fighting. Climate change is also a big factor. Many countries have marginal production, but it is unclear whether growing conditions will get better or worse. New Zealand provides an example of a further problem. New Zealand is a net wheat importer, even though it can grow its own. The reason it imports is that its farmers can make more money growing something else, and that means if it did switch to wheat production in some regions, it would have to switch off something else and raise the price.

We have to be careful we are not just moving the problem. To switch in some regions that do not grow much at all would require a big investment in harvesting machinery, purchase of seed and fertilizer, and find skilled farmers. Seed is more troublesome than it might seem because seed often carries pathogens that suddenly thrive in a new environment. Thus the purchase of special seed in Bangla Desh in 2016 introduced a fungus that halved overall production. In some cases it may be better off to make the switch in what you grow because there are other flours that can be used, such as from legumes (less nitrogen fertilizer required) or millet. Some farmers could try that, but what happens if they guess wrongly? The invisible hand of the market is not kind to those who guess wrongly, so farmers tend to stick with what they know works well for them. Who carries the risk if we need big change?

We obviously have to do something, but what?

Solar Energy in India

There is currently a big urge to move to solar energy, and apparently India has decided that solar energy would greatly assist its plans to deal with climate change. However, according to a paper by Ghosh et al.in Environmental Research Letters, there is a minor problem: air pollution. It appears that while India is ranked fifth in the world for solar energy capacity, parts of it, and these tend to be the parts where you need the power, suffer from growing levels of particulate air pollution. There are two problems. First, the particles in the air block sunlight, thus reducing the power that strikes the panels. Second, the particles land on the panels and block the light until someone cleans the detritus off the panels.

I am not sure I understand why, but the impact on horizontal panels ranged from 10% to 16%, but the impact was much greater on panels that track the position of the sun (which is desirable to get the most power) as they suffered a 52% loss of power from pollution. Apparently if it were not for such pollution it was calculated (not sure on what basis – existing panels or proposed panels) to be able to generate somewhere between an additional six to sixteen TWh of solar electricity per year. That is a lot of power.

But if you are reducing the output of your panels by fifty percent, that means also you are doubling the real cost of the electricity from those panels prior to entering the grid because you are getting half the power from the same fixed cost installation. The loss of capacity translates into hundreds of millions of dollars annually. China has the same problem, with some regions twice as badly off as the Indian regions, although care must be taken with that comment because they are not necessarily measured the same way. In all cases, averaging down over area is carried out, but then different people may select different types of area.

So, what can be done about this? The most obvious approach is to alter the sources of the pollution, but this could be a problem. In India, the sources tend to be the use of kerosine to provide lighting and the use of dirty fuel for cooking and heating in rural villages.

The answer is to electrify them, but now the problem is there are 600,000 such villages. Problems in a country like India or China tend to be very large, although the good news is the number of people available to work on them is also very large. Unfortunately, these villages are not very wealthy. If you want to replace home cooking with electricity, and domestic heating with electricity, someone has to pay for electric ranges. One estimate is 80 million of them. Big business for the maker of electric cookers, but who pays for them when the rural people are fairly close to the poverty line. They cook with fuel like biomass that gets smoky because that is cheap or free. Their cookers may even be home-made, but even if not so, they would have to be discarded as they could not be used for electric cooking.

There are claimed to be other benefits for reducing such pollution. Thus reducing air pollution would reduce cloudiness, which means even better solar energy production. It is also claimed that precipitation is inhibited from polluted clouds, so it is concluded that with more precipitation that would wash more pollution from the air. I am not sure I follow that reasoning, because they have already concluded that they will have fewer clouds.

If they removed these sources of air pollution, they calculated that an extra three TWh per year could be generated from flat surface panels, or eight TWh per year could be generated from tracking panels. The immediate goal is apparently to have 100 GW solar installed. It will be interesting to see if this can be achieved. One problem is that while the economics look good in terms of money saved from increased solar energy, the infrastructure costs associated with it were neglected. My guess is the current air pollution will be around for a while. It also shows the weaknesses of many solar energy projects, such as setting up huge farms in the Sahara. How do you stop fine sand coating panels? An army of panel polishers?

