Chief Scientist’s arguments for alarmism don’t wash

Models fail

Models fail

Professor Ian Chubb, writing in The Australian, responds to Maurice Newman’s recent articles on climate change. But in my view, he fails to make a case for urgent action. The following two sentences encapsulate Chubb’s approach:

I start in a different place and ask a simple question. We have so far pumped two trillion tonnes of a greenhouse gas, CO2, into our atmosphere since the Industrial Revolution, at a rate faster than ever before. Why would we presume that it would have no effect?

If the answer were simple, we would know it. So we have to use the evidence we have to assess the impact now; and we have to use the data to build models to estimate what the impact might be in the future.

Firstly, the reference to “two trillion tonnes” is classic misdirection, of which any magician would be proud, since to the lay reader, it sounds like a truly gargantuan amount – and in absolute terms, it is. However, it isn’t until one realises the entire atmosphere has a mass of five quadrillion tonnes (2,500 times Chubb’s figure), that the sleight of hand is exposed.

But rather embarrassingly for a Chief Scientist, even the figure of two trillion tonnes he cites is wrong. The mass of CO2 in the atmosphere today is approximately 3.16 trillion tonnes (591ppm by mass, 400 ppm by volume). Prior to the Industrial Revolution, CO2 accounted for approximately 290ppm by volume in the atmosphere (equivalent to 428ppm by mass), so pre-industrial mass of CO2 would have been 2.3 trillion tonnes – the difference being about 0.9 trillion tonnes. “We” have “pumped” less than half the amount of CO2 into the atmosphere that Chubb claims.

Furthermore, nobody “presumes that it would have no effect”. We acknowledge that CO2 is a greenhouse gas which will cause some degree of warming. Chubb’s rhetorical question sets up a straw man. The question is not if, but how much?

The models that have been built to estimate the impact of this warming in the future have been shown to be significantly overestimating the contribution of CO2. The IPCC’s blinkered approach has ensured that the majority of natural climate drivers (including the Sun) have been ignored, discounted or dismissed. As a result, the sensitivity of CO2 had to be cranked up (by invoking large positive water vapour feedbacks) to enable to models to match the past. Because CO2 continued to increase, the models predicted continually increasing temperature, but real-world measurements are diverging from model predictions and there is no ‘consensus’ on the reason why (see The Cause has seven excuses for The Pause).

None of this is entirely surprising, given the UN’s scapegoating of CO2 as the culprit at least thirty-odd years ago, and IPCC’s remit to investigate ‘human-caused’ warming.

Similar “why would we presume” arguments are put forward in relation to ocean ‘acidification’ (which he correctly labels as ‘less alkaline’) and ocean heat content. The former is not disputed (although the magnitude of its effects might be), but the latter has been dredged up as one of the convenient excuses for the models failing to match observations (see Rapid increase in ocean heat?).

Chubb quotes a Nature article on models:

“Some have argued, in part on the basis of current temperature trends, that climate models tend to overestimate warming … (but) the evidence cuts both ways.” Some seem always to presume the errors only occur in the direction favourable to their argument. Notwithstanding the range, current models point out a direction, and the direction is up.

Looking at the plot above, can you see the evidence ‘cutting both ways’? How many models have underestimated warming? Since 2005, none. And errors at the IPCC are always in the ‘it’s worse than we thought’ direction – despite the fact that statistically, one would expect a fairly even balance both better and worse.

Chubb concludes:

I am sure Maurice Newman and I would agree that much of what should be a debate has turned into “low-grade” and often personalised argument. What it should be is a healthy and constructive discussion based on all the empirical evidence, not bits of it, and with an eye to the implications for our health, wellbeing and prosperity in the longer term.

With ‘denier’ smear-sites like Skeptical Science, RealClimate and Think Progress still around, I won’t be holding my breath.


Full article here:

Surely CO2 is a climate culprit

AFTER his three recent articles on climate change, most recently on Wednesday, in The Australian, it is clear that Maurice Newman and I can agree on a number of things.

We can now agree, for example, that climate change is real, not a myth or a delusion. We can agree that he is not a climate scientist; and we would agree that I am not one either. We would, I think, agree that a “climate” is the result of complex interactions of multiple variables, many of them natural, but I would say not all.

