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Post by unkleE on Sept 19, 2016 4:06:20 GMT
How much it will rise, how dangerous that is and what we should do about it are not facts, but forecasts and opinions. I'm sorry, James, but I think this is a quite misleading statement. The Oxford dictionary's first definition of fact is: "A thing that is known or proved to be true." I presume you are using the word with something like that meaning, so let's examine the implications of that. 1. It is sometimes said that evolution is both a fact and a theory. It is considered to be a fact that life has changed over time, while the details of how it has changed is a theory. The theory has the following features: - a load of evidence - fossils, DNA, rates of change of processes, dating methods, etc
- known sciences - palaeontology, biology, geology, physics, etc
- an understanding of mechanisms, primarily natural selection
- the consensus of the vast majority of scientists in these fields
- significant doubts about some aspects of the process (e.g. the mechanism of abiogenesis, group selection, etc)
So while evolution may not be a proven fact in the terms of the Oxford definition, it can be said to be known with a high degree of probability, while there are uncertainties about some details. 2. We can say something similar about the Big Bang, which is also a theory, and also has these features: - a load of evidence - the red shift, cosmic background radiation, astronomical observations, etc
- known sciences - principally cosmology and astrophysics, but also physics and chemistry
- an understanding of mechanisms, often by developing mathematical/computer models which make successful predictions
- the consensus of the majority of scientists in the field
- significant doubts about some aspects of the process (e.g. inflation, the multiverse, etc)
Again, few these days question the big bang, even though there are many uncertainties and it cannot be directly observed. But it fits the facts better than any other hypothesis. 3. Now really, the same is true in the case of climate change: - there is a load of evidence - temperature, atmospheric carbon, ice cores, statistics, etc
- known sciences - climatology, meteorology, physics, etc - the same sciences that are used in weather forecasting
- an understanding of mechanisms, primarily via known physics expressed in complex computer models
- the consensus of the vast majority of scientists in these fields
- significant doubts about some aspects of the process (e.g. local effects in space and time in a complex, chaotic system)
So on similar grounds we can reasonably say that while climate change predictions are not "facts", they are based on well established data, theory and knowledge. They are the best fit to the data, and because we are dealing with much shorter term phenomena than evolution or the big bang, the theory can be more easily updated and refined. So unless we are willing to doubt the big bang or evolution, we should also accept, at least prima facie, the reality and the science of climate change. So it is interesting to speculate on why you and others don't accept something that is so well-based in science. We can examine several possible hypotheses: 1. The scientists have made an enormous honest mistake and have simply gotten the science wrong. I can't believe so many scientists have made the same mistakes. 2. There is some sort of global Green/anti-capitalist/insert other possibilities here conspiracy that has somehow taken over scientists from almost every country in the world. Perhaps we should blame the Illuminati. Maybe I'm naive, but I can't see how that could be possible. 3. Climate change is a fact, the predictions are generally correct, but the few climate change sceptics have got hold of some small discrepancies and mistaken them for serious flaws. These seems possible, though very short-sighted. 4. Climate change is a fact, the predictions are generally correct, but there is a global conspiracy by the oil industry, the Murdoch press and a few conservative allies to suppress and fight the science, in a somewhat similar manner to how the tobacco industry fought against the connection of smoking and lung cancer. There is some evidence of this, and I find it believable as a part explanation, though not a full one. 5. Something else - but what? It is hard to see how all the scientists can be wrong unless there is a conspiracy, but if there is a conspiracy, I find it much more plausible that it is to delay climate change action than to hasten it. So I return to your comment. There are indeed some facts about climate change: 1. You agree that "human induced CO2 is causing the temperature of the earth to rise". (BTW, this is one of the facts that used to be denied by conservatives in Australia, illustrating the point I made before.) 2. Climate science is based on known and tested physics applied to a complex chaotic system (and so can be expected to be right about the large scale predictions but less right about smaller scale predictions). 3. There is a mountain of data to use in the models that scientists have developed, and these models almost universally predict dire consequences. 4. There is still doubt about the fine details, as can be seen in the error bands on predictions. But even the lower range of the error bands will be dire. 5. Almost all relevant scientists agree with the broad predictions, that the consequences will be dire, and we should be acting now. 6. Effective action is being impeded by a small bunch of conservatives who (in my experience here in Australia) often distort or misrepresent the facts. Those are facts. I haven't said anywhere in those facts that therefore the predictions of climate change are definite "facts". But they are as close to facts as we need to get moving on action, just as evolution by natural selection, and the growth of the universe from the big bang are as close to facts as we need to accept them. The conservative movement against climate change action is already doing enormous harm to the future of billions of people. For example, aid workers in the pacific Islands, Bangladesh, Nepal and North Africa are already seeing people suffering because of climate change, and it can only get worse for them. And it is worth noting that the costs of action are far less than they used to be, as renewable energy is not competitive in many cases, and would become more competitive if governments, business and communities resolved to make the move now that we are going to have to make sooner or later. Thanks.
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Post by James Hannam on Sept 21, 2016 13:52:37 GMT
Well, I know we don't agree on this, but here goes.
You may be aware that on 23 June, the UK voted to leave the EU. During the campaign, economists from HM Treasury, the OECD, the IMF, the big banks and the think tanks all assured us that this would lead to an immediate recession, the Chancellor said there would have to be an emergency budget to raise taxes and cut spending, inflation would rise and house prices fall.
Since 23 June, you have not been able to move for all the above experts changing their minds. None of the predicted effects have happened. The simple fact is, of course, we cannot make accurate economic predictions. The experts were guessing before the vote when they were busy telling Leave voters that we should be listening to them as we were economic illiterates and, they are also guessing now, just in the other direction.
We hope agree that macroeconomic forecasts are not worth the paper they are written on and that we should be sceptical about them. In fact, we should simply ignore them as far as possible and certainly not make important decisions like whether or not we want our country to be independent cased on them.
