Monday 10 December 2018

Is CO2 the most maligned gas in history?

The mining industry is one of the world's greatest emitters of carbon dioxide, and legislation to reduce emissions has a severe impact not only on existing operations but on the potential start up of new ventures. And all at a time when the demand for metals is growing, particularly with the electric vehicle revolution.
It is not surprising, therefore, that talk at major mineral processing conferences often drifts towards climate change and its causes. Mineral processors are not climate change scientists but they are entitled to their views. As is the veteran broadcaster Sir David Attenborough, who last week was the keynote speaker at the opening ceremony of the United Nations-sponsored climate talks in Katowice, Poland, the most critical meeting on climate change since the 2015 Paris agreement.
Sir David painted a truly apocalyptic vision of the future with the collapse of civilisations and the extinction of "much of the natural world".  "Right now," he said "we are facing a man-made disaster of global scale. Our greatest threat in thousands of years. Climate change". He urged everyone to change their habits, in particular avoiding air travel- a little hypocritical maybe, as he spends half his life in the air travelling to remote locations for his excellent natural history series.
Sir David's comments were the lead story on the BBC national news that evening. Not surprising as his views reflect the BBC's hard-line policy, an article in The Times (BBC freezes out climate change sceptics, September 8th 2018) reporting that science staff have been told that they need no longer invite those who deny anthropogenic global warming on its programmes, suggesting that allowing them to speak was "like letting someone deny last week's football scores". It is very noticeable that the BBC's references to climate change are almost always preceded by 'man-made', but what really angers me is the repeated assertion that "all scientists agree that climate change is due to the activities of man".
This is just not true. When I discuss the topic at conferences there are, of course, many who back anthropogenic warming, but there are many who are sceptics who question some, or much, of the science. Many, however, are outright deniers of man-made climate change and feel that it is more likely that the temperature rise is due to natural cycles. Geologists in particular tend to support this, claiming that they have seen it all before, although not literally, and some astrophysicists argue that the temperature rise is due to solar activity.
There was much intense debate on the blog a few years ago, and a very eminent geologist, Prof. Ian Plimer, Emeritus Professor of the University of Melbourne, presented some very convincing arguments against anthropogenic global warming, which led to some interesting comments, and a long response against his arguments by the University of Exeter's Dr. Stephan Harrison. Many geologists that I speak to support Plimer's views.
So where do I stand on this extremely complex topic? I have spent almost 40% of my life as an editor of a peer-reviewed journal and have developed a nose for sniffing out bad science and I have to admit that I have been very sceptical about some of the science advocating anthropogenic global warming. I am a great believer in the motto of the Royal Society, nullius in verba (take nobody's word for it) and believe that all scientists should question the work of others even though they may not be directly involved in that field.
If pushed I would take the view that climate change is mainly a natural phenomenon, to which we humans contribute but by how much nobody knows. The suggestion that a small increase in concentration of a trace gas in the atmosphere can have such a profound effect on climate, and on the acidification of the oceans, leading to the disappearance of coral reefs, is not easy for me to accept. The media regularly report that CO2 levels have increased by around 40% since pre-industrial times, and the temperature has risen by 0.8 C. A question that I have asked before, but have not really got a satisfactory answer to, is 'how do we know this'? How can we compare temperatures and CO2 levels now to those of pre-industrial times when there was then no real interest in these levels?
An increase in 40% seems a lot, but in absolute terms this is an increase in concentration from just under 0.03% to the present level of just over 0.04%. Can this small increase have such a profound effect? Many scientists are convinced that it can, as the Danish electrochemist Arrhenius showed in the early 20th century that without the greenhouse gases H2O, CO2, CH4, O3 and N2O, the surface of the earth would be about -20C , like the moon. In this complex mix CO2 is the gas which has the second largest impact on reducing the amount of long wavelength radiation emitted by the earth, warmed by the Sun, back to space. The most potent green-house gas is water vapour and rising temperatures increase the amount of this gas in the atmosphere. Other major green-house gases are hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride. These are synthetic, powerful greenhouse gases that are emitted from a variety of industrial processes. They are typically emitted in smaller quantities than CO2, but because they are powerful greenhouse gases, they are sometimes referred to as High Global Warming Potential gases.
But suppose Plimer is right, and temperature rise is part of a natural cycle. The oceans contain trillions of tonnes of CO2 and a rise in temperature must, according to Henry's Law, release CO2 into the atmosphere, explaining the correlation between temperature and CO2 levels, the argument behind the climate change debate. The CO2 level would then be expected to lag behind the temperature rise, and there have been many articles in reputable journals over the past decade saying just this, although there have not been many reports of this in the media. So, does temperature drive CO2 levels, and not the other way round? Or maybe it is a combination of both?
What I find really hard to swallow, however, is that an increase in CO2 concentration from 0.03% to 0.04% can acidify the oceans to such an extent that Sir David Attenborough predicted in his superb series, The Blue Planet, that the coral reefs would disappear by the end of the century. The programme even had a ludicrous demonstration of this, showing that when acid was poured onto a piece of coral it bubbled and fizzed- of course it would.
Carbonic acid is one of the weakest of acids, but even so, an increase in ocean temperature must release CO2, so if indeed the rate of attack on the coral reefs is increasing, what is causing it? Well every hydrometallurgist knows that the rate of leaching increases not only with acid concentration, but also with temperature.
So back to my eponymous question. Is CO2 the most maligned gas in history? It is present in trace amounts in the atmosphere, it is not a pollutant and is essential for plant growth and the production of oxygen.
Is the emphasis on CO2 taking the pressure off the real killer in the atmosphere? Air pollution is one of the world's major causes of death, and one of the main culprits is NO2 in internal combustion engine emissions. Electric vehicles will play a major role in the reduction of such emissions, and the mining industry will be vital in producing the materials for these vehicles. Let's hope that it is not hamstrung by the need to spend billions on controlling its own CO2 emissions. Mining is the primary industry, which feeds all other industries, and without a thriving mining industry civilisations would indeed collapse. So if draconian cuts in emissions are imposed, maybe it could be considered as a special case? Very unlikely I would suspect.
I am expecting a bit of flak by publishing this post, but it is basically to solicit your views on this controversial subject. Do you believe that climate change is solely down to human activity, is it a purely natural phenomenon, or do you feel that it is probably a combination of both?
Twitter @barrywills

