Global warming discussion

Page first edition 15/02/2009, last updated 12/11/2013.

Discussion

Tony; I notice that you refer to Carbon Dioxide as a Pollutant. This is something that Sceptics vigorously resist, saying it is a natural gas, colourless, odourless and not a pollutant.

Reply; My definition of a pollutant is any chemical that is around in a concentration high enough to do damage. Any chemical can be a pollutant! Any chemical in low enough concentrations is not a pollutant. This point needs stressing because there is too much talk of chemical A being OK while chemical B is toxic which leads to incorrect conclusions. It is usually just a case of nature having adapted to having more of A around than B. Talking of "toxicity" without also talking about appropriate concentration levels has caused enormous wasted effort and angst as people try to eliminate chemicals just because they have been labelled toxic. There are millions of chemicals existing in the bodies of animals and plants, and in nature, and every one of them needs to be in the right place and in the right concentration to do its job properly. In our bodies CO₂ is present primarily in our lungs and blood and we are in trouble if the concentration goes too high, or too low. It is all about balance in our bodies as well as in the air we all have to breath. CO₂ has recently become a pollutant because we have put too much into the air.

Tony; Nearly all Sceptic scientists rebut computer models. Why? Because it is simply impossible to enter all the data, and it is too easy to cherry-pick, so the result is not science but politics.

Reply; There is indeed a sad history of modellers making "convenient" simplifications because it is true that not every factor can be taken into account. That is why it is important to follow the money trail because knowing who funded a piece of work usually reveals clues about its bias. However, computer models are now enabling us to make huge technological leaps. These days cars, aircraft , computers etc., are all designed with a critical reliance on computer models. The programmers have refined their computer code to the point that it is easy to use and gives accurate results. Real physical prototypes are still built to refine the details and test new features but the computer is now essential in advancing most areas of science and engineering. It is no different with climate modelling. The climate models in the 70's and 80's made many simplifying assumptions and were criticised for it. Their predictions were nevertheless alarming enough to make other scientists take the results very seriously and huge amounts of work were done to refine the models. Numerous extremely sophisticated experiments were also done on Earth and in Space to measure anything that could possibly be important to the issue. Still the sceptics were not happy so very little was done to fix GW. Over 30 years was wasted because oil prices were low. (The oil crisis of the 1970's caused a spurt in developing clean energy systems. The oil exporting countries probably saw this progress and realised that they needed to keep prices low or else they would loose their market. Governments also banned research funding for some of the most promising areas. However, now in 2011 the cheap oil is running out so prices cannot be kept low any more.) One of the predictions from early models was more extreme weather events. Thirty or more years of studying but not fixing the GW problem has seen exactly this happen. The cost of the extra damage done would have paid for huge research programs into solar, wind, wave and other clean renewable energy sources. Every fossil fuelled power station being built today is drawing funds away from clean energy production and increasing the cost of fixing the problem of global warming gases when we finally have sufficient consensus about it being a problem.

It is a tragic fact of modern culture that lying, deception and falsification of reports is close to becoming the accepted norm. People do not know who to believe so vast amounts of time are wasted double checking things and exposing dishonesty. Having reviewed some of the global warming sceptic links you refer to I can see so much dishonesty in them it makes it hard to stick with it and make a full review. I am not saying some of the greens have been much better but there is no excuse for lying; it just delays meaningful progress.

Tony; Perhaps you would oblige me by telling me what precisely are your qualifications.

Reply; Blowing my own trumpet is something I am extremely uncomfortable with but since it seems to be so important to you I will explain why I feel qualified to comment on the global warming debate. I qualified as a Chemical Engineer (BSc and then MSc) at the University of Cape Town (UCT). I am proud of this because the standard was as high as anywhere in the world. I am in a good position to judge this because I have worked for 6 years at the University of Cambridge which was recently assessed as the best in the world. At UCT they kept the standard high by failing about half the original intake. In South Africa engineers have a far higher status than they do in the UK and my year attracted the best students in the whole of Southern Africa. In the UK I gained my PhD at Middlesex University. I then moved to Keele and then Cambridge and in both I was working directly for a Fellow of the Royal Society. The Royal Society has by far the most prestigious fellowship. I am not a professor because I have preferred to do practical hands-on research rather than lecture. I am not a fellow of any organisation because chasing labels is not my game.

Chemical Engineering arose because of the need to design complex chemical plants which have to be right first time. A large plant costs a huge amount to build and getting the design wrong can be extremely expensive to rectify. In these plants chemicals frequently have to be heated and cooled and reactions occur that make it very difficult to predict what temperature will be achieved in different parts of the process. We therefore spend a large part of our time looking at various heat transfer processes and making sure our mathematical models of temperature profiles are as accurate as possible. This is all very similar to climate modelling. In fact I propose that Chemical Engineers are better qualified to do climate modelling than any other profession.

Tony; There is no such thing as world climate – it just does not exist. But there is climate in regions. In all seriousness, otherwise seemingly intelligent men believe that by cutting back on the minuscule amount of Carbon Dioxide produced by man, that somehow or other they will affect the weather and the climate. Did I say the weather? Yes, I did, for they define climate as an average of weather, not my definition, theirs!