Why can't rely on them? The underlying theories of rational choice theory, the efficient market hypothesis and basic rules of supply and demand are all reasonably sound. Unlike macro-economics, micro-economics can and does predict and explain what we see. But the economic system is too complicated to predict even if we understand the underlying forces. It is chaotic. That doesn't mean (as you say) we can predict large scale predictions rather than small ones. It means that very small changes to initial conditions lead to massive changes done the road. This means that predictions of any sort are impossible once we get beyond the immediate horizon. The only rational way to make a prediction is extrapolation over the equivalent timeline you've got.
Like economics, the climate cannot be predicted. It just can't. It doesn't matter if we understand the underlying physics. There is no read across from the micro to the macro scale. I know you have faith in the computer models. You shouldn't until we have a proven track record of successful predictions that beat a straightforward extrapolation. Until then, the only rational thing to do is use the best long term extrapolation that we have, which is a .85 degree rise in 130 years or so. This is not something that need alarm us but, all other things being equal, is worth keeping an eye on and moving to non-carbon energy as it becomes cheaper.
The tone of climate scientists is exactly the same as the tone used by the pro-EU economists. We were told that we don't know what we are talking about and voices challenging the experts shouldn't be broadcast. The experts were wrong. In this case, we found that out in short order. With the climate, we'll have to wait a few decades.
On power generation, I'm quite happy to use non-carbon sources where that makes sense. In Australia I'm sure solar makes a lot of sense. It makes none at all in the UK. We may end up using a mix of offshore wind and nuclear back up. What is unacceptable is to waste money on expensive ways to generate power when much of the world has no money to waste.
Best wishes
James
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Post by ignorantianescia on Sept 22, 2016 17:46:22 GMT
James, I'm only going to comment on the economical aspects, but I could similarly preface this post about how unlikely agreement is. I'll try to keep it brief. You may be aware that on 23 June, the UK voted to leave the EU. During the campaign, economists from HM Treasury, the OECD, the IMF, the big banks and the think tanks all assured us that this would lead to an immediate recession, the Chancellor said there would have to be an emergency budget to raise taxes and cut spending, inflation would rise and house prices fall. Since 23 June, you have not been able to move for all the above experts changing their minds. None of the predicted effects have happened. The simple fact is, of course, we cannot make accurate economic predictions. The experts were guessing before the vote when they were busy telling Leave voters that we should be listening to them as we were economic illiterates and, they are also guessing now, just in the other direction. Think tanks can definitely be dodgy, but I would be interested in references for the Treasury, OECD and the IMF predicting an immediate recession. To the best of my knowledge the macroeconomic consensus is around a 4% reduction in GDP by 2030 compared to a ceteris paribus scenario. The UK may not notice all that much during 2016 either. I'm similarly curious for evidence of experts having changed their minds. I only kept up with this very little, but my impression is that the macroeconomists feel vindicated by events so far, but that they were surprised by the drop in the Pound. We hope agree that macroeconomic forecasts are not worth the paper they are written on and that we should be sceptical about them. In fact, we should simply ignore them as far as possible and certainly not make important decisions like whether or not we want our country to be independent cased on them. Many of the authoritative studies weren't unconditional forecasts, but conditional modellings, which are relatively reliable and well understood. Why can't rely on them? The underlying theories of rational choice theory, the efficient market hypothesis and basic rules of supply and demand are all reasonably sound. Unlike macro-economics, micro-economics can and does predict and explain what we see. But the economic system is too complicated to predict even if we understand the underlying forces. It is chaotic. That doesn't mean (as you say) we can predict large scale predictions rather than small ones. It means that very small changes to initial conditions lead to massive changes done the road. This means that predictions of any sort are impossible once we get beyond the immediate horizon. The only rational way to make a prediction is extrapolation over the equivalent timeline you've got. Macroeconomics are quite well understood, in broad outlines at least. The problem is that policymakers and the media do not transfer macroeconomic knowledge well. This is because the expertise that is relevant during a crisis, that of the business model, is politically unpalatable for the right and the centre.
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Post by James Hannam on Sept 23, 2016 8:46:17 GMT
Think tanks can definitely be dodgy, but I would be interested in references for the Treasury, OECD and the IMF predicting an immediate recession. To the best of my knowledge the macroeconomic consensus is around a 4% reduction in GDP by 2030 compared to a ceteris paribus scenario. The UK may not notice all that much during 2016 either. Here's HM Treasury's short term forecast on a vote to leave: www.gov.uk/government/uploads/system/uploads/attachment_data/file/524967/hm_treasury_analysis_the_immediate_economic_impact_of_leaving_the_eu_web.pdfTo quote the executive summary: "The analysis in this document comes to a clear central conclusion: a vote to leave would represent an immediate and profound shock to our economy. That shock would push our economy into a recession and lead to an increase in unemployment of around 500,000, GDP would be 3.6% smaller, average real wages would be lower, inflation higher, sterling weaker, house prices would be hit and public borrowing would rise compared with a vote to remain." Note the word 'immediate'. The Guardian (of all publications) called out the OECD for getting it wrong yesterday: www.theguardian.com/business/2016/sep/21/oecd-does-a-u-turn-over-brexit-warning-as-it-revises-growth-forecast-for-BritainA summary of the mass reverse-ferret from macro-economic forecasters: blogs.spectator.co.uk/2016/09/brexit-bounce-continues/And, just for fun, some commentary on how macro-economics can't accurately predict a hangover the morning after a bottle of whisky: www.telegraph.co.uk/business/2016/09/22/look-at-the-evidence-not-the-economists-for-the-effects-of-the-b/ . Note that the author of this article is gloating a bit for getting it right on Brexit, but that was luck too. He had no more way of knowing than all the others who got it wrong. The condition was a vote to leave. It happened and the forecasts were wrong. Admittedly, the hardcore Europhiles have retreated from apocalypse now to apocalypse postponed. And again, that may or may not happen. The point is, no one has a clue because we lack any tools able to make accurate macro-economic predictions. Of course, that entire paragraph is highly contested and political. Which just proves my point. A faculty of economics professors in 2016 is no more worth listening to than a faculty of doctors in 1800. I expanded on that analogy here: www.huffingtonpost.co.uk/dr-james-hannam/economics_b_6953320.html?Best wishes James