16 comments:

  1. Good to read your narrative. Since I am closely involved on coal, I also feel the same way you feel whenever I attend some of the conferences on coal and its utilisation and emissions.
    It surprises me and I even took all my courage to ask in public on why scientists and engineers have not come up with an economical system to break CO2 into carbon and oxygen---I get the standard answer that it is expensive. For me we should make the process technically feasible and then make it economically viable.
    Barry, I might not have got the things right but I am happy that MEI has raised issues related to emissions from processes.
    Rao,T.C.

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    1. Thanks for your input TC. As CO2 is a potent green-house gas, the burning of coal and other fossil fuels must have an input to the warming of the planet. The question is to what degree? Are there other forces at work, including natural cycles? Is man's contribution miniscule compared to these? Basically no one knows. But if we stop asking questions and assume that the debate is over, then we will never know.

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    2. Splitting carbon dioxide (CO2) into carbon and oxygen can in fact be accomplished, but there is a catch: doing so requires energy. If hydrocarbon fuels, which produce the greenhouse gas in the first place, supply that energy, thermodynamics tells us that the net result will be more CO2 than you started with.

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  2. All engineers have a position on climate change, man-made or natural causation it is good practice to reduce energy consumption and utilise renewable energy generation where practicable and I believe our industry is contributing. I recall MEI were going to put on a Conference on Global Warming as it was then called some years ago when the subject was in its early stages and discussions were very lively to say the least. I registered for it but Barry decided not to go ahead with the event - Too hot to handle?

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    1. Hi Tony. Thanks for your comments. Yes we did intend to run a conference on Climate Change and the Minerals Industry seven years ago, but for various reasons decided not to go ahead. See the posting of 10th February 2010. As you so rightly point out, we can do a lot by reducing energy consumption, and the ways that we can do this are now incorporated into all MEI Conferences.

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  3. Humans have, though, have easily added enough carbon dioxide into the atmosphere to account for the recent rise in CO2 levels. In the last hundred years humans have emitted about 2 trillion tons of CO2. The total mass of the atmosphere is about 5000 trillion tons of which about 3 trillion tons is CO2 (CO2 is about 0.06% of the atmosphere on a mass basis). This means that the human addition of CO2 to the atmosphere is substantially greater than the increase in CO2 levels in the atmosphere (the increase has been about 0.7 trillion tons compared to the 2 trillion tons that humans have added). If we take the ocean and atmosphere as a single couple system then the human addition into this system over the last 100 years is substantially more than an order of magnitude greater than the contribution from geological sources. While it is true that there are natural cycles in CO2 levels, the increase associated with the current cycle is more than twice as big as that of any other cycle in CO2 levels in the last 2 million years (and there have been a lot of cycles in that time), with the last time that CO2 levels were this high being about 5 million years ago (when the climate was a lot warmer than now). All of this on its own is not proof that humans are responsible for the increase over the last 100 years, but it is by far the most likely explanation.

