Tuesday 11 February 2014

A few simple questions for climate scientists

Porthleven, Cornwall
A report this week from the UK Met Office warns that the "conveyor belt" of storms which has battered us since early December is likely to last for at least the next few weeks. It suggests that the UK's floods and storms are just one element of a global disruption of weather patterns, the origin of which lies thousands of miles away in the tropical Pacific. According to the report, the changes are consistent with climate change.
Climate change science, and in particular government policies determined by scientific reports, are of great importance to the minerals industry, a major consumer of energy and producer of CO2. It is interesting to read the intense debate which took place on this blog over three years ago,  the overwhelming consensus among the many minerals industry correspondents being that if humans are contributing to climate change, the extent to which they are contributing is open to much doubt and debate.
Since the recent Intergovernmental Panel on Climate Change (IPCC) report the media are again reporting that all scientists agree that climate change is taking place and that there is little doubt that human action is the main contributor via CO2 emissions. I wonder if the correspondents of 3 years ago now fall into line with these views?
Personally I don't want to get embroiled in the debate between climate change believers and deniers again. There appears to be little doubt that climate change is now taking place, and that humans are playing some part in this, but to what extent is still open to debate.
My scepticism has always been about the reliability of models describing this immensely complex system and the IPCC report also casts some doubt on the models and their predictions of what will happen by the end of the century.
The debate is essentially about carbon dioxide levels and temperature, but for me some aspects have never been satisfactorily explained. My questions may be naïve, but if they are simplistic then maybe someone can provide simple answers:

1. It is said that the average temperature of the atmosphere has risen by 1.5 C over the last 100 years. How do we know this? There must be sophisticated methods of measuring the temperature now, but how was average temperature measured 100 years ago?

2. Apparently the CO2 level is now around 400ppm. Is this a global average or is this a uniform figure ie is the CO2 level in the UK the same as that in India and of that over the centre of the Pacific? If it is not uniform is it reliable to compare levels now with levels inferred from CO2 trapped only in Antarctic ice? And would CO2 in this air be dissolved into the ice with time, thus giving falsely low readings?

3. If a country is told to cut its CO2 levels by X%, how does anyone know if they have done this or not? How are a country's emissions measured (or calculated)?

Please help me understand!


  1. Replies
    1. Thanks Amanda. I'm certainly not convinced by this. I have asked many scientists if they can provide a satisfactory answer to my question 1, but I have never had an answer which has come close to convincing me. Can anyone provide a clear answer?

    2. Great questions Barry. What people seem to forget is that our planet has had significantly nasty weather changes in the past that easily overshadow what we are predicting, and there was no human influence then, if CO2 is to blame. This is a question to which I have not had an answer.

    3. Nor me John, but I don't want to go down that path....

    4. The real danger to society is not from CO2 but from those groups who claim the argument is settled and who want to shut down free, open and honest scientific debate. "Consensus" on a hypothesis does not constitute scientific proof. If there were proof it would be written down for all to see. Those of use who follow this debate will also have seen how the reputation of the golden boy of global warming and inventor of the "hockey stick," Micheal Mann, has been completely destroyed in open court when he failed to produce his "evidence." http://www.principia-scientific.org/michael-mann-faces-bankruptcy-as-his-courtroom-climate-capers-collapse.html . Personally I do not doubt there is climate change, the climate has been constantly changing since the formation of the planet, however to say that, higher temperatures, lower temperatures, more snow and blizzards, drought, fire, floods, rising sea levels, disappearing glaciers, loss of sea ice at the poles, species extinction, more and stronger storms, more storm damage, dying forests, death of coral reefs and shellfish, shutting down the Gulf Stream, fatal heat waves, more heat-related illness and disease, crop failure and food shortages, millions of climate change refugees, increased cancer, cardiovascular disease, mental illness, respiratory disease and, a devastating effect on the quality of French wines, can all be attributed to a few ppm change in atmospheric CO2 and no other cause not only stretches the bounds of credulity but is a monstrous distortion of the facts and is patently untrue.

  2. Good Questions Barry- I hope someone has some good answers

  3. 1. It is said that the average temperature of the atmosphere has risen by 1.5 C over the last 100 years. How do we know this? There must be sophisticated methods of measuring the temperature now, but how was average temperature measured 100 years ago?

    Answer: "The temperature data for the record come from measurements from land stations and ships. On land, temperature sensors are kept in a Stevenson screen or a maximum minimum temperature system (MMTS). The sea record consists of surface ships taking sea temperature measurements from engine inlets or buckets."

    1. For this question, even the right answer might not be satisfactory. It seems like it's hard to accurately measure the average global surface temperature, now and more so in the past. From what I read, there is a lot of data "manipulation" needed to arrive at a single global value. By manipulation I don't mean faking the data, as scientists have been previously accused of, but doing mathematical operations like normalization, averaging, outlier elimination, etc.