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Post by unkleE on Sept 24, 2016 12:09:54 GMT
Hi James, Many cases of disagreement about opinions arise because of disagreement about the facts, which in turn arise because of differences in how the opponents determine what they think are the facts. I think that is the case here. So I am hoping that a discussion of how we arrive at our versions of the facts may be constructive. I note straight away that you offer no references, no evidence, for your assertions about climate change, only an analogy. I’m not saying there are no such evidences, only that you haven’t presented them. So I want to ask you if you’d mind addressing, please, three points. 1. An inappropriate analogyYour main point (taking more than half your response) is that just as (you assert) the economists got the results of the Brexit vote wrong, so have the climate scientists. Now I know little about the Brexit and I have no opinion on it. I know you do have a strong opinion, but I fail to see how it has any relevance at all. We all know that predictions can sometimes be right, sometimes wrong and sometimes partly right. I could give examples of all three, as no doubt you could. But so what? I could equally argue (though I wouldn't) that because scientists could predict where the moon would be in the future so well they could land people on it, so they can predict climate change accurately. Why should an analogy with a less reliable prediction be better than an analogy with a more accurate prediction? Economics can be regarded as a social science, though some don’t regard it as a science at all. But it has few established laws beyond the laws of arithmetic. Climate change, on the other hand, is a physical science, for which there are many known laws. There is really no comparison. If you wanted to make an analogy, one with the physical or biological sciences would be more appropriate. (Q1) So can we agree that rights and wrongs of the economics of Brexit have no bearing on the truths or otherwise of climate change? If you think otherwise, can you please justify that analogy? 2. Choosing between contrasting views of the factsAfter your assertions that we cannot predict climate, I did a little Googling, to see what came up. I don’t pretend this is representative, but it is illustrative. It soon became clear that there are widely divergent truth claims on matters which both can’t be right. For example: So what we believe will clearly depend on who we read and who we believe. My brief survey (of about 20-30 sites) suggested to me that: - The majority of sceptical reports (not all) were not written by climate scientists, and some were clearly fringe, comical or "ratbag" sites, or else extremely conservative politically, and tend to overstate their extreme conclusions.
- The majority of sites supporting climate change action were by climate scientists, or reporting climate scientists and journal articles. This supports studies which show that the vast majority of relevant scientists publishing on climate change take a view opposite to the scepticism that you espouse.
- Sometimes the sceptical sites cherry-pick the science to make their claims that climate change has been undermined or disproved, but when you read the original report, you find that is quite spurious. Some small aspects had to be changed, but the broad trends and the broad scientific agreement remained. For example, this blog says: "An article published today in Nature laments the dismal failure of climate models to predict climate a mere 5 years into the future, much less a century from now". This website repeats the claim. However the article in question reports on short term detailed predictions had not been accurate because they couldn't predict some short term changes, but longer term models predict averages and these predictions are still regarded as accurate. So the blog's claim was quite inaccurate. Contrary to the blog, longer term trends are easier to estimate than near future details.
So my questions to you here are these: (Q2) How do you choose, among the plethora of reports, who you believe? (Q3) Why do you choose a view that is contrary to the vast majority of climate scientists? When it comes to choosing a view on evolution, or the big bang, or Jesus mythicism, or the conflict thesis, you choose to accept the views of the consensus of experts, whose work is published in peer-reviewed journals and by reputable academic publishing houses, and you reject the views of the “ratbag” fringe. Why is it that on this issue you appear to do the opposite? (Q4) Why do you think that the vast majority of climate scientists have got it wrong (in your view)? I offered you a few alternatives in a previous comment. Do you think they are all honestly mistaken, or is there a conspiracy of some sort? If you could clarify your views here, we might be able to then consider what the evidence points to. 3. Risk assessmentI have had several relatives and friends diagnosed with cancer, and several die from it. In each case the doctors gave them diagnoses and prognoses, expressed in terms of percentages - 30% chances of survival in one case down to 3% in another. None of them disbelieved their doctor and said they’d prefer to wait until there was greater certainty. All accepted the diagnosis and the treatment offered. I’m sure you would do the same, even though there isn’t certainty in the diagnosis and prognosis. We define risk in simple terms = consequence x likelihood. In the case of cancer, the consequence is so severe (death) that the likelihood doesn’t have to be too high for us to accept treatment, and generally it is way higher than we need to make the decision. It is much the same with climate science. The consequences if the climate scientists are generally right are extremely severe, and while there is some risk that they may be wrong, and a larger risk that some details may not yet be right, the severity of the consequence is enough to overwhelm the uncertainties. So my question here is: (Q5) Why do you baulk at the level of accuracy offered by climate models and the almost unanimous agreement that the future is somewhere in the error bands, but you wouldn’t do the same (I presume) if you were diagnosed with cancer with the same probability estimate? These 5 questions aren’t traps, but I hope reasonable attempts to clarify to me your thinking and your source of information. I think answering them would allow the discussion to progress constructively. I hope you think so too. Thanks.