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    1. For some reason this put me down as Unknown. Stephen Neethling

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    2. Thanks for this Stephen. Estimating how much CO2 we have actually emitted, and how much remains in the atmosphere is a difficult one. One of the questions that I asked in the posting of 11th February 2014 was how are a country's emissions measured, or calculated, and the answers were not that convincing.

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    3. Hi Stephen. Could you advise where you get your figures from, as you seem to imply that the current CO2 content in the atmosphere is 600 ppm and not 400ppm?
      Jacob Hearst, Phoenix, AZ

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  4. MEI poses a rhetorical question “Is CO2 the most maligned gas in history?”, and states that “climate change is mainly a natural phenomenon, to which we humans contribute but by how much nobody knows”. If I were raising cattle, I might ask “Is methane the most maligned gas in history?” In my opinion, just as the extent to which we use fossil fuels, the extent to which we raise cattle (the major source of “anthropogenic” methane) also is not sustainable. And if I were to complete the logical space of the statement it would go: “climate change is mainly a natural phenomenon, but by how much nobody knows.” However, there is nothing we can do about a geological cycle.
    The Intergovernmental Panel on Climate Change determined that atmospheric CO2 concentrations have increased steadily since the beginning of the industrial era, from an annual average of 280 parts per million in the late 1700s to 401 ppm in 2015 – a 43% increase over 250 years (a drop in the bucket by the standards of geological time), almost all of which is due to human activities. Analysis by the World Resources Institute indicates that actual CO2 emissions globally were 150 times higher in 2011 than they were in 1850. Numerous studies indicate that these trends are primarily due to fossil fuel emissions, a conclusion that has clearly met global scientific consensus (keeping in mind that consensus never implies complete agreement).
    All this said, the quantitative aspects of the debate are not the most important issues. In my view, the issue is not whether one or other perspective is right or wrong, or even how much of one or other is right or wrong. More important are the implications of being right or wrong, and the age-old relationships between truth, action and consequences. And on this the proponents of anthropogenic global warming are winning the debate in my view: the projected consequences are highly significant for the future of many species.
    The mineral industry does not have a stellar reputation regarding the environment and the public perceptions of its role in this. It is therefore important for the industry to be on the right side of the issues: to be perceived as integral to solutions, not part of the problem. Taking effective action on the anthropogenic contribution to climate change should be seen as a win-win opportunity for the mineral sciences. MEI’s reference to electric vehicles represents only one of a vast number of attractive and feasible solutions.

    Congratulations on an engaging blog incidentally! Franklin White

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    1. Great points, Franklin, many thanks. The mining industry is one of the world's greatest consumers of energy, and so by definition one of the world's greatest emitters of CO2. Although the contribution between anthropogenic and natural cycles cannot be quantified, the industry must be contributing to global warming to some extent and so every effort must be made to reduce this contribution. As Tony Francis rightly points out, its is good practice anyway to reduce energy consumption purely on economic grounds, and tremendous efforts are being made to do just this, as is evident from presentations at all major minerals conferences around the world.

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  5. I eagerly wait for the deliberations in the Conference---enough is known on what is happening. Now the next step has to be to find short term and long term solutions.
    When one gets a headache, we will not think of cutting the head but find the causes and solutions which are implementable so that we can cater to the hunger of energy requirements.
    Rao,T.C.

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  6. My comments of 13th December are more out of my complete ignorance of total picture--which activity is causing what and how much damage which is le leading towards to global warming. Coal is maligned too much and so I feel MEI taking a lead is very welcome.
    Please take my remark on" chopping off the head" as coming from a person with limited(confused)knowledge on these matters.
    By innovation, we made see water drinkable, mission to mars and moon and so I am sure we will find a solution if complex problem like global warming is broken into simple subproblems,and take good control of forests(trees),ground water and beaches etc , science will come to our rescue.
    I hope solutions will emerge for each part of the total problem
    Rao,T.C.

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    1. TC, as I said in the posting, humans must play some part in climate change, but we do not know to what extent. Fossil fuels, particularly coal must have an effect, so it makes good sense to phase them out when possible. I am not, as you suggest, taking a lead against maligning coal.

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  7. Cement is the source of about 8% of the world's CO2 emissions, according to think tank Chatham House. Cement is the most widely used man-made material in existence. It is second only to water as the most-consumed resource on the planet. But, while cement - the key ingredient in concrete - has shaped much of our built environment, it also has a massive carbon footprint. According to the think tank, if the cement industry were a country, it would be the third largest emitter in the world - behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%).




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