      As a scientist, I know these approaches are needed when dealing with large data sets and complex problems, and if done right can uncover the data trends, which are sometimes more important than the absolutes values. But it's harder to explain this to the general public, and that's where climate skeptics pounce.

      My feeling is that surface temperature is only one variable that can be affected by the increasing atmospheric CO2 emissions. Ocean temperature is another, atmospheric temperatures gradients another, but also temperature is not the only way energy accumulation is manifested. Extra energy that is trapped in the Earth, due to blocking of greenhouse gases, can also end up as chemically stored energy, and kinetically stored energy, and these accumulations can also be contributing to climate change (I think).

    2. Thanks for this. As I said it's immensely complex and that's where my concerns about modelling creep in

  4. The fact that matters is that extreme weather is taking place in different parts of the globe as we speak. North America has experienced some of the heaviest snowfall on record. It has snowed heavily in Japan, way beyond average records. The UK is experiencing severe storms. As for my home country, this is the hottest and driest summer ever recorded here in Brazil. I do not know whether the climate is changing or not. What I do know is the FACT that the weather is getting more and more extreme in various parts of the globe at the same time. Some say this might be a presage of a major climate change that is waiting for us just around the corner. I leave it to the experts to determine whether the climate is changing or not. Some people don´t believe in coincidence though...

    1. I'm not disputing climate change Pedro. The point of my posting was to seek clarification on certain points regarding the science

    2. I understand your point, Barry. I was just pointing out the undeniable fact that more and more extreme weather is affecting many parts of the globe concomitantly and this may not be just a coincidence. Who knows? This could well be just a transitory situation, or the beginning of a major shift. I do appreciate the complexity of trying to model/predict climate changes where scientists have to deal with so many variables and uncertainties. That´s exactly the reason why I am sticking to the facts only. As I said on my previous comment, I leave it to the experts to try and predict what is going to happen to the climate.

  5. The three or four independent temperature anomaly measurements over about 150 years, used in calculating average land or sea temperatures seem to be in accord with each other and show the greater variability off measurement in the 1850 to 1900 period, as may be expected due to earlier less perfect measurement systems and/or the possibly more limited rigor of their application. It is hard to doubt the validity of these similar values, much like it is not easy to reject points closely describing some plotted relationship on a curve of results that are not doubtful out-rider, or "wild", results.

    We make a lot of decisions in applied science based on relationships that are not anywhere as neat as those presented in the document mentioned by Ms. Wills. While it might be stated that climate change is too important to leave to such doubt, it can equally be argued, and I think more convincingly, that when the consequences of a phenomenon can be irreversible it is not the time to take chances. As humans we cannot (yet) control the long term evolution of natural weather variations, but we can do something collectively, thereby allowing all industries, societies and individuals to at least be on a level playing field.

    A simple question for the questioner: Given the evident transformation of permafrost and release of methane, and the loss of ice cover in the northern waters, what concrete steps do you envisage that might slow or reverse those changes?

    Arthur Plumpton (Linkedin Canada)

    1. I've no idea Arthur. I'm not a climate scientist, and that is why I asked the simple questions, merely for clarification

  6. "Apparently the CO2 level is now around 400ppm. Is this a global average or is this a uniform figure ie is the CO2 level in the UK the same as that in India and of that over the centre of the Pacific?"

    According to sources I've found (below), the global CO2 levels are not exactly uniform, but they are very similar, with a >95% confidence interval of approximately plus/minus 5ppm, and an average of ~397ppm (Dec 2013). So if pre-industrial levels were below 300ppm, as has been reported, the significant change since of >100ppm can be measured essentially anywhere in the world.

    2013 global CO2 map (NASA): http://earthobservatory.nasa.gov/IOTD/view.php?id=82142
    2011 global CO2 map (Japan Meteorological Agency): http://ds.data.jma.go.jp/ghg/kanshi/info_kanshi_e.html
    Mean global CO2 (NOAA) : http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html

  7. "If a country is told to cut its CO2 levels by X%, how does anyone know if they have done this or not? How are a country's emissions measured (or calculated)"

    Again, I am an expert on mineral carbonation, but not necessarily on CO2 emissions, so I did some digging around on the web.

    The easiest way to measure a country's CO2 emissions is by summing the CO2 emitted from fossil fuels and cement production (which also generates CO2 from mineral calcination, the opposite of carbonation). This accounts for the vast majority of CO2 emissions from non-renewable sources (carbonaceous fuels and mineral carbonates) and thus can be easily accounted by simple mass balance: emissions = production + import - export.

