Quiggin and Bolt: One last try for agreement on the numbers

I was at the Australian Conference of Economists earlier in the week, and had a chat with Roger Jones, who has occasionally commented here. I asked him about his estimates of the impact of emissions mitigation policies in Australia, and was able to confirm that our estimates, although reached in very different ways, are in quite close agreement. Roger is cited here and here, estimating that a 5 per cent reduction in Australia’s emissions would result in a reduction in equilibrium global temperature of 0.0034 degrees. In a blog comment, I made the estimate that a 25 per cent reduction, relative to business as usual (the official target of the carbon price policy and also of the Opposition’s ‘direct action’ alternative) would result in a reduction in equilibrium global temperature of 0.02 degrees.

Unfortunately, Andrew Bolt did not observe the reason for the difference, and suggested that we disagreed by a factor of five. For the second time, a comment I sent correcting the mistake was lost in moderation. I was inclined to give up at this point, but given that Bolt did admit an error in his own estimate that I had pointed out to John Humphreys[1], I thought it would be worth one last try.

Policy disagreements are inevitable, but it would be helpful if we could avoid unnecessary disputes over arithmetic. I’m always happy to check for, and if necessary correct, errors in my calculations. If Bolt and others could do likewise, we would have a better chance of making progress in public debate, or at least of avoiding regress.

Update I appear to have misinterpeted my conversation with Roger, though I need to check on a number of issues before making a final assessment. So, I’m going to withdraw my claim that Bolt and John Humphreys in error on this point, and discuss the estimates with Roger in more detail. I’ll report back when this is complete.

Further update Unsurprisingly, Andrew Bolt has enjoyed a bit of a gloat on the subject, and some of his fans have joined in. So, it’s worth reminding everyone that he was out by a factor of 100 in his own calculations, presenting the impact of one year’s emissions reductions as if it was the total effect over the next 100 years.

96 thoughts on “Quiggin and Bolt: One last try for agreement on the numbers

  1. I haven’t “corrected” my claims because I still can’t see how I was wrong. Roger Jones would have been talking about a 5% real reduction, which is the same as your 25% reduction from BAU… so you are looking at the same thing and coming up with different numbers.

  2. “Policy disagreements are inevitable, but it would be helpful if we could avoid unnecessary disputes over arithmetic. I’m always happy to check for, and if necessary correct, errors in my calculations.”

    For a few years I tried to get a handle on socio-political categories – I failed. But I feel comfortable with ‘social democracy’ as practised on JQ’s blog.

  3. @John Humphreys
    So, in this post JQ explained (again) the difference in assumed reduction starting points, and that he had ascertained what Roger Jones “would be talking about” by the radical technique of actually asking him. Have you also communicated with Jones about this? If not, may I ask by what reasoning you come to the conclusion that you are better informed about the gentlemen’s analysis than our host?

  4. @John Humphreys
    I’m going to repeat myself in bold I asked him about his estimates of the impact of emissions mitigation policies in Australia, and was able to confirm that our estimates, although reached in very different ways, are in quite close agreement.

    Obviously, in checking with Roger, my main concern was precisely what was meant by a 5 per cent reduction. I confirmed that Roger’s estimate was for a 5 per cent reduction relative to BAU, not the 25 per cent I was looking at (derived as a 5 per cent reduciton on 2000 levels by 2020, relative to the BAU estimate of a 20 per cent increase). Your assumptions about what he “would have been” talking about are false, as I’ve confimed in the most direct way possible, by going to the source.

    Just to hammer the point home, I’ve repeatedly invited you to do a simple reality check using tonnes of emissions avoided and a sensitivity number. I urge you, again, to do so.

  5. i’m going off topic.

    what’s going on in NSW?

    what is the state labor party doing?
    what do they think they are doing?
    who are these people?who do they represent?
    not the likes of me, that’s for sure.

    the current federal government is the most representative government i can remember.
    the idea that the people who voted for representatives other than the two main parties are somehow of no account and mistaken in their choice of MPs is a contemptible slur on the choices of those who voted.
    as the federal Labor team manages to govern as a true coalition by negotiation with elected representatives not of the Labor Party in the face of an incompetent,obstructive opposition why is NSW state labor trying to derail this?
    who are they?
    who are they working for?
    sqabbling for internicine advantage.
    secret reports to where was that again?
    coupled up apparatchics working against political rivals on the national stage,providing opportunity for federal opposition to sidestep their role in parliamentary debate by wasting question time in a frenzy dribbling nastiness.
    we see a shambling shadow that has gone past dysfunctional.
    there is no function to dys.
    unable to even pay it’s own way.
    maybe the best thing is to just pull the plug.
    call in it’s debts,dissolve the central branch and start again.
    disbarring any in the old branch.
    it would be no loss,any body who was doing the work for the principles worked out under the tree would have left ages ago.
    maybe they could put together a NSW Labor party that actually spoke for the people that do the work.
    instead of playing into the hands of those who think the richest need looking after.
    delete if you like JQ

  6. So, to summarize, the two scenarios involve a factor of ~ 5 difference in temperature reduction, but also a factor of ~ 5 difference in CO_2 reduction, leading to rough agreement on temperature sensitivity. Both men use BAU, which is the appropriate reference for measuring the effect of policy. Good, so that’s settled then.

  7. I’m very skeptical. The article you link to is clearly talking about a 5% real reduction (not against BAU) which is Australia’s policy. It would be very strange for Jones to study a 5% reduction against BAU since that is not on any agenda for anybody.

    I would very much like to see Jones directly enter the debate to clear things up.

  8. What on earth is “real” reduction if not against “Business as usual (BAU)”?

    Please explain the definition of each term, as you use it, to explain the difference. I can’t see what you mean otherwise.

  9. A “real reduction” means a reduction from current levels. So if we at the moment Australia emits 500 million tonnes, a real reduction of 5% by 2020 means that in that year we emit 475 (500-0.05*500) million tonnes.

    A reduction from Business As Usual means a reduction below what would have happened without the policy. So if, under business as usual estimates, Australia is likely to emit (say) 600 million tonnes in 2020, a reduction of 5% from BAU means that in that year we emit 570 (600-0.05*600) million tonnes. Note that in this case a “reduction from BAU” means a real INCREASE.

    Is it dishonest or tricky to use BAU? No, not if you’re clear about what you mean. We certainly want to get a real reduction (and not just a BAU one), but when we’re estimating the effect of a policy, we need to consider what the world would look like in its absence.

  10. Combet et al tell us we are aiming for 159 Mt emissions reduction relative to BAU. However 5% of year 2000 emissions of 553 Mt is a less impressive sounding 28 Mt. The big number fails the truthiness test.

    Other untruthy aspects of our concern for global carbon are plans to double coal exports and treble LNG exports. Should perchance carbon capture and storage not work by 2015 we are supposed to buy foreign offsets, a mid-range cost estimate being $25 bn. I suspect that if the ALP can hang on til 2015 instead we’ll slip the Indos a few dollars to save some forest with its cute orangutans. No doubt they’ll do a good job just like they are doing stopping the boats.

  11. This is a nonsense discussion.

    The aim is to eliminate 90% of our CO2 emissions. The 5% is simply the highest figure that every effort could get politicians to commit to in public.

    You’ve all completely lost the plot here. Let’s get back on message.

    Do you really need to have your own house demolished and your livelihood washed away by extreme weather before you focus on the true reality of the situation.

    The denialists have done a wonderful job of getting everyone’s expectations watered down to very little, and now even aguing about that last little bit, even though extreme weather is delivering an ever increasing toll of destruction. What’s in stall for us this summer? We’ve had the flooding rains, its time for some bush fires, with the consequent house fires, again. And doesn’t News Ltd just love all of this.

  12. Has the threat to our environment dissipated,….or gone away? Absolutely not.


    Totally the opposite. The feedback mechanisms thought to accelerate Global Warming are now kicking in, and this is evidenced very clearly in the Arctic. And everywhere else in a variety of ways. Just last week 1500mm, yes a metre and a half, fell over eight hours in one area.

    Apart from the ever increasing intensity and frequency of extreme weather events, the undeniable evidence that the atmosphere is changing is in the changing pattern of high and low pressure systems visible every night on the evening weather reports. At this time of year, winter, the high pressure systems should be tracking across central Australia in an orderly fashion. Not any more. They now like to reside below Australia summer and winter. Atmospheric air movements have altered very dramatically, far faster than atmospheric science can study and report on quantitatively. The end result of these changes still results in “weather”, it is just very different,…and we don’t know where it is leading to, other than an end game of apocalyptic heat for most of Australia.

    We ignore these changes at our peril. You pay attention to the denialists and Tony Abbott at peril to your intelligence.

  13. @BilB

    “Do you really need to have your own house demolished and your livelihood washed away by extreme weather before you focus on the true reality of the situation.” – BilB.

    Yes, they do BilB. On a global scale, a lot of that is going to have to happen before people take this threat seriously. A string of salutary disasters will happen to humanity before we collectively take any effective action. The disasters will get so bad that they will prune the population for us since we wouldn’t limit and stablise birth to death rates and growth ourselves.

    Arguing about 5% improvement when you really need 95% improvement to give even a 50% chance of saving the situation is beyond even black comedy. The ” endless growth capitalism until total collapse” brigade have won. Well, I hope they enjoy their “prize”.

    I think all people (including me I admit) are now living either in total ignorance or effective total denial. The horror, tragedy and inevitable nature of all this are too big to contemplate. I’m getting a 5.5 kw array of solars plus solar hot water on my roof. It’s all tokenistic and useless now. My family comprises four adults at home (with kids over 18) and has 3 cars, a ride-on mower, chainsaw, push mower, weed eater, 2 TVs, 4 computers etc etc. That’s got to be totally unsustainable. I’m as bad as the deniers.

    No human really wants to live like a “sustain-abilist”, a survivalist or a hunter-gatherer and no human will adopt such life modes voluntarily. It’s an extraordinarily tough life. All over 50s will die in short order (for example). Infant mortality will go back to something like 1 in 2. Etc. etc. The picture is so bleak that to paint it just promotes more denial.

  14. Bolt, Quiggin…whatever. All estimates are well below what could possibly be detected. These heated arguments about the undetectable remind me of nerds who argue about the details of the Star Trek universe.

  15. No point having this argument. Bolt wins regardless. He just creates the narrative that the carbon tax won’t have much effect, and even the experts can’t, apparently, seem to agree on the (very small) amount of benefit. To the average punter it is very compelling, particularly if he can keep an exchange going for a long time. The best way is to ignore him.

  16. Annabelle,

    There are a lot of arguments one could make of the intesimal.

    Why should we have a seat at the United Nations, we are just one of 200, what possible influence could we have?

    Why should I pay my $20,000 tax, it is such a small percentage… 0.000007%, as to be almost imeasurable? Try not paying it and see how upset Tony Abbbott gets about that.

    Conversely the governemnt should only tax people with lots of money because only they can make a difference. Try on that argument and see how hysterical Tony Abbott gets, and how quickly he forms a coalition with the Libertarians.

    Yes lets delve into pointless endlessly obfuscating arguments that ignore the reality that in large systems….every little bit counts.

  17. Though the pundits tell us Abbott is a shoo in for the next election there may soon be a repeat of the factor that helped elect Rudd … the presence of El Nino weather patterns with climate concerns by the public. Ironically it is a form of direct action that has helped the US achieve significant emissions cuts without explicit carbon pricing. That was an EPA emissions benchmark for power stations that coincided with their shale gas boom. However if as some predict cheap natural gas in the US will only last another decade then coal could make a comeback. Like Australia the US has joined the coal export bandwagon which gels with views that Chinese coal output has peaked.

    I think this time next year our emissions cuts will be modest compared to the large amounts (100s not 10s of Mt) advocated by climate scientists. Renewables will increase a smidgin and the economy will be subdued. If next summer is a scorcher voters will have ambivalent feelings about Abbott; they’ll want both decisive climate action and a return to strong economic growth. Perhaps they’ll end up with neither.

  18. John,

    sorry to come into this late and I have written a longer explanation that I hope will be soon posted at The Conversation. I calculated a 5% reduction from 2000 by 2020 and came up with a reduction in temperature in 2100 of 0.0038 degrees for a 3 degree climate sensitivity. I used the simple climate model MAGICC for this.
    A second calculation estimated a further 80% reduction by 2050. This produced a reduction of 0.02 degrees by 2100. Both estimates are proportional to Australia’s burden of global emissions. Let’s say that we wanted to reduce from the BAU estimate of 5.3 degrees in 2100 to 2 degrees for example and likened this to a 42 km marathon. Australia’s 2020 target is equivalent to 48 metres and the 2050 target is about 250 metres. Australia would get the direct benefit from the 250 metres we ran and the other 41 km 750 m that all the other nations ran, if successful.
    The Andrew Bolts of this world want to deny the simple truth of these sorts of numbers.

  19. Oh, and to address John Humphrey’s comment at #9, the benefit is not very sensitive to the underlying emissions – it tends to be net. This is not strictly true but the differences are less sensitive than differences in climate sensitivity and emission rates. Where it does matter is for overshoot rates where emissions get to less than the natural take-up – about 55% fewer emissions than the world is putting out now. If the world is appreciably warmer, this number will need to be greater because the natural sinks will be less efficient than they are now.

  20. I am going to post this (my) comment from Roger Jones excellent site as i believe that it is rlevent to this thread also. The comment is to a Mike who claims that Bolt has “won again” and that Jones should give up and shut up.

    “Mike @ 11.29

    Bolt only “wins” arguments through censorship/selective publication. If you do not understand that then you are a toadie and not worth talking to.

    The real fact(s) that Bolt a). does not understand, I would venture, and b) will never talk about is the true cost of the .0038 C.

    Australia’s global temperature .0038 policy impact share must be assessed as its part of the GLOBAL ECONOMY.

    It is a global temperature which is relative to the global economy. Do you understand the distinction?

    The Global Economy which will be reduced to near zero by a 5 degree C rise in temperatures is what is at stake here.

    In todays terms this is $69 trillion. Australia’s current .0038 policy impact share on that economic activity is $236 billion. In fact it is the inverse of that. ie if all Austalia achieves is a .0038 degC improvement then its share of saving the the global economy amounts to just $236 billion in today’s terms.

    However, if Australia achieves a .02 degree C reduction in temperature rise then its improvement share to the global economy will amount to $1.35 trillion. In other words we will have saved the Australian economy at a short term marginal cost.

    Do you understand this?

    Andrew Bolt is a technologic Dunce. If you swallow his swill then you will become a Double Dunce. More significantly, your children will have no future and almost certainly die young.

    I have just been outside after being inside all morning. It is summer here in Emu Plains NSW, in the middle of winter. That is both weather and changed climate.”

  21. Bolt is a paid entertainer, it’s his job to be controversial. I suspect he may even enjoy it.
    I’m certain he’s intelligent enough, given time and study, to understand the strength of the evidence but having nailed his colours to the mast, he may have a problem backing down.

    Even so, I admire John Quiggin, Tim Lambert and others who take the time to try and engage him.

    The facts speak for themselves, more clearly with every year that passes, and those who choose to ignore them will pay the price in due course.

    Unfortunately, for those of us at or approaching middle age, that time is far enough away that we will probably all be being spoon fed in a nursing home or feeding the worms.

    The white hats, having been vindicated, do not get to ride triumphantly off into the sunset…

  22. Happy Heyoka,

    At middle age your later years may well be spent in the full onset of climate change. In fact your life will almost cerainly be cut short if climate change and resource depletion proceed unrestrained.

    Your most certain climate change related fates include

    heat exhaustion/stroke, drowning, crushing, hyper thermia, failure of services/medicical resources, incineration (while alive), lightning strike, loneliness induced suicide, starvation.

    On current Coalition Climate Mitigation policies one of those fates will be yours if your body does not fail due to desease or medical condition.

    There is no room for age complacency here. Remember it is not just Climate Change Risk to be concerned about, resource depletion is guaranteed to limit our ability to do the changes that are required to limit our CO2 emissions. The steady upward march of the price of oil will within the next 8 years cause even stable economies to fail.

    That is absolutely guraranteed.

  23. The idea that only the unborn will suffer significant consequences from climate change is fanciful. Change is accelerating,and the most consistent aspect of forecasts is that they have underestimated changes, and that with every new report they have been revised upward.
    Unless you have scheduled your departure for this year or next, worry!

  24. @Megan
    To solve the problem of whether it is ‘our’ coal just carbon tax finished goods from China and India on the presumption that they are coal intensive. For administrative simplicity make the carbon tariff 10% or 20%. If they say the embodied energy was clean let them hire lawyers to make the case.

    Australia, the EU, Nordic countries and others could form a low carbon customs union to enforce this. When China and India have CO2 penalties remotely resembling $23/t we can drop the tariff. As a bonus we may not have to subsidise our metals industries so much, for example 94.5% carbon tax exemption and $300m cash for steel.

  25. @Freelander, @BillB while I don’t in general disagree, you miss my point(s)

    I’ve spent a good deal of my professional life doing things like optimising temperature control in a furnace that takes months to heat or cool and, conversely, tracking and processing events that take nanoseconds or microseconds.
    Human perception just doesn’t cope with extremely time spans (eg: heating or cooling something with the thermal mass of an ocean).

    Second, I’ve spent a lot of time dealing with complex interactions between complex systems.
    Human perception also doesn’t cope well with that kind of thing. Climate is complex – I’ve messed around with trying to correlate and process some of the data sets for personal interest. I highly recommend it if you wish to feel humbled.

    While I totally agree that BAU will result in a catastrophe of proportions unseen by modern human society, it’s not going to happen like a car crash all in one instant, and attribution of the adverse biosphere events will remain peskily difficult – always leaving room for “it was the sun” or “it’s a natural cycle”.

    I don’t disagree with the need to get working on mitigation efforts, personally and professionally I’m doing all I can with what I have.

    My interest outside of that, in the “political sphere”, is in trying to understand how otherwise intelligent people (eg: Bolt) either don’t get it or decide to manipulate those who “don’t get it”.

    Exploiting the limited attention of people who’s main concern is next months mortgage payment is neither a new or a novel technique but it’s effective… a persuasive argument by someone like Bolt has these folks thinking “well, that’s all right then” and off to the sports pages.

    Mitigation Efforts suffer a lot of turbulence and drag from this.

  26. Good on you, HH.

    The comment is not directed at you personally, but at the attitude that we, the control generation, will personally escape the consequences of our actions,…so why should we care.

    The comment is also directed at those who imagine that they can delay action until the effects such as sea level rise are about to engulf their home at which point a simple change of mind will put the situation back to “normal” and the problem will just go away after some tidying up and the planting of some new shrubs.

    Tell me, though HH, do you appreciate the rapidly approaching risk to economic stability due to resource depletion? And further the consequent risk to climate change adaptation?

  27. @Happy Heyoka

    “My interest outside of that, in the “political sphere”, is in trying to understand how otherwise intelligent people (eg: Bolt) either don’t get it or decide to manipulate those who “don’t get it”.

    Exploiting the limited attention of people who’s main concern is next months mortgage payment is neither a new or a novel technique but it’s effective… a persuasive argument by someone like Bolt has these folks thinking “well, that’s all right then” and off to the sports pages. …”

    No, you actually explain it perfectly.

    That’s why I’m so pedantically ANTI Murdoch at every turn (won’t tollerate a single click on News Ltd or anything that further enables the very phenomenon you identify there).

  28. I’m always amused by the conceit of the weekend scientists and their adventures in modeless data manipulation, where the professionals seem to require just that bit more equipment and training.

    Turning to Bolt as a source of peer review … say no more …

  29. Bolt probably has no doubt that anthropogenic climate change is real, but will nevertheless continue his posturing while laughing all the way to the bank.

  30. From the comments above from Roger Jones it is now clear that my interpretation was correct and JQ was wrong. Jones has clearly said “I calculated a 5% reduction from 2000”, which is a real reduction, not a reduction from BAU.

    JQ earlier: “I’m always happy to check for, and if necessary correct, errors in my calculations.”

    We will see…

    Given the repeated public claims that I was refusing to correct “erroneous claims”, a small apology wouldn’t go astray either. The peanut gallery who mindlessly clapped along to the JQ tune might also let this be an opportunity to pause and re-think.

  31. @Roger: Sorry to press you on this, but as you can see the issue remains live. I understood you as saying that you compared a 5 per cent reduction by 2020 to an alternative of no change. Can you spell out the trajectories you had in mind?

  32. @John Quiggin, John Humphreys

    Have any of you (AB, RJ, JH, JQ) published something like a spreadsheet? You know, starting assumptions for emissions, temperature rise per tonne, that sort of thing? I’m guessing all of you used one and didn’t just scribble it out long hand.

    I followed some of your links and the Herald Sun stuff in particular is now pay-walled (the actual print copy here is probably well and truly used by the puppy by now).

    It might be informative to approach it that way rather than bat “who-did-what-how” backwards and forwards…

    I have no idea how well accepted Damon Matthews methodology is… given it’s been a couple or three years since the Nature article in question there should be some discussion of that by now.

  33. John Q,

    sorry – thought I’d been quite clear when we spoke but may not have distinguished the Australian baseline from the global baseline sufficiently. I did say that I’d taken the -5% from 2000 to 2020, then run it through to 2100. You then said (I think) that was equivalent to your assumption from the level of treasury growth – I agreed. The temperature run that I then did was that reduction from a global BAU – namely the Garnaut A1FI (that I originally ran for the Garnaut Review – I set up the scenarios they used). So it’s Australia acting to 2020 as per the policy of the Laboral, sorry, Libor parties, then maintaining that when the rest of the world does not.

    The -5% in 2020, then -80% in 2050 was the 0.02 degree in 2100 reduction. However, that was reduced from a different scenario – this one is A1B on steroids, which reduces global emissions from about 2040.

    A bit more work needs to be done to make all of this publishable – running them under a wider set of global assumptions, basically.

    Have just check the spread sheets to confirm. Will not be releasing them until I have the results submitted and reviewed. Not sure when that will be. I could publish some summary graphs but there is a lot going on and would have to do a bit of work on presentation.

  34. And in the latest bizarre weather news, while Southern Japan is getting the Toowoomba treatment, there is an outbreak of three tornadoes in Poland, the second such series in recent times (the first being in 2008).

    Of course it is just a fluctuation.

    And, yes, I watch the foreign news casts on SBS as the ABC thinks that reporting Tony Abbott declaring that he will “get rid of that toxic tax” for the six thousandth time is actually news.

  35. ok, so I’m a dummy: the more comments I read regarding the link I posted, the more I realised they were talking about a different Nature letter by H. Damon Matthews (guy is a rockstar, has been published in Nature proper as well as Nature Geo.)

    The correct article is The proportionality of global warming to cumulative carbon emissions

    I hope nobody misspent their hard earned because the spiders in my wallet prevented me from stumping up…

  36. So you were wrong. And yet you claim to be an expert etc etc ad nauseum add the usual crap and call me a denier and now are getting a taxpayer funded sinecure to perpetuate this shameless mess of lies and exaggerations for base political purposes.

    I guess the cash makes it all ok. Your conscience must be a wonderfully malleable thing.

    You and your ilk disgust me. History will laugh at you. That is my consolation, your legacy will be trashed along with many others of the sycophants and zealots on the gravy train.

    Enjoy it while you can. You have just over 12 months before the piper will be paid.

  37. Mark,…your’re upset! Didn’t get your milk and cookies and couldn’t sleep?

    The best thing is to think positive thoughts, and you will drop off to sleep in no time at all!

  38. @Roger Jones

    If the world is appreciably warmer, this number will need to be greater because the natural sinks will be less efficient than they are now.

    Natural sinks? Global vegetation would be one of those sinks, and the last I looked, very little vegetation grows at the cold polar ends of the world. They seem to like warm and wet a la the tropics.

    Leaving the sarc aside, we need to admit that our knowledge of the carbon cycle and the forcings and feedbacks that influence our climate is lacking (as the IPCC so acknowledges in the Summary for Policy Makers, levels of scientific understanding).

    In which case, making far reaching important economic decisions based on low levels of understanding which may or may not reduce global temperatures by a poofteenth of a degree seem to me to be bad policy.

  39. The deniers seem to get sillier and sillier as the evidence for AGW gets stronger and stronger. One can feel their pain. That pain shared with the terrible twos toddler throwing a temper tantrum.

    It is funny though.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s