Exit the Dinosaurs

According to National geographic, an anniversary is coming. Not sure which anniversary, but it’s a biggie – the anniversary of the extinction of the dinosaurs. Well, at least the anniversary of the Chicxulub crater, which is about 180 km wide. This would be caused by an impactor of about 10 km diameter, which perhaps shows how fierce these impacts were. Of course, there are arguments over whether it was the asteroid that killed the dinosaurs, but it certainly would not have helped. It was about the same time that in India the Deccan traps formed, where huge amounts of basalt were extruded out from the mantle.

So, what happens when an asteroid strikes? We have some idea relating to smaller ones because hydrogen bomb tests have provided evidence of the consequences of the localised production of heat equivalent to the low hundreds of Mt of TNT. At the point of impact extremely intense pressure is generated, which is transmitted into each body by waves. As the smaller body enters the major body, all points of contact lead to the generation of pressure waves that radiate into both bodies. Waves from different point sources will lead to vibrations in different directions, the vibrations of the rock become too great and the rock simply pulverises, which leads to the absorption of energy. The next waves have to travel through pulverized material, wave interference results, and huge amounts of energy are absorbed. Modelling from the hydrogen bomb data leads to the following conclusions. At a velocity of 10 km/s, an impactor of diameter of 1 km will generate a crater 12.2 km diameter and 0.6 km deep; an impactor of diameter of 0.1 km would generate a crater of diameter of 2.6 km and depth of 0.55 km. As a final example, with an impact velocity of 5 km/s and an impact diameter of 2 km, the crater diameter would be 11.5 km and of depth 4 km. Once the distance is big enough that the impact acts as a point source, the shock wave continues through to the other side of the body, where it can be reflected, or disrupt the surface. It may be that the reason the Deccan traps occurred at about the same time may be because the asteroid caused the eruption. I think that on Mars the Tharsis volcanic field was caused by the Hellas impactor, and maybe Elysium by the Argyre impact. They are more or less on opposite sides of the planet.

Anyway, the asteroid vaporized just about everything above a layer of granite, and it dug an impressive hole in that too. There was not only the impact, but apparently the seafloor where it landed would have had considerable amounts of gypsum, and that would have vaporized and probably pyrolyzed. The net result was from the combination extreme acid rain, helped by the Deccan Traps, there was ocean acidification, and this led to a collapse of plant production, the base of the food chain. Anything large would die of starvation. The survivors tended to be the small, the rat-sized mammals and birds.

The time taken for extinctions is controversial because there are no continuous fossil beds for the period, and the probability that an animal will be fossilized is very small. Accordingly, there may have been small numbers of animals that lingered on. There was also a general decline before the impact, perhaps because of climate change, and many of the dinosaurs had got so big any minor change would prevent them getting enough food. Prior to the impact, the average temperatures rose rapidly by three to four degrees Centigrade, and that would greatly affect plant production. Plants cannot migrate other than through their seeds being transferred, so it is possible very large numbers of plants were too stressed to be productive. Alternatively, plants may have evolved to be less nutritious. When you are slow moving and need tonnes of food, any small adverse change can be deadly. Marine animals were particularly susceptible, and ichthyosaurs became extinct well before the impact.

We don’t know when the impact occurred to within a few tens of millions of years, so what was that about an anniversary? There is one site in North Dakota where there are fossilized bones of fish, and they perished just as they were speeding up a growth spurt, which would arise due to an increase in the food supply. Bone tissue made during a growth spurt is spongier. That suggests they died in the Northern spring. So we know when in the year, but not which year. Apparently sturgeon and paddlefish died with debris of tektites embedded in their gills. These tektites (which are glassy globs) were thrown up by the heat of the impact, but would start to come back down after about fifteen minutes and would soon stop. For these fish to have tektites embedded, they died almost immediately after the impact. Further, all the bodies face one way in one layer, and the other way in the next layer. There were huge tidal waves sloshing around all the way up to the Dakotas. (Note that this part of North America was a river valley.)

The Southern Hemisphere would have an advantage here, because going into autumn, life is getting ready for winter, it has fattened up, and it is ready to hunker down. That might give some advantages, nevertheless it did not seem to. The extermination of life here was just as severe. Yet oddly enough we have the tuatara in New Zealand, the only remaining species from the order Rhynchocephalia which originated in the Triassic, about 250 million years ago. It is a rather slow-moving animal, so maybe it low energy requirements got it through this disastrous period.

Saving the World – with a Stink!

The latest from Nature (vol 602, p 202) on how to save the world: collect urine. This is, of course, a well-established technology – the ancient Romans did it. They collected it from special urinals through the city and did all sorts of things with it. One of the more interesting, according to Catullus, was to use it as a tooth whitener! The urine was also collected and taken to a fullonica (a laundry) and after dilution, was poured over dirty clothes. A worker would stand in a tub and stomp on the clothes – conceptually similar to a modern washing machine. It was similarly used to clean wool and remove the fats, etc, to prepare it for dyeing. It can be used to make leather soft, and when mordant dyeing, it can also make the dyes brighter. And, of course, if you feel so inclined, you could advance to medieval times and make saltpetre, which is essential for gunpowder. But urine uses come and they go, so how now do they save the world?

The lead, apparently, comes from Sweden, and in particular the island of Gotland. They are going to put some public flush-free urinals around the island and hope to collect about 70,000 litres of it. They are then going to dry this into chunks apparently with the texture of concrete, which they powder and compress into pellets for fertilizer. Currently, a local farmer uses the product from a pilot plant to grow barley which goes to a local brewery and thus forms a complete cycle. That is real recycling.

The problem here, of course, is it is necessary to separate the urine from the rest of the sewage. Either you need separate toilets, or you have an interesting design issue. There are, apparently, a number of similar projects in a number of different countries. Currently, it has been estimated that humans produce enough urine to replace about ¼ of our nitrogen and phosphate fertilizers. It also contains potassium and many  micronutrients. Also, by not flushing, we save a lot of water. As for problems, the first we face is we have to redesign our toilets and then design a way for how we treat it. The treatment will have to be dispersed, thus a building might have its own urine system. Currently, we have one sewage system that takes everything, but we cannot afford a further such system, especially since for a dispersed system sooner or later some people will put anything down the second system. As for “saving the world”, one estimate is that communities that do this could lower their overall greenhouse emissions by up to 47%, their energy consumption by up to 41%, fresh water usage by 50%, and nutrient  pollution from waste-water by up to 64%. The greenhouse emission savings go a very long way to saving the planet alone, provided everyone did it, because if properly managed, not only do you reduce methane production, but also the much more difficult nitrous oxide, which is more long-lived than carbon dioxide. Then, if you deal with this properly you could get more imaginative: bags to collect urine from cows! Fix the dairying greenhouse problem in one go.

Sounds good, so what’s the problem? Toilet design, to start with. What people come up with tends to be unwieldly, awkward to use, and outright smelly, especially if urine gets mixed with the faeces. A clever redesign of a toilet might overcome that, but now you have to collect the separate urine, with no additional water added. It will drain, but leave a smell. Either you collect in a tank that then has to be taken somewhere, or you re-pipe the building. Then what? In an urban setting, it is not practical to install a separate sewer system, and since it is about 95% water, transporting is very expensive for what you get. One trick is to hydrolyse the urine (because much of the nitrogen is present as urea) then add something like magnesium sulphate (maybe supplemented with some phosphate) and you get a precipitate of magnesium ammonium phosphate (struvite), which is an excellent slow-release fertilizer. The problem now is the phosphate in the urine is not balanced with the nitrogen (which is why supplanting it is desirable), you have lost the potassium, and does the average household want to do this every weekend? As you can see, saving the world is more difficult than it looks like at first sight.