Reply; Think of the climate as a sort of envelope in which the weather operates. Within that envelope there is a probability that certain weather conditions will occur at different times of the year. Climate modellers divide the world into small sections and model the weather probabilities in each little section. To predict a global average temperature at a certain time they first predict the average temperature in each little area and then take another average. As computers become faster and as the data for the models becomes more accurate the accuracy of these models increases. In 1896 Arrhenius estimated that a doubling of CO₂ would cause a temperature rise of 5 to 6 °C using manual calculations with crude data. Modern but very conservative estimates by the IPCC are 2 to 4.5 °C. The physics of the infra red absorption properties of CO₂ that make it a green house gas cannot be disputed and the fact that humanity is producing enough to make a difference to the weather is beyond doubt. The danger to life comes from the extremes of the envelope. As CO₂ levels rise the probability of extreme temperature events and storms and droughts increase and these events cause huge economic damage. The cost of changing to non-polluting renewable energy generation would be less.

Tony; 600,000 years ago so I am lead to believe, the white cliffs of Dover were joined to the white cliffs of Normandy.

Reply; Besides evidence of large swings in the global temperature and CO₂ levels every 100 000 years or so there is also evidence of large swings in sea level. In an ice age huge volumes of ice collect at the poles and sea level drops many meters. A lower sea level might sound convenient but the low temperatures would be very inconvenient. England has been covered by glaciers many times. Human activity has made that very unlikely for a very long time but we are in danger of going too far the other way producing tragic flooding of vast areas of low land.

The cause of the cooling in the 100 000 year cycle is a very subtle feature of the Earth's orbit that puts it further from the Sun during the Northern hemisphere spring and summer. The cooler sea dissolves more CO₂ so very slowly over many centuries the atmospheric CO₂ level drops and this results in less global warming so the temperature drops even more. As the earth moves towards the Sun again in the next part of the cycle the sea releases some of the extra CO₂ it dissolved before and again a positive feedback occurs. This would explain why CO₂ level changes appear to lag temperature changes.

Doug; ... Ice floats and ice insulates, preventing the water below from cooling. Melting ice lets the water below cool. That is what causes the multidecadal oscillations. The ice PREVENTS the water below from cooling. Without the ice, the water evaporates and cools and radiates its heat out into space. Then when the water is sufficiently COOLED, the ice reforms. This is a ~30 year cycle. This has been well-known for many decades. So your runaway sea ice melt scenario is unfounded. ...

Reply; There are a number of cyclical variations within the oceans, some of them taking many decades to complete. This complicates prediction of the weather but does not have a big effect on climate modelling. It certainly gets nowhere near weakening the theory that global warming is a serious danger. The fact remains that we are loosing ice coverage from the planet. Loss of this reflective surface to expose less reflective surfaces underneath means more of the Sun's energy is captured by the planet. Global warming is totally dominated by the radiation that passes through our atmosphere. The emissivity of the surfaces exposed to the Sun and space determines how much energy stays and how much is reflected or radiated away. The heat conductivity of the surface materials makes a minimal difference. Snow and ice are very reflective but sea water captures most of the energy so the melting of the frozen surface layers is a positive feedback mechanism. Positive feedbacks mean we are storing up serious problems for the future. The insulating properties of the ice sheets only affect the local temperatures. It is the light absorption spectrum of CO₂ that makes it a green house gas and the passage of electromagnetic energy through our atmosphere and into space is what determines the average temperature of the planet. More CO₂ means more heat which means less ice which means more rapid heating.

Commentary

www.newscientist.com/article/mg20327151.300-sea-level-rise-its-worse-than-we-thought.html?full=true points out that sea levels rose 17 centimetres in the 20th century and that the rate of rise is increasing. The article goes into detail about recent studies of ice melting and water expansion and analyses likely future sea levels. The news needs to be taken seriously because our population density is greatest near the ocean and an estimated rise of 2 metres by the end of this century is starting to look conservative. This would cause devastating damage to coastal cities.

"How it all ends" by Greg Craven is an excellent video explaining the need to take action. We cannot be totally certain about how much our actions are affecting the climate, but we can decide what to do about the risks. The worst outcome of taking action is that we will waste money and reduce our material wealth. The worst consequence of taking no action is a complete disaster on numerous levels. Craven makes it clear that taking every possible action we can is the only sensible option. He has made a number of other videos to a similar high standard that he calls the expansion pack. God's will is recommended. He has recently released a book that should be well worth reading if it is up to the standard of his videos; What's the Worst That Could Happen?