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Post by James Hannam on Sept 26, 2016 15:47:15 GMT
Hi UnkleE, “Many cases of disagreement about opinions arise because of disagreement about the facts, which in turn arise because of differences in how the opponents determine what they think are the facts. I think that is the case here.” I’m not sure we disagree on as much as you think we do. To be clear, we agree that human action is changing the climate and that CO2 emissions are increasing global temperatures. I think our main disagreement is you regard climate change as a great issue of our times and I think it’s all a bit meh. Question (1) “Your main point (taking more than half your response) is that just as (you assert) the economists got the results of the Brexit vote wrong, so have the climate scientists.” I fear I was not clear enough because I certainly was not saying climate scientists are wrong. I am saying that they cannot make accurate predictions about the future. Their models might be right or might be wrong. Either way, this will be down to luck rather than the virtues of the models. Now, we know the economists were wrong because they were good enough to make clear predictions about the effects of an event that has since happened. In a few decades time, we’ll be able to see which climate models were accurate and which weren’t. However, this won’t be because some were correct and some weren’t, it’ll just be some got lucky and some didn’t. “Now I know little about the Brexit and I have no opinion on it. I know you do have a strong opinion, but I fail to see how it has any relevance at all.” The Brexit analogy simply shows that where you have a complex and chaotic system, the mere fact you have lots of experts telling you something is going to happen is not evidence that it is going to happen. So my analogy is simply yet another refutation of the argument from authority. “I could equally argue (though I wouldn't) that because scientists could predict where the moon would be in the future so well they could land people on it, so they can predict climate change accurately. Why should an analogy with a less reliable prediction be better than an analogy with a more accurate prediction?” The distinction is between systems which are inherently unpredictable (like the economy, climate, politics, the weather, earthquakes, sporting events etc) and those that are predictable (like planetary motions or the trajectory of a bullet). We agree that climate is a chaotic system making it more analogous to the economy than to the moon’s orbit. “It has few established laws beyond the laws of arithmetic.” Not true. Economics has plenty of laws such as the efficient market hypothesis, supply and demand, Ricardo’s theory of comparative advantage, price stickiness etc. Microeconomics is successful at make predictions, much like some of the physical sciences. But there is no read across between the micro and the macro. Likewise, with the climate, statistical mechanics can produce astounding accuracy in the lab as can other experiments but it can’t be scaled up to predict the climate. Some references: - On microeconomics, Tim Harford’s The Undercover Economist is a brilliant intro. - On prediction and forecasting, Nate Silver’s The Signal and the Noise; Philip Tetlock’s Superforecasting. “(Q2) How do you choose, among the plethora of reports, who you believe?” On climate, I simply look at the past and assume that the future will be the same. The graph linked below shows that global average temperatures have increased by .6 degrees in the last 50 years and 1 degree in the last 100 years. So my prediction is a rise of 0.1 – 0.12 degrees a decade. As I do not think climate can be predicted with more accuracy than that, extrapolation is the only game in town. So I think 2100 will be 1 degree warmer than today and I’m pretty relaxed about that. The hiatus/pause/slow down/whatever, was just a reversion to the long term trend after higher than usual warming in the 1990s. I could be wrong, but that isn’t something that can be predicted at this stage. crudata.uea.ac.uk/cru/data/temperature/HadCRUT4.pdf“(Q3) Why do you choose a view that is contrary to the vast majority of climate scientists?” For the same reason that I ignore economic forecasts. I don’t think climate scientists are capable of making predictions that are better than ‘more of the same’. “When it comes to choosing a view on evolution, or the big bang, or Jesus mythicism, or the conflict thesis, you choose to accept the views of the consensus of experts, whose work is published in peer-reviewed journals and by reputable academic publishing houses, and you reject the views of the “ratbag” fringe. Why is it that on this issue you appear to do the opposite?” I do not chose to follow the view of the consensus of experts. I have reached my own conclusions based on solid evidence. And when in doubt, I just assume Tim O’ Neill is right about everything. “(Q4) Why do you think that the vast majority of climate scientists have got it wrong (in your view)?” The mistake of climate scientists is simply to believe their models have predictive power. That’s the same mistake made by economists, political pundits and many other people who claim to be experts. No conspiracy is necessary. “I have had several relatives and friends diagnosed with cancer, and several die from it. In each case the doctors gave them diagnoses and prognoses, expressed in terms of percentages - 30% chances of survival in one case down to 3% in another. None of them disbelieved their doctor and said they’d prefer to wait until there was greater certainty. All accepted the diagnosis and the treatment offered. I’m sure you would do the same, even though there isn’t certainty in the diagnosis and prognosis.” I would. But the reason I’d do that is that the ten year survival rates for cancer have increased from 25% to 50% in the last 40 years (http://www.cancerresearchuk.org/health-professional/cancer-statistics/survival). That is hard data which tells me that the cancer experts have made progress. Climate scientists have not got that track record and their success is no better than my simple extrapolation model. “So my question here is: (Q5) Why do you baulk at the level of accuracy offered by climate models and the almost unanimous agreement that the future is somewhere in the error bands, but you wouldn’t do the same (I presume) if you were diagnosed with cancer with the same probability estimate?” I think I explained this above. The other issue is what the effects of climate change will be. We have seen a rise of 1 degree so far and I’m expecting a rise of another degree with century. The story so far: - the UN notes that world food production is at an all-time high (http://www.fao.org/worldfoodsituation/csdb/en/) and there is no sign of a slowdown. Given temperatures in 2015/16 are at an all time high, it is strange that food production, that depends more on climate than anything else, is showing no ill effect at all. - Sea levels are rising by 3.4mm a year so will be 28mm higher in 2100 (http://climate.nasa.gov/vital-signs/sea-level/). Tidel range in the UK is regularly 15 metres. A 30cm sea level rise trivial and is easily managed. - We are seeing a small and gradual increase in global precipitation (https://www.epa.gov/climate-indicators/climate-change-indicators-us-and-global-precipitation). This is a good thing, not least because for most of the world drought is far worse than flood and far harder to manage. - Even increased CO2 levels are contributing to global greening (http://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fertilization-greening-earth) As I’ve said, I’m pretty relaxed about all this. I would strongly recommend Nate Silver’s book. It explains clearly the circumstances in which we can make good forecasts of chaotic systems (such as how we can now usually forecast weather four days out) and when we can’t. Best wishes James PS: No climate contrarian websites were consulted during the making of this post.