    If a country is doing long-term CO2 storage or permanent CO2 sequestration, that can be added to the equation, and any such activities will probably be recorded accurately since carbon credits may have to be issued.

    CO2 emissions from renewable sources, e.g. cultured biomass, do not have to be accounted for, since they are renewable, so the CO2 will be taken up when the biomass is grown again. But land change use (e.g. forest clearing for cattle pasture, or the reverse) should be counted, since it has a longer term impact on the CO2 storage of that land.

    So there are some complications and uncertainties, but doesn't seem too hard to have a good estimate. It's not like the CO2 coming out of every tail pipe or flue stack has to be measured.

    1. Thanks RMS. I assumed it would be calculated in this way, but it is open to a little abuse and fiddling isn't it? And what about smelting, steel making etc, which use limestone flux, which must also generate a great deal of CO2?

    2. Ah, yes, how could I forget about steelmaking, I am working on capturing CO2 from steel plants. I think the easiest way to account for CO2 emissions from mineral calcination is to do the accounting like it's done for fossil fuels, at the producer rather than the consumer.

      Rafael Santos
      KU Leuven

  8. Barrie:

    Your questions were to climate scientists, so technically you are posting to the wrong group.

    Cira 1800 records include fixed sites and ship records. A lot of work has been put into converting this date to correct, for example, the effect of elevation of the thermometer above the land or sea. Things like oxygen isotope ratios in sea shells can tell the temperature of the sea in which the shell grew. I do not doubt that there has been a rise in temperature because of church and civic records from England. Since the year 1300 the Thames in London was frozen for ~44 days, the last of these was about 1813. That the temperature has risen since is obvious from this observation, but the cause is not. At the Hudson's Bay trading fort in Churchill, Manitoba, Canada, there is a record of when the river ice left that dates from1600 AD. It too shows a warming in the last 200 years, with the present breakup being weeks earlier than in 1800. It has not been a steady rise; in 1855 or thereabouts was a reversal for a few years that dropped on top of the ill-fated Franklin expedition.
    As others have said, the level of CO2 has risen. Things like air trapped in glass bottles and in ice support the recent climb in CO2, but not the effect. The models suggest that it is significant. I've heard that the path of the sun in the galaxy is the reason for our current warming, and of course the free enterprise chorus sings the "it's only a theory" song.

    Your third question is naieve, we know how much fuel is burned from sales records and how much CO2 is captured because the capture projects are well documented.

    While overall I support carbon capture as an ideal I think it is a joke. I pay taxes to lower the carbon in my car's exhaust in Vancouver while China opens a new coal fired power station every week. They argue that Britain did it for 200 years so why should they be penalized? Every ship in our harbour is running a diesel generator because we do not provide shore based hydroelectric electric energy. (That is changing, but not in place yet).

    To stay on the mining topic (?!) here in Canada companies are looking to switch engines and generators to liquefied natural gas so as to reduce carbon release. We have long since been scrubbing underground truck exhaust for safety reasons, so it's not new technology. Should we seriously tax carbon emissions to make solar and wind competitive? Are our politicians and snivel servants capable of deriving the right laws? I doubt it.


    K Armstrong P.Eng.

    1. Many thanks K. Regarding question 3, maybe it isn't that naïve. You say that we know how much fuel is burned, but do we? It is not the amount of coal mined which is important, but the amount of combustible coal which is produced after coal preparation. So we must rely on each country to produce accurate figures for this. Seems to me that this is a little open to manipulation. What do you think?

    2. Barry, I wrote a reply, but the "preview" feature swallowed it up and it's too late in the morning to do it all again.

      Two points I do want to make though:
      1. You wrote about your scepticism "...about the reliability of models describing this immensely complex system ".
      The system is complex, but NOT " immensely complex".

      2. In weather and climate forecasting some things are easy (temperatures), some are harder (precipitation), but the biggest error is in timings. So when an "IPCC report also casts some doubt on the models and their predictions of what will happen by the end of the century.", that should NOT be interpreted as "The IPCC don't believe the models".

      It may be the case that the IPCC could have said "We are seeing significant harm forecast - how quickly that arrives depends upon many factors, therefore we cannot be exact about specific times and specific impacts".

  9. Pity you did not leave your name, but you really believe that the earth's climate, and how it is influenced by the atmosphere and the oceans is not immensely complex?

    Whether the models are reliable or not, you have not answered my original questions, how do you reliably compare CO2 and temperatures now with the levels say a century ago?

  10. There are many ways to compare temperatures from a century ago:
    * Written records - logs, diaries, etc (see also http://www.oldweather.org)
    * Ice cores (see also http://science.howstuffworks.com/probing-the-history-of-climate-change-info3.htm )
    * Proxies (fossil numbers and types, tree rings, boreholes, etc
    (see also http://www.ncdc.noaa.gov/news/independent-evidence-confirms-global-warming-instrument-record )

    Some of these records provide definitive values and some show trends - both of which are useful in confirming or validating model forecasts. Some records are point specific, some are areal.

    In many cases, knowing one measure accurately allows for a reliable estimate of the other . If I live in Town X and you in Town Y and I take measurements every day, but (say) you only report erratically. After a while, I notice your Town Y is generally 4 degrees cooler than my Town X. If someone asks me your temperature, but I haven't had a measurement from you today, a reasonable estimate is to take 4 degrees off whatever my temperature is right now. It may not be correct (it might be cloudy with you but I may still be sunny), or it may not be accurate to 2 decimal places, but for all intents and purposes and in the absence of a recent measurement from you, it is more reliable than just guessing.

    Climate is complex, but it can broadly be described by temperature and humidity (i.e. precipitation) chiefly because we can reasonably accurately measure those two things. So if I said "Tropical Maritime" you will know I'm expecting warm and moist, "Polar Continental" would be cold and dry. Climate can also be described by flora and fauna, but meteorologists stick with temperature and humidity as descriptors.

    Re complexity: If a "Steppe" region received less rain, it would be classified as an "arid desert", but if it received more, it would be classified as a "tallgrass prairie". That's complex, but not immensely complex.

    Ocean and atmosphere are stratified into layers - the "Stratosphere" and "Troposphere" are distinct layers, with complex circulation patterns, but we know that most clouds occur in the Stratosphere and we know why: that is. complex but not immensely complex.

    1. Thanks anon, it all seems a bit wooly and unconvincing. Would be nice to know who I am talking to, but if you are a climate scientist it worries me a little that you consider the climate to not be immensely complicated

  11. As a regular reader of Dr Wills's (AKA my uncle Barry's) blog this particular article stood out to me as I was just about to teach this topic to my year 10 (age 14-15) students at Ormiston Ilkeston Enterprise Academy.

    After teaching them the theories of global warming and climate change I decided to present the students with the three questions posed by Barry. I asked them to answer the questions from their own knowledge and then research the topic and answer again.

    In doing this activity the students gained a greater understanding of the complexities in monitoring the climate and CO2 levels over time and how the media far too often reports snippits of Scientific research as the truth!

    They also appreciated being set work by a "real scientist" as apparently teachers don't count even if they have science degrees!

    Hopefully they have learnt that Science at research level is more complex than is reported in the media and that not all Scientist always agree on everything!

    FYI here are the initial responses to the questions from 2 Y10 students (Kami and Phoebe);

    1. You could measure the air temperature by measuring the carbon dioxide levels in ice cores from 100 years ago and then use the carbon dioxide levels to roughly calculate the air temperature at the time.

    2. No, we think this is a global average as we don’t believe that the carbon dioxide levels are the same all over the world. If we are correct then it isn’t reliable to compare the carbon dioxide levels of the whole world to the carbon dioxide levels found in ice cores in the Antarctic, as they could be different to other parts of the world that have more carbon emission.

    3. We think it would be better to calculate the amount of carbon dioxide released by a country because there would be less error in this method, as measuring it in the atmosphere wouldn’t be completely accurate for one country e.g France’s carbon emissions could get mixed up with the UK’s.

    Andrew Morrow
    Head of Science and Technology
    Ormiston Ilkeston Enterprise Academy

    1. Hi Andrew, many thanks for this. I think what you are doing with your students is exemplary. The most important message you can instil in young scientists is to question everything, particularly the dogma of the media. Nullus in Verba, the motto of the Royal Society, loosely means "take nobody's word for it", and it is a doctrine that I have always followed, as editor of a peer-reviewed journal, and which I hope you and your students will also do. As you know the backbone of scientific progress is peer-review, where scientific publication is rigorously questioned by fellow scientists, and conference presentation which leads to open debate. So keep feeding them provocative questions and encourage them to discuss, no matter how naive their views may appear to be.

      Maybe ask your students what they think of green approaches to energy, particularly with renewables, such as wind power and electric cars, then show them the other side of the story (postings of 11th February 2013 and 20 June 2011). All is not always what it seems and there is more than one side to every story. Keep up the good work, and make them question and think!

      Dr. Wills (AKA Uncle Bas).

  12. Research probing global warming ‘censored’ according to interesting article in The Times

  13. Somehow I missed seeing this Blog and very interesting discussions; for a lay man all this talk of "climate change" is confusing and makes him only frightened.He wants someone to write down,in simple language, three main reasons(causes) leading to what we call climate change. Then say whether any of them are avoidable-if not, what are the scientific solutions. If something is man made, I am sure there must be solutions or substitutes.
    I am putting this more as a lay person who keep on hearing on this.


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