Stephen Wilde has written a series of articles about climate. Here I am specifically commenting on Global Warming and Cooling - The Reality and The hot water bottle effect. Like most who question the importance of humanity's affect on the climate Wilde seems to dismiss the importance of mathematical modelling. What they do not seem to realise is that computer models are now extremely important tools that are indispensable for so many things we now take for granted. One quick example. In the days of communism in the Eastern block they did not have many computers so they designed their cars with slide rules and educated judgement. In the West cars have been designed using computer models for many years now. It is the countless billions of calculations done by the computers that allowed the cars made in the West to be so much better than those made in the Eastern block. In Wilde's articles he spends a lot of time stating facts that climate modellers are well aware of. The trouble is he does not appear to have done the sums so his judgement about what is important and what is not is poor. Climate modelling is about dividing the world up into thousands of blocks and then doing millions of sums about the climate in each block. By dividing the world up in such a way it is possible to get a more accurate overview of how the different factors influence each other. This cannot be done without a computer model. I have frequently been surprised at the results that came out of my computer models, but these unexpected results were usually shown to be correct when verified by real-world experiments. Until Wilde demonstrates a good understanding of numerical climate modelling, and has done some sums, I will have trouble respecting his opinions.

Open source model idea

Something that would be most useful would be an open source climate model that the public could run on their own computers. I have not done an exhaustive search so maybe such a thing exists already. Please let me know if there is one and I will put a link here. Such a program would allow people to see what is already included in the model. If their favourite system is left out they could try adding it and seeing what difference it makes.

www.co2science.org/ is a site with a huge amount of data which appears to me to have been cherry picked to disprove GW. For instance they have a database of American weather stations; thousands of them. You can pick them one at a time and they claim that on average you will see that there has been no net temperature increase since 1930. Well I picked 2 at random and they both showed a distinct temperature rise. This is a ploy used by many GW sceptic sites: - distract you with a mountain of data so that you have less time to study the bigger picture. I also picked an area from the Global Historical Climatology Network data set that roughly represented Africa since 1880. Again, a clear and steady(ish) rise in temperature was reported. From the Medieval Warm Period Project data set I again chose 2 examples at random. One suggested higher temperatures in medieval times than now and the other suggested it was cooler, but both showed an increase during the 20th century. How far do we want it to increase? The site also claims that more water in the atmosphere will cause more clouds which will reflect the sun's heat away from the earth. Well that might be true but cloud formation is complex and to my knowledge it is not yet certain if this is true. What is know for certain is that hotter air holds more water as a vapour invisible to the light our eyes can see but not in the infra-red. This will cause more GW; for certain. They also go into details about how to do an experiment that shows how a plant grows faster as the concentration of CO₂ rises and as temperature rises. Did they think professional biologists who study GW did not know this? Plants in the real world have to contend with more than just CO₂ and temperature rises. The spread of pests is one important factor this site seems to have neglected. In conclusion there is an impressive amount of data on this site but I do not trust it because there appears to be a strong bias in what they choose to highlight.

On October 16th, 2009 Adam Axvig posted a talk by Lord Christopher Monckton on www.mnfmi.org/ There is a slide show that goes with it that is important to download to follow everything being said. It starts off by stressing the importance of truth but unfortunately very quickly fails to follow its own guidelines. Monckton is extremely well informed so he has a mass of evidence about the faults with what has been said about global warming. There is no excuse for these faults because it enables AGW sceptics like Monckton to spin a story that plays into the hands of those wishing to continue making money from fossil fuels. By stressing the importance of truth he seems to be hoping to dull his audience's critical faculties and maybe prevent them noticing his own distortions. I don't make that accusation lightly but I know for a fact that what he says about the weakness of computer models is biased. He also falls for the classic AGW sceptic line of claiming that the concentration of CO₂ in the atmosphere is so small that it cannot make any difference. When it was discovered that tiny amounts of chlorofluorocarbons (CFC) in the air were causing a hole in the ozone layer decisive action was quickly taken. This was because the value of the CFC industry was not too big and alternatives were developed. The concentrations involved are more than 100 000 times lower than the concentration of CO₂ that is causing concern.

The problem with CO₂ is that the industries that put it into the atmosphere are absolutely huge and the alternatives are seen as inconvenient. They need not be, and Monckton has totally failed to see that. When he warns at the end of the talk about an imminent treaty to form a global government I am left wondering whether to believe him and get worried, or maybe he is trying to mislead us again. Taking the wrong action to combat AGW is just as bad as denying its danger in the first place. Monckton correctly states that the truth must dominate but his talk contained too much that I know to be wrong so I have trouble believing most other things he says.

One example. He said he had reviewed an impressively large number of papers about climate change and checked to see how many mentioned the Stefan–Boltzmann equation and found that none did. His implication was that the authors of these papers had not been aware of this equation and therefore their work was suspect. If you do not know about this equation it is hard to explain how naughty Monckton was to do this. The Stefan–Boltzmann equation is at the core of climate modelling and everyone in the field will be so familiar with it that there will rarely be a need to mention it. It is a simple equation and the only part of it that needs further study from climate modellers is the emissivity of surfaces. If Monckton had scanned for "emissivity" in all those papers he would have found a ton of references but that would have disproved his case so instead he chose to mislead those in the audience without sufficient background in the subject to see through his dishonesty.

In my next essay I explain that good science is essentially honest observation; Scientific method