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Post by unkleE on Sept 28, 2016 12:05:41 GMT
Hi James, I'm so glad about this certification! Thank you for answering my questions fairly and courteously. I hope I can respond in like manner. Thanks for this, but it actually illustrates the point I first made in this latest bout on climate change, where I said "My observation is that acceptance of the reality of climate change by conservatives has been a slow iterative process. Beginning with total denial, each step has been very tenaciously fought before finally being grudgingly accepted"To this you replied: "the 'retreat' by climate sceptics is just an illusion caused by the media who get excited whenever they bother read what sceptics actually think, rather than just assuming they are all blanket denialists."But if we go back to 2008 on this forum, you said (my emphasis): "I am, I’m afraid, becoming a full blown sceptic about global warming. I used to be less sceptical, but every year the hard data shows temperatures not rising, the consensus becomes ever harder to sustain. ..... 1) We have seen no warming over the last decade. Models that extrapolate past trends are usually unreliable. 2) There is no agreement, as far as I can tell, on any of the direct consequences of warming. Increased rainfall, rising sea levels and worse weather have all been questioned. Several catastrophes such as the melting of the Antarctic Ice and the loss of the Gulf Stream are now off the menu."So it seems to me that your attitude has indeed changed or developed since then - not a bad thing of course, hopefully we all change and develop our opinions as new data comes in. But it does seem to illustrate my original point, that you now at least recognise as real, things that scientists, and I, argued were real back 8 years ago. At least some of your scepticism was wrong then, the so called "hiatus" now can be seen to be no more than just another variation in the general trend, with explicable causes (El Nino/La Nina), and each of the last couple of years and last couple of dozen months are breaking temperature records. But James that is not a refutation at all, simply an illustration (and arguable at that I imagine). No-one contests that predictions of complex systems can be wrong, but they can also be right. If you are going to use an analogy, why not use the analogy of your attitude to climate change 8 years ago ( "a full blown sceptic about global warming") and your conclusion now ( "human action is changing the climate and that CO2 emissions are increasing global temperatures"). That analogy shows the truth of my assertion that so many conservatives are awfully slow to accept as facts what most other people know are facts. But I won't spend any more time on Brexit, or analogies, because they are quite useless in establishing anything with any force. It is data and hypotheses that count, not dodgy analogies. Thanks for your detailed answer to my questions. I have picked this quote to respond to because I think it sums up what you have said. You don't trust the models because it is a chaotic system, therefore you don't trust the scientists, and thus you prefer straight line extrapolation as "the only game in town". James, this is madness, and quite indefensible. Let's look at a few aspects. 1. You are trusting your judgment (as a historian and human being) that extrapolation is better than modelling, against the opinion of almost every climate scientist. You have given no reason for that judgment except that you don't trust model predictions. You dismiss relying on the experts as "an argument from authority", and instead rely on a dodgy Brexit analogy and your own distrust of models. I can't see how that is any more justified than going against the experts on all the other matters I mentioned ( "evolution, or the big bang, or Jesus mythicism, or the conflict thesis"). An argument from authority isn't a logical fallacy if the experts know more facts that you or I do, it is just common sense, and we all do it every day. So I cannot see you have offered any sensible justification for your scepticism - at most, you could argue for careful acceptance of the experts' views. 2. You say "extrapolation is the only game in town" and then use a linear extrapolation. But there is nothing sacrosanct about a linear extrapolation - we could use a log-log extrapolation or a semi-log extrapolation, as well as many others, and they would likely give very different results. So why assume linear? Well you may not have thought about why, but I think it is summed up in your statement: "I simply look at the past and assume that the future will be the same." But this is an empty assumption without looking at the data, and without understanding the system we are dealing with. The future won't be the same as the past for several reasons. Global population is increasing, and so is the use of fossil fuels. And some climate effects are known not to be linear. Those who understand the system (which may be complex because of its size and variability, but the physics is well known) say there are reasons why temperature warming will speed up. For example, a lot of heat has been stored in the ocean, but this will eventually turn around and bite us, just as a brick house is a good insulator against summer heat, until the bricks warm up, and then it is a heat source that can make the house much hotter overnight and into the next day and beyond. So your assumption of linearity with the past is almost certainly wrong. The scientists know this, but you are ignoring it. If we didn't have models, but only extrapolation, we would have to use a form of extrapolation that fitted the physics, and it is by no means clear that linear is that. It depends on the form of the equations we think best represent the physics. A third problem with your extrapolation: you have used the periods of the last 50 years and the last 100 years to base your projections on. But who said they were the correct basis for projection? Just as extrapolation is only good if the type of extrapolation fits the type of data, so it is only as good as the starting period chosen. So what should it be? A cursory look at the annual temperature graphs suggest that things began to change about 1975 - that's around the year many experts think is appropriate, from the shape of the graph and from their understanding of the causes. And if we use the 40 years from 1976-2015, we see a rate 50% higher than the one you have referenced. And the way 2016 is going, and given that 2014 & 2015 were record high years., if we were having this discussion in another year or two, the figures would almost certainly look significantly worse for you. This shows again the folly of using simple extrapolation that takes no account of the physics - you can get a wide range of results with just minor changes in the starting period. So you may be comfortable with a rise of 0.1 – 0.12 degrees a decade, but it will most certainly be higher than that, even if we just use extrapolation. So extrapolation is nonsense, unless it is done with much better precision and science than you have used, and relying on it is madness. However poor the models may be, they will be better than extrapolation because they use all the data, they are based on the physics, and they can give error bands and probabilities. 3. We can argue about the models - as I showed before, some sources show they are predicting very well, others that they are not. But the "problem" is that they mostly predict long term trends, not detailed numbers for each year. Many of the criticisms are based on them not predicting the so-called pause, but now that the pause has ended and 2015/2016 are way above what we were experiencing before, the trend predicted by the models looks pretty right. So we cannot be sure they are precise, but we can be reasonably confident that they are better than extrapolation and pointing in the right direction. I have seen nothing from you or from the sceptical sites to refute that general conclusion. It is interesting that you reference Nate Silver. I know little about him, but he is an economist not a climate scientist, and so probably uses analogies and understandings like the Brexit analogy without showing how physics is as unpredictable as economics. Anyway, this scientist says he gets a whole lot wrong - another example of you preferring non experts. I'm sorry, but it is just like 6 day creationists to believe non-experts and disbelieve true experts. 4. Finally there is the matter of risk, which I have addressed, but which you really haven't responded to. Why would anyone take such an enormous risk as you are advocating, on such a flimsy basis, when the models are at least better than extrapolation? There is little doubt the temperatures will continue to rise, so we'll get somewhere undesirable sometime, whether sooner or later. There is also little doubt the fossil fuels will run out or become less economic than renewables one day. So some day we'll have to change our energy mix, and you are advocating risking enormous hardship on millions of people just to delay that day. It simply isn't worth the risk. So I can only conclude that you haven't justified your innate scepticism about climate models, your suggested course of action is based on a totally inadequate and misleading method (linear extrapolation without any understanding of underlying causes), and the result will be the high risk of an enormous global disaster. It just doesn't add up. You once referenced Jonathan Haidt on finding facts to fit our intuitive conclusions. That seems to me to be clearly true of you here, I'm sad to say. Of course, if Haidt is right, it is just as true of me. Which would mean that we are doomed as a species to always be at the whim of our prejudices. But my prejudice is supported by science rather than dodgy analogies and non-experts. But if the past 8 years is any guide, perhaps your views and public and political opinion will change on these matters in another decade. I fear that will be too late for many people in the worst affected areas, but hopefully not too late for most of us (though I'll be long gone before the worst hits). That I guess is small comfort. Thanks.
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Post by unkleE on Sept 29, 2016 4:11:13 GMT
Hi James, Further to my last, I decided I would look a bit more at extrapolation as a method of prediction. Firstly, to refresh your memory, here’s a brief summary of extrapolation. Data like we are dealing with are the result of many different processes, some systematic (like burning fossil fuels), some annual/seasonal, some diurnal, some over less regular periods (like El Nino), some apparently random, etc. This means that the data scatter. To extrapolate, we choose a form of equation (straight line, polynomial, logarithmic, exponential, etc) and calculate the least squares equation of best fit. The accuracy of the fit is measured by the correlation coefficient r and the coefficient of determination, r^2 - an r^2 above about 0.5 would be quite a reasonable fit. There are several problems with using extrapolation. (1) If the extrapolation is longer than the dataset, then it can be wildly inaccurate. (2) The choice of type of extrapolation can be arbitrary, and can greatly affect the result. For example, if you were doing an extrapolation of population growth (say of a bacteria colony), a straight line would give a quite misleading result, and an exponential extrapolation would probably be more appropriate (we know this because we understand the biology). If we ignore the known physics, as in your approach, the only way to choose which form of extrapolation is best is to choose the one with the greatest r^2. So I used the NOAA global temperature dataset, and ran some extrapolations from the 100 year (1916-2015) and the 50 year (1966-2015) data, as you suggested. And I tried 4 different extrapolations: (1) straight line, (2) polynomial order 2, (3) polynomial order 3 and (4) exponential. For the 100 year period, I got the following results: - The best r^2 was the 3rd order polynomial (r^2 = 0.87). Straight line was 0.79, 2nd order polynomial was 0.85 and exponential 0.58.
- The straight line predicted a global temperature at year 2100 of 1.3 degrees C above the 20th century average, but the other results were: Poly2 = 2.9 degrees higher, Poly3 = 8 degrees higher and exponential = 11.3 degrees higher.
For the 50 year period, all 4 results had almost identical r^2 = 0.89, but the predictions at year 2100 were: Straight line = 2.1 degrees C above 20th century average, poly2 = 2.2, poly3 = 1.1 and exponential = totally off the scale. These results illustrate a few important points: 1. Choice of time period (50 or 100 years) made an enormous difference. Who knows, without modelling the physics, which is correct? Straight line extrapolation from 50 years gave an answer 50% higher than straight line from 100 years. 2. Choice of type of extrapolation also made an enormous difference. Again, who knows, without modelling the physics, which is correct? The best result according to the r^2 value (poly3 - which also looked the best fit by eye), gave an answer way higher than the straight line (8 times), and even poly2 was twice the increase. Here's the take home message. It can be seen that extrapolation as a method gives even wider variation in predictions than modelling does. You've only been able to present it as more stable because you've only used one form of extrapolation that isn't the best according to the r^2, and which contains hidden assumptions about the linearity of processes that are almost certainly wrong. If scientists were to choose just one simpler model, they could get a result that was stable and looked good too, but that would hide the reality just as your simple extrapolation hides the reality. I'll say it again. Extrapolation is a poor method because it doesn't use all the data and it doesn't use any of the physics. It only looks good because you ignore all the possible types of extrapolation and choose the one that contains hidden assumptions that lead to the result that conservatives are looking for. Straight line extrapolation is in a sense a self fulfilling circular argument, and science can do far better than that.
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Post by ignorantianescia on Sept 29, 2016 19:58:18 GMT
I have continued the discussion about the economics of Brexit here. Needless to say I disagree with several additional claims made here since, but I'm not going to respond substantially.
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Post by James Hannam on Oct 6, 2016 8:28:10 GMT
Hi UnkleE,
It seems to me that our argument, and my tangent on economics, has boiled down to when it is right to trust the experts, in other words, when the argument from authority is valid. It is often valid. You brought up the example of the medical profession. I agree with you about that, but 150 years ago it would have been a very bad example since the medical profession had no ability to cure its patients at all and frequently made their condition worse.
We can probably agree that we wouldn’t trust an expert astrologer, psychoanalyst or chiropodist. A child psychologist? Attachment theory remains the mainstream position in this field despite being a sub-Freudian fad that should have died out long ago. The reason it hasn’t is we have no good theory on child development. The most promising, that upbringing is pretty much irrelevant, hasn’t endeared itself to the profession for obvious reasons! A macroeconomist? Maybe we’d disagree on that one.
On climate science, I find your position sensible, mainstream and easily justified from the literature. I don’t agree because I am not satisfied with its empirical track record. I expect we’ll both be getting on a bit before that record has been justified or not.
In practice, this only means that we would order developmental priorities is a slightly different order – as resources are scarce I’d prioritise clean water, cheap electricity and preventive health over climate change. You might juggle the order. You might also say I prioritise today’s problems over tomorrow’s.
Best wishes
James
PS: Thank you for digging up my 2007 words to show I’ve changed my mind. It’s a relief as I’ve been trying to do it more often. It is becoming clear (see the work of Tetlock in particular), that people who change their minds often (foxes) are more likely to be right than the hedgehogs who stick to their theoretical guns come hell or high water. But admitting to yourself that you are wrong can be hard and it is nice to see I can make a bit of progress in this direction.
PPS: Yes, on curve fitting you can always find a curve to fit and the higher the order of polynomial, the more easily you can do it. So, I think you have to assume a straight line fit unless you have solid reasons for believing otherwise.
PPPS: I'm think we have got as far as we can with this. I'll be back when I've changed my mind again....
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Post by unkleE on Oct 7, 2016 8:25:35 GMT
On climate science, I find your position sensible, mainstream and easily justified from the literature. I don’t agree because I am not satisfied with its empirical track record. I expect we’ll both be getting on a bit before that record has been justified or not. Hi James, The predictions are all heading in the same direction and the range of possible outcomes varies from bad to catastrophic. Any inaccuracy within that range is not a good reason to be suspicious about the broad result. Climate science is a hard science which you have little expertise in (as far as I know - I think you studied physics, but not an aspect of physics that is highly relevant to climate science?). So you are backing your judgment against the data, models and expertise of thousands of climate scientists. Granted the potential for disaster, I find this an amazing choice. As I said, the risks are enormous. And the costs of acting are reducing all the time. I have seen one estimate (by someone doing a PhD in the sociology of climate change) that suggests we only need 1-2% of global GDP to take effective action. If that is anywhere near true, it's a no-brainer. We take out life, health, car, house, etc, insurance, why not climate insurance? Granted how much we in the west spend on armaments (another, very expensive, form of insurance - surely climate change is a better investment than that?), gambling, junk food, entertainment, etc, this is a very small and worthwhile investment. We can do both. And climate change is already today's problem. The insurers know it (I can give references). We are paying a cost already, but it is often the poorest countries that are paying the worst cost. Yes, I agree. The fact that you are such a thoughtful and honest person makes it so much harder for me to understand why you don't accept the science, and why you can't see that the cost is relatively small for the enormous risk. No this assumption is demonstrably wrong. The curve doesn't look like a straight line unless you start it at the "right" point. And the method is demonstrably wrong, because (1) we shouldn't be doing this by curve fitting (which doesn't understand the physics), and (2) we DO have solid reasons for not using a straight line - we have scores of models which DO understand the physics. I say "demonstrably" because I believe my previous two comments showed and explained the folly and unreasonableness of a straight line extrapolation. I honestly can't believe you would say this again after that. Yes, I'm happy to finish up. And I can only hope! Thanks.
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jonkon
Master of the Arts
Posts: 111
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Post by jonkon on Oct 7, 2016 15:52:15 GMT
With the current annual GDP growth rate at an anemic 1-2%, your estimate of the cost of controlling climate change would kill all economic growth for the foreseeable future. This is an appalling cost for efforts that have no legitimate scientific basis for actually alleviating a physical phenomenon that is well within the measurement error of available instruments. I have 30 years intimate knowledge and practical experience with the relevant physical phenomena. Climate change advocates are clueless about the basic physics of a green house, the distinction between radiant and thermal energy, and the distinction between and relative strengths and application of behavioral versus structural modeling. "Green house gasses" have no relevance in the inter-conversion of radiant and thermal energy via the Stephan-Boltzmann Law. A Black Body radiator is modeled by a hole in an enclosure - no "green house" gas necessary. Dalton's Law of Partial Pressure means that thermal energy is apportioned proportionately to the relative concentration of the constituent gas - any distinction between "green house" or non-green house gas is irrelevant. Because of the temperature dependence of the solubility constant of "green house gasses" in ocean water - a major mechanism for transporting CO2 out of the body through the blood stream, a positive feedback system would be introduced if climate change proponents were correct about "green house" gas emissions increasing earth's temperature. This system would be unstable and would quickly go into saturation, rendering the earth incapable of supporting life.
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Post by ignorantianescia on Oct 7, 2016 16:21:17 GMT
I was going to say that I find it very interesting that linear extrapolations feel more natural - though I agree that the empirically right thing to do is to use the relations implied by scienfici modelling. I wonder if this resorting to linearity is a common habit (I certainly first check for linear relations myself) and what that says about human psychology. With the current annual GDP growth rate at an anemic 1-2%, your estimate of the cost of controlling climate change would kill all economic growth for the foreseeable future. This is an appalling cost for efforts that have no legitimate scientific basis for actually alleviating a physical phenomenon that is well within the measurement error of available instruments. No, if making the transition to prevent excessive climate change (not sure whether that means 1.5 or 2 degrees centrigade increase this century) would cost 0.02 of global GDP (I'm not going to suggest we should now accept this figure), and global GDP grows with a factor of 1.01 to 1.02 annually, getting the transition done in a reasonable gradual way isn't going to kill all economic growth. Even if all of world GDP would be poured on it until the job is done, that figure suggests one or two years of no growth. I know countries that would have settled for that kind of deal. That's not to mention that the reason growth has been so dismal in most Western countries is in no small part because of the counter-cyclical policies enacted in them (so a fiscal stimulus or even doing nothing would get a better recovery there), and all of that even ignores that changing to renewable energy sources is a very productive innovation that creates more jobs than their fossil-fuel counterparts.
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Post by unkleE on Oct 8, 2016 0:53:07 GMT
With the current annual GDP growth rate at an anemic 1-2%, your estimate of the cost of controlling climate change would kill all economic growth for the foreseeable future. I'm not an economist, but I don't think that's a correct assessment, for several reasons. 1. Whether the climate is changing disastrously or not, temperatures have risen, and this is already having an adverse economic effect (see also this report). Further changes in temperature and rainfall, even if not disastrous, will harm Asian economies and African economies. 2. Economic predictions are for further economic loss due to climate change ( Nature, Forbes, The Conversation). There is a range of opinion on this, e.g. this 2009 Yale paper argues that even the worst effects won't change overall economic growth much, but the mitigation costs won't be great either - but this is now an old paper, while this more recent paper sees severe economic consequences. The effect is worst in poorer countries (also this paper). 3. UK insurer Lloyd’s has accepted the reality of increased catastrophic damage because of climate change. 4. The cost of mitigation are not as great as might be feared - perhaps only 1% GDP globally, and can be seen as a reasonable level of insurance. Some say that climate change mitigation with a have a positive economic effect (after all, economic growth is all about money moving around), but others say that we don't want continued economic growth because the earth can't sustain it. It may be that in Australia at least, climate mitigation and economic growth can both be achieved. So we can see that there is a range of opinion about how economically important climate change is, but it does seem that mitigation won't be too costly, because we would continue the same level of economic growth, just spend the money in slightly different areas. These are some pretty strong statements, so perhaps before I respond can I make sure I understand what you are saying. (1) Are you saying that all those thousands of climate scientists don't understand the system they are studying at all, but you do? (2) Can you outline please your background in climate science or other relevant physics so we can asses your statements here? Thanks.
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jonkon
Master of the Arts
Posts: 111
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Post by jonkon on Oct 9, 2016 2:27:48 GMT
Besides designing many of the instruments climatologists rely upon for their own work, you will have seen my designs in medical dramas and the Bat Cave. Several of my commercially successful blood gas monitors employed IR spectroscopy to determine expired CO2 concentrations.
As for my expertise in economics, each design begins by writing what is essentially a business plan detailing the target audience, its size, competing products, and a list of features and benefits detailing why the customer would want to buy t0his particular proposed product and how exactly the proposed product meets the customer's needs. It concludes with a return on investment calculation based on the projected development costs and revenue. However expertise in economics is not necessary to realize that ANY expenditure to alleviate climate change will hurt the economy, if the mitigating efforts have no effect.
Since one of my responsibilities was the reliability and safety assessment of the products produced by my employer, my duty was to regard professional colleagues as incompetent jerks. It is common knowledge in industry, as well documented by the phrase "3-5 years experience required" in engineering employment adds, that formal science education is largely irrelevant to the practical knowledge needed to design safe, reliable products. General Electric established the ABC Course to bridge this gap. Bernie Gordon, founder of Analogic Corporation, offered to endow a chair at MIT devoted to the more practical aspects of product design - namely introducing a product on schedule, within budget, and meeting specifications - but was turned down because it "did not fall within the scope of our activities." The late Jim Williams, staff scientist at Linear Technology, proudly boasted at his design seminars of his formal training consisting of a semester as a psych major. His counterpart at National Semiconductor, the late Bob Pease, acknowledged the pathetic state of science education, but regarded it as merely enhancing his own job security. While I have a Master's in Biomedical Engineering, I had to learn my craft on the production floor trying to understand why products that worked in the lab failed in the field. I found that I had to systematically go to the source documents in the history of the development of science to uncover the subtleties missed in science texts.
The problem with formal education begins in antiquity with the distinction between "liberal arts" - the education of the free men - and "mechanical arts" - the education of slaves. This led to a general lack of relevance of formal education to practical knowledge, reflected in the attitude of the liberal arts being "mental discipline" as well as the dismissal of engineering as "merely" applied science. The problem was further complicated by the formal "hands-on" science curriculum being determined by the entertainment value of the demonstration experiments rather than their scientific merits. Thus, because of the dramatic nature of its demonstration experiments, electromagnetism was fully accepted into mathematical physics some fifty years before Coulomb established a mathematical basis with his inverse square law of electrostatic attraction, based on 6 measurements that could not be duplicated.
A final problem confronting science education is the refusal of educators to acknowledge the role of Christian theology in fusing, through the example of Christ as True God and True Man, the empiricism of Aristotle with the idealism of Plato, making modern science possible. Thus in science we have the distinction between "theory" - expressed in terms of mathematical formulas - and "observation" - expressed as Scientific Law - as well as between "behavioral" (empirical) and "structural" (theoretical) models. While distinct, the empirical and theoretical are both essential for proper understanding of physical phenomena because of Godel's Incompleteness Theorem. Godel's Theorem requires two levels of knowledge to completely specify a system, thus an empirical relationship must have a theoretical basis to be valid, while a theory in turn must be supported by observation. Likewise they deny the essential role of expeditious "assumptions" in the scientific analysis of physical phenomena, to avoid the reality that all scientific knowledge is ultimately accepted on faith. Scientific progress is achieved by uncovering implicit assumptions and testing their validity.
Relating back to the issue of climate change, empirical relationships, without theoretical foundation, can be influenced by hidden factors. Thus is the observed increase in temperature in fact caused by increased urbanization around the airports where the measurements are being taken? Secondly, is the complexity of the theoretical models obscuring the fact that there is no physical relationship whereby increases in greenhouse gases cause an increase in atmospheric temperature? To establish "causality" there must be a deductive chain of reasoning whereby an increase in greenhouse gases results in an increase in atmospheric temperature. The conventional explanation of greenhouse gases "storing" radiant energy is wrong on several points. "Radiant" as opposed to "thermal" energy is in the form of photons. These photons strike the greenhouse gas molecule, causing increased vibration among the C-O bonds. Since these vibrations are along a line of symmetry in the molecule, they cannot affect the translational motion comprising the molecule's thermal energy. Instead radiant energy is absorbed and re-emitted as photons without any loss of energy. Radiant energy instead is converted into thermal energy in accord with Stephan-Boltzman Law, with the earth's surface acting as the black body. This thermal energy, because of Dalton's Law of Partial Pressure, is apportioned according to the relative concentration of gas molecules, irrespective of the species of gas.
The observed relationship between greenhouse gas concentration and temperature level, likewise confuses cause with effect because of an inadequate understanding of the mechanism involved. CO2 is readily absorbed by the water in the oceans, and in turn is precipitated out as dolomite and limestone. The solubility constants are temperature dependent so that an increase in temperature CAUSES an increase in atmospheric CO2 levels.
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