We diverge when it comes to the impact of greenhouse gases. While we agree that carbon dioxide is a greenhouse gas, Newman wrote of “the myth of anthropological climate change” (The Australian Financial Review, September 13, 2013) and suggested that it is one in a list of popular delusions.

Others will doubtless address some of the details he has raised. I start in a different place and ask a simple question. We have so far pumped two trillion tonnes of a greenhouse gas, CO2, into our atmosphere since the Industrial Revolution, at a rate faster than ever before. Why would we presume that it would have no effect?

If the answer were simple, we would know it. So we have to use the evidence we have to assess the impact now; and we have to use the data to build models to estimate what the impact might be in the future.

Right now we know that as CO2 levels in the atmosphere increase, so too does the amount of CO2 absorbed by the ocean, with the effect of making the water less alkaline (or more acid). Why would we presume that would have no effect on marine life? We also know that the heat content of the oceans has increased consistently although the rise in atmospheric temperature recently is flatter. Why would we presume no effect on the currents, winds and evaporation, and a subsequent impact on climate? We know the planet is warmer than pre-industrial times. While some might dismiss this as just a few tenths (0.9C) of a degree, I wonder if they’d be as sanguine if their core body temperature increased by the same few tenths of a degree.

There will be regional variations. There are differences even within Australia: temperatures in some regions have increased by 2C over 50 years while others have experienced little or no change. Our average change is 0.7C.

We know that greenhouse gases in the atmosphere are important. If there were none, it has been estimated that the global temperature would be around -18C rather than the average near 15C we currently enjoy.

We also know that the relationship between CO2 and temperature is not linear. Uncertainty about the sensitivity of the climate to changing CO2 means models yield different projections. As an editorial in this week’s Nature says: “Some have argued, in part on the basis of current temperature trends, that climate models tend to overestimate warming … (but) the evidence cuts both ways.” Some seem always to presume the errors only occur in the direction favourable to their argument. Notwithstanding the range, current models point out a direction, and the direction is up.

So we know that climate is a complex, complicated matter and that there are multiple variables. Does that mean we don’t use all the information that we have to estimate what might be ahead? Does it mean that we do nothing about one variable over which we have some control – the emission of greenhouse gases? Does it mean that because there are uncertainties, we do nothing?

I am sure Maurice Newman and I would agree that much of what should be a debate has turned into “low-grade” and often personalised argument. What it should be is a healthy and constructive discussion based on all the empirical evidence, not bits of it, and with an eye to the implications for our health, wellbeing and prosperity in the longer term.

Professor Ian Chubb is Australia’s Chief Scientist. (source)

Comments

  1. Lew Skannen says:

    “Notwithstanding the range, current models point out a direction, and the direction is up.”

    How lame. The direction has been ‘up’ since about 1650 and there has been no significant change in the rate since the industrial revolution.
    The important point about the graph is that it shows that the models are WRONG. That is the fact that he is desperately trying to gloss over.

    Australia’s Chief Scientist? What a sad state of affairs! I am glad that my physics lecturers at uni have passed away because they were great scientists and this state of affairs would break their hearts.

  2. Chubb obfuscates the argument in his opening statement. What could a scientist possibly mean when he says “We can now agree, for example, that climate change is real … ” Is Chubb, in all seriousness, conceding that climate changes? What appallingly misleading language from a Chief Scientist. Instead of perpetuating this dishonest language, indeed using it to his own advantage, he should exercise his leadership by restoring some modicum of honesty to the narrative of the debate. This debate will never come to a conclusion using dishonest language. Some leadership please Chubb. You are the Chief Scientist. You can set the terms of reference and the rules. What are we debating? Global warming? Climate change? Extreme weather events? Please restore some meaning to the words we can debate with.

  3. We have to cut them some slack, after all, all that they have left is lies and twisting the truth so we have to feel sorry for these liars and just let them rant as their suffering will be over soon. N

  4. An absolutely hilarious letter in “The Australian” today. Here is a cut and paste for those who fear the paywall (is this a no-no or is it OK). Clamp jaw shut – here goes:

    “IAN Chubb has nailed it, distilling into one column the reality of predictive climate models (“Surely CO2 is a climate culprit”, 17/1).

    Another point that sceptics evade is an understanding of the law of conservation of mass. The likes of Chubb and Brian Schmidt should not take as a given that the population understands this principle of science.

    If we have pumped 2 trillion tonnes of carbon into the air, where has it gone? Nowhere.

    Every atom of carbon that we have mined from the ground and put into the atmosphere is still hanging there.

    The law of conservation of matter is a part of the Year 9 curriculum. As a science teacher, I make sure to teach it well in such an important context.

    Instead of laying bets, perhaps Maurice Newman should be tested for his understanding of this concept before entering the debate.

    Dr Peter Wilson, Fentonbury, Tas”

    Perhaps we could rename it “Wilson’s law of the inmmutability of man’s nefarious influence”.

    But seriously folx- perhaps it’s OK on Tasmania, but I wouldn’t want this character teaching my (figurative) kids science. Even the warmists wouldn’t be too keen on him denying the oceans are acidifying. Perhaps Dr wilson got his doctorate in one of those places where the world is 6000 years old- do they have global warming in those?

    What about it Chubby. You’re the Chief Scientist- are you going to let science teachers like this inform the debate on your side?

    • “If we have pumped 2 trillion tonnes of carbon into the air, where has it gone? Nowhere.

      Every atom of carbon that we have mined from the ground and put into the atmosphere is still hanging there.

      The law of conservation of matter is a part of the Year 9 curriculum. As a science teacher, I make sure to teach it well in such an important context.”

      As a Professor I can assure you that is false. A CO2 molecule in the air has a half-life of about 10 years. There are about 3700 giga (billion) tonnes of CO2 in the atmosphere and 50 times as much in the oceans. Very little is from fossil fuels.

    • Yeah, I saw that letter as well. If he really is a science teacher her should be sacked. The oceans absorb a LOT of CO2 and I’m pretty sure that plant life sucks in a lot of it as well. This guy is either an idiot looking for a village to inhabit or an ideologue deliberately seeking to deceive. And as for Chubb’s original statements. so what ? Who cares howmuch CO2 we “pump” into the atmosphere ? Isn’t it’s effect on warming logarithmic ie the more that gets added to the atmosphere the less effect it has ?

      • I’m on your side Simon but your answer needs clarification because it obscures the difference between ‘average’ and ‘marginal’ (just like in economics). Every additional (marginal) tonne of added CO2 has less and less effect but the enhanced heating effect of total CO2 would raise temperature but by such a minute amount that you wouldn’t even be able to measure its affect, not even after 1000 years; and all that if one believes that CO2 is the only factor in changing temperature (which obviously is not the case). From my own area of knowledge (geology) it would seem that CO2 levels in Cambrian times (say 500 million years (Ma) before present (BP) in the atmosphere were around 5000 ppm. The Cambrian is noted, inter alia, for a huge explosion of multicellular life on Earth — numerous species of sea creatures happily multiplying and evolving. No problems then.

  5. Might be time for Mr Abbott to send Chubb packing like he did with that goose Flannery. Appoint a real scientist like Plimer to the position.

  6. Old Ranga says:

    Simon says: “Chubb’s rhetorical question sets up a straw man.”

    Couldn’t have put it better. Data beats rhetoric every time.

  7. Ross Stacey says:

    Has Chubbs missing CO2 gone into the ocean?

    • Yes, and from there into the mineral calcite (CaCO3) in various forms like in corals and shells, which then form carbonate rocks like limestone and dolomite, but all that takes a very long time.

  8. “Does it mean that because there are uncertainties, we do nothing?”

    The odds of being killed by a comet or asteroid impact are far, far higher than being killed in an air crash (source: Spacewatch). Globally, humankind spends billions and maybe even trillions every year on air safety. We spend modest amounts on detecting near-earth-orbiting objects but do nothing.

    It’s impossible to set odds on being abducted and eaten by aliens, although according to several highly respected celebrities in the music and entertainment worlds, there’s no doubt it is happening. Even so I would like to suggest that humankind does nothing about this problem.

    Full marks to Ian Chubb for not using the D-word. I think I could get to like this man. Not so many marks to Simon for using the A-word.

    • Please propose an alternative to the A word, as I am yet to find one (and it hardly has the stigma of the D word). But I take your point.

    • Lew Skannen says:

      I don’t see anything wrong or derogatory about the word ‘alarmist’. They are not just telling us that the planet is warming they are telling us that it is warming dangerously and that we have to do something about it. To me that is an alarm.
      I happen to think that they are dishonest, misguided and self serving but that is another matter.

  9. Ivor Ward says:

    “”What it should be is a healthy and constructive discussion based on all the empirical evidence, not bits of it, and with an eye to the implications for our health, wellbeing and prosperity in the longer term.””

    Another rather stupid statement from Chubb. It is not possible to argue about the entirety of Climate science in one go. Each protagonist would need a document as long as the IPCC AR5 to lay out his case. We argue science in detail, not in totality. “Is the temperature warmer or not.” “Is sea ice growing or shrinking?” etc etc. Each topic is argued in detail and eventually an overall position is reached. One tiny detail falsifies a hypothesis. Furthermore I do not think the word “presume” features in many scientific text books. We do not presume, we make judgements based on empirical evidence. Models are not evidence.

  10. Graham D Chubb says:

    Professor Ian Chubb (no relation) gave up any pretense of being a scientist when he abandoned the principles of science (see Karl Popper) to take up political advocacy.

  11. How ironic: “we should not presume”, yet that’s exactly what alarmists do. Reeks of Suzuki’s “humility” statement, wherein he proceeds to have none.

  12. Streetcred says:

    Chubby and his mates should get together with Dr Judith Curry for a lesson in atmospheric physics:

    # For the past 16 years, there has been no significant increase in surface temperature. There is a growing discrepancy between observations and climate model projections. Observations since 2011 have fallen below the 90% envelope of climate model projections.

    # The IPCC does not have a convincing or confident explanation for this hiatus in warming.

    # There is growing evidence of decreased climate sensitivity to atmospheric carbon dioxide concentrations.

    # Based on expert judgment in light of this evidence, the IPCC 5th assessment report lowered its surface temperature projection relative to the model projections for the period 2016-2036.

    http://judithcurry.com/2014/01/16/senate-epw-hearing-on-the-presidents-climate-action-plan/

  13. Michael blazewicz says:

    Ross Stacey asked if the discrepancy of.9 trillion tonnes in the atmosphere was absorbed into the ocean…please respond..

    • There is ambiguity in Chubb’s statement. If it were the total emissions since pre-industrial times, then his figure may be correct, as there are multiple pathways via which the excess would be sequestered, including ocean absorption. However, in terms of what has been actually resident in the atmosphere, compared to pre-industrial times, then the figure is wrong.

  14. Michael blazewicz says:

    The other issue is that you refer to Chubbs claim that 2trillion tonnes is a classic misdirection as a it only represents I/2500 of the total atmosphere. Humans need magnesium for our bodies to function correctly which represents 1/ 2800 (based on 25 gm. In a 70 kg body)…this balance is delicate…not a misdirection I would suggest.

    • I think that none of this is relevant. There are many sources and sinks in the Carbon Cycle in partial equilibrium and all in different time frames. In terms of planet evolution we now live in a time of CO2 deprivation. As I said in a previous response atmospheric CO2 levels in the Cambrian (say 500 Ma BP) were around 5000 ppm and that has been declining on a broad scale ever since. Perhaps Professor Fritz (response near top) can enlighten as further.

  15. Professor Ian Chubb, should look at the impact of human activity Co2 emissions from the following perspective:

    (i) Scientists tell us that about 95% of the total atmospheric greenhouse heat effect is due to water in the atmosphere.

    (ii) This means that about 5% of the total atmospheric greenhouse heat effect is attributed to greenhouse trace gases.

    (iii) Co2 represents about 72% of the greenhouse trace gases. This means about 3.6% (72% x 5%) of the total atmospheric greenhouse heat effect can be attributed to Co2.

    (iv) But the 2007 IPCC AR4 asserts that only 3% of the Co2 entering the atmosphere each year is from human activity. The overwhelming 97% of Co2 entering the atmosphere each year is from natural sources.

    (v) Consequently, the 3% Co2 from human activity can only be responsible for about 0.11 of 1% (3% x 3.6%) of the total atmospheric greenhouse heat effect.

    This begs the question – Is the human contribution to the atmospheric greenhouse heat effect, i.e. 0.11 of 1% of the total atmospheric greenhouse heat effect, of any consequence?

    The scientific reality is that the human contribution to global warming is statistically insignificant and scientifically irrelevant. Eliminating all human activity on Earth would have no discernible impact on the total atmospheric greenhouse heat effect.

    What say you, Professor Chubb?

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