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

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

July 13th, 2012

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.

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  1. Freelander
    July 22nd, 2012 at 03:19 | #1

    Don’t worry about Baa Humbug, no surprise deniers pulled the wool over his eyes.

  2. Tony
    July 22nd, 2012 at 05:42 | #2

    Oh dear, some very serious egg on face here for both the author and a large number of bloggers who piled in to criticise Andrew Bolt in particular. To all those who are so ready to attack the intelligence and motives of anyone who disagrees with their ‘climate’ beliefs I suggest it is time to consider the way in which you approach the debate.

    Fact is Bolt is right. He was right all along and there is much the ‘warmists’ need to learn from those like Bolt who actually analyse and understand the underlying issues rather than mindlessly repeating the strident trumpet calls of the fear mongers.

    Sadly I expect that even public humiliation like this is not enough to bring about a change in attitude though. Fear does that to people – makes them impervious to sense and sensibility. You only have to read some of the comments here about 5 degree rises in temperature and fanciful extreme weather events to realise which side of the debate is being driven by mindless fear.

  3. Graham
    July 22nd, 2012 at 07:55 | #3

    “I appear to have misinterpeted (sic)…”

    Not only a prize goose, but a grammatical dumb ass as well.

  4. Mark
    July 22nd, 2012 at 08:37 | #4

    @BilB

    Marvellous retort BilB. Full of consensus science and the matter to hand.

    Quiggan was wrong. Painfully wrong. So wrong in fact he should hang his head in shame but of course that does not get one a publicly funded job these days does it?

    Perhaps you should look at what is occurring and not what is modelled or lied about to further the appropriation of public funds.

    It isn’t hard son. you will pick up the whole concept of thinking for yourself in no time.

  5. July 22nd, 2012 at 09:17 | #5

    Whether it’s 0.0038 or 0.02 degrees, where are you going to find a thermometer to measure such a small temperature difference? They don’t exist. Thermometers do not go beyond one decimal place.
    So you want to enact a government policy that will make such a small temperature difference that it can’t even be measured?

  6. Baa Humbug
    July 22nd, 2012 at 09:18 | #6

    @Freelander

    Don’t worry about Baa Humbug, no surprise deniers pulled the wool over his eyes.

    And that was the sum of your contribution. Well done.

  7. BilB
    July 22nd, 2012 at 09:21 | #7

    No Freelander,

    BaaHumbug represents the entire Coalition and all of those people who do not have the time or inclination to follow the science of Climate Change so accept their information predigested, acidified and regurgitated from the likes of Bolt. He must be addressed, particularly now.

    BaaHumbug, I will assume, is suggesting that the tiny Carbon Pricing regime that Australia has enterred into is a “far reaching economic decision”, and he holds that view I imagine because Andrew Bolt has told him to think that. The likes of Bolt and Abbott who who can only deal with one “fact” at a time are unable to comprehend that the Carbon Price is the first and only mechanism put in place to protect the Australian economy not only from Climate Change, but Peak Oil as well.

    BaaHumbug is so enraged by the red herring being dangled in his face by Bolt that he does not see that he is being gouged on his electricity pricing by the power companies who are quietly escalating the cost of energy beyond any precedent in Australia’s history. The Carbon Price red herring at 2 cents per unit ……the power companies 10 cents per unit. And if BaaHumbug and his like kind idiots are stupid enough to vote in Abbott, the 2 cents per unit will not come off, there will be another 6 cents added. If expect that it will take BaaHumbug ten years to do the maths on that little con. And the most tragic aspect to this is that the power generators will then be earning heaps more cash to carry on as usual exacerbating the CO2 problem immensely.

    And that is very much part of the reason why Quiggin has no need to retract. The calculation is incomplete. The BAU scenario is far worse than predicted in so many ways. CO2 emissions in the hands of the religious right will increase 50%, and the Earth has many more surprises in store for CO2 emissions of its own inresponse to the escallation. This is what Roger Jones was referring to.

    And if all of that was not bad enough, there is Peak Oil. Petrol prices are vascillating by 30 cents a litre at present. This gives some indication of the instability of the oil supply, as well as the greed of the oil industry. This means a cost variation of $450 dollars a year for me even for the tiny amount of driving that I do. This is the tip of the energy dilemma heading our way. Economies are already being destabilised by their energy costs at the Peak while oil demand is still being met. In just a few years time when oil delivery dips below the global demand economies will start to fail significantly.

    Electrification of industry and transport is the only viable solution for a table economic future for most countries in the world. But standing in the way of that is the genius of …..Tony Abbott. