Thursday, 15 August 2019

Global Warming?

     I've noticed that nearly all the propaganda information on global warming is about just that: global warming, not carbon dioxide. No, I am not "denying" the science. In order to do that, I would have to become an efficient climatologist. In any case, I don't think anything is gained by the parties abusing each other as "deniers" or "warmists". But I am sceptical - because that is what a scientist is supposed to be. When you hear that "the science is settled", we who are not climatologists, but who nevertheless have a background in science, know that the statement is ridiculous. Which science? And to what degree is it settled?
     This particular science breaks down into four questions:
  1. Is global warming occurring, and to what extent?
  2. To what extent, if any, is it caused by human beings - particularly by the increase in anthropogenic CO2?
  3. How bad is it going to get?
  4. What can be done about it?
    It should be noted that the answers to each of the questions is dependent on the ones before. Also, every scientific statement carries a margin of error, and these errors are cumulative. In other words, if 1 is uncertain, 2 is doubly uncertain, and so on.
    This being said, the first question is the easiest to answer. Although we can quibble about some of the data, the average global temperature for the 21st century is higher than for the 20th.
     It is second where the science becomes murkier. The proponents of the theory hardly ever provide us with evidence. They bombard us with information about how the shrinking Arctic ice pack  and shrinking glaciers, of flowers blooming earlier, and so forth. We know that! But what they don't tell us is how it relates to carbon dioxide. They just assume that if global warming can be proved, it stands to reason that it must be wholly due to the extra carbon dioxide being pumped into the atmosphere. But is it? That carbon dioxide is a greenhouse gas, which serves to trap the sun's heat, and restricts its radiation into outer space, is not in dispute. It ought to contribute to warming. But how much?
      Firstly, climate is constantly changing. It is well established that the earth has gone through several cycles of warming and cooling. The Roman Warm Period covered the period between 250 BC and 400 AD. That was followed by a colder spell, which in turn was replaced by the Medieval Warm Period from about 950 to 1300. A brief web search will turn up any number of commentators arguing from entrenched positions that this warm period was not the same as the current warming or that, on the contrary, it was the same. After that came the Little Ice Age, the coldest period of which occurred between 1645 and 1715, but which did not peter out until about 1850. You will note that the end effectively coincided with the start of the industrial revolution. Therefore, unless they are going to claim that the industrial revolution was responsible for ending the Little Ice Age, why do so many people use the start of the industrial revolution as their base date for temperature increases?
     The logic is perfectly clear. Either:
     (a) the Little Ice Age, which had already run for more than 400 years, would have continued at least another two or three centuries without the advent of the industrial revolution; or
     (b) much of the current warming must be part of a natural trend.
     Because of this, two Australian scientists have recently argued that the current warming is completely natural. Perhaps. But just the same, as mentioned above, carbon dioxide is a greenhouse gas, and ought to be having some effect, but how do we distinguish its effects from natural causes? One obvious method would be to find a linear relationship between the amount of CO2 and temperature increase. However, this is exactly what we do not find. I am not referring to the normal year-by-year fluctuations. Evening out those fluctuations, it is clear that temperatures have been rising during the twentieth century, but have leveled out during the twenty-first, while the amount of CO2 has been constantly rising. No-one denies this. Various explanations have been proposed for this plateauing, but they all come down to the same thing: the system is more complicated than the experts predicted. One specialist suggested that the data could be explained if the sensitivity of climate to COwere only a third of what had been assumed. I regard this as an open question. Furthermore, if this century's warming plateau is hotter than last century's temperatures (which is what a plateau means), then the hottest year on record is bound to be one of those years. It is also virtually inevitable that it will occur during an El Niño year. Just the same, the last couple of years have been especially hot, which might suggest that we are in for a new period of warming. Only time will tell, but if it occurs, this will be strong evidence implicating CO2, though it will still not be the whole cause.
     This brings us to point no. 3: how bad is it going to get? With regard to this, we are constantly bombarded with estimates based on various models. Let me state, categorically, that all this is rubbish! None of these models predicted the leveling of temperature in the last twenty years. If a model's predictions are wrong, then the model is wrong. This is scientific principles #101. It is one of the first things you are taught when learning the scientific method. The only model which can hold any water is one which correctly predicts what has already happened. When such a model is presented, we can take seriously its forecasts for the future, but until then we can safely assert that the factors influencing climate are too numerous and complex to fit into any current model.
     One of the reasons so many are skeptical about anthropogenic global warming is that we have been fed so many alarmist predictions that we have become like the listeners to the boy who cried wolf. Does anyone seriously believe, for example, that we have only twelve more years to save the world? That we face, not only catastrophe, but human extinction? It's all been said before. Back in 1989 (yes, 1989!) a senior U.N. environmental official was predicting absolute disaster if global warming wasn't reversed by 2000!
     So allow me to state my own tentative conclusions:
  • Global warming is real, and will probably continue to some extent.
  • It is partly natural, and partly man-made.
  • It is manageable, and nowhere near as catastrophic as made out, but we need to reverse the trend.
    That bring us to point 4: what can be done about it? Ironically, it would be a relief if global warming were wholly man-made; we could then do something about it. But if global warming is completely natural, then it is impossible to predict how hot it will get, except that, based on history, it would probably mean an increase in a degree or two for several centuries, followed by a cool spell. But since carbon dioxide is a greenhouse gas, whether its effect is large or small, if we keep pumping it out, the temperature will keep going up and up. Eventually a point will be reached where drastic action will have to be taken. There is no reason to think it can't be managed, but the longer action is delayed, the more extensive the action will have to be when the crunch finally comes. It would be best to gradually put the brakes on now.
     Ultimately, however, real progress will not take place until renewable energy becomes as cheap as fossil fuels. The way science works, that will eventually happen. In the meantime, much of the proposed action makes just plain common sense, even without global warming. I have solar panels on my roof simply because, in the long run, they save money. Keeping your home insulated, so that it requires less electricity is also good economics. Aircraft contribute 2½% of human produced CO2, but that is half what it used to be a couple of decades ago, simply because of greater fuel efficiency. Electric cars will cut down on particle and carbon monoxide pollution, but as far as carbon dioxide is concerned, that depends on exactly where the electricity comes from. In many cases, it is produced by burning coal.
     Personally, I would like to see the gradual elimination of fossil fuels. In the first place, they will eventually run out, and they could be put to better use in the production of industrial hydrocarbons. In the second place, oil is financing our enemies, the Salafist Muslims. The sooner the Middle East in general, and Arabia in particular, revert to their original semi-civilised state, the better it will be for everybody else.
     But as far as Australia is concerned, the picture is clear: there is practically nothing we can do. The way some people talk, anyone would think our CO2  just floats over the continent changing our climate. In fact, it mixes with every other nation's. The 558 million tons of greenhouse gases we produce annually is just 1.22% of the world's total: roughly one 80th. China's contribution is 27%. We could convert wholly to renewable energy tomorrow, and it would make no difference the world climate. If we did nothing, it would also make no difference. I don't personally recommend either extreme. We should be a good world citizen, but there is a happy medium between doing nothing, and wrecking our economy for no useful purpose.
     As for the Adani coal mine, even if India could obtain no coal from any alternative source (but, of course, they could), it would add just 1/40th of the Australian output of greenhouse gases. That's 1/40th of 1/80th. Anyone who thinks stopping Adani will save the Barrier Reef has rocks in his head. William F. Buckley used to tell opponents: "I won't insult your intelligence by assuming that you believe what you just said." Reluctantly, however, I have come to the conclusion that some people really are that stupid.
    Of course, there is one source of power which produces no greenhouse gases: uranium. Australia possesses 30% of the world's uranium, and is the third biggest exporter. Many of our customers use it to produce up to half their electricity. They have never had an accident, and the new style of reactors are especially safe. Disposal of waste may be a problem, but the best solution is to simply bury it, preferably vitrified, in a geologically stable area with no ground water. Half of Australia fits those criteria. We could even make money burying other countries' wastes. But the people who are loudest in the global warming debate have some sort of phobic reaction to the idea of uranium.

     Up-date January 2020. There's an old adage: Never let a good crisis go to waste! This appears to be the motto of certain people pontificating that the catastrophic bushfires being suffered by Australia are "caused" by global warming. A more accurate statement is that they are contributed to by global warming. The fires are the result of heat and a prolonged drought, both of which are regular events in Australia. As I said before, global warming must be factored into every weather event, and it is reasonable to suspect that the drought and heat wave would be smaller without global warming, but anyone who thinks getting world temperatures back to those of (say) the 1950s is going to get rid of the problem has rocks in the head.
     Other factors impact on bushfires. An obvious one is population density. Since 80% of bushfires are caused by people, either deliberately or accidentally, it is plain common sense that the more people there are in bushland areas, the more likely are bushfires. The second is the fuel load of the forest. White settlers have given up the Aboriginal custom of low intensity fires which consumed the dry undergrowth, but prevented high intensity fires. As the Bushfire Front has pointed out, the only way to prevent megafires is to conduct low intensity prescribed burning. These two factors dwarf any contribution from global warming.
     Added to this, of course, is the fact that we contribute only 1/80th of anthropogenic carbon dioxide. While we should act as good world citizens, we have to accept that reduction of Australian greenhouse gases will have close to zero effect on the frequency and size of bushfires. We should divert our energies into programs which can actually work: like increasing prescribed burning to prevent bushfires, and bolstering our fire-fighting responses, so that fires can be extinguished before they become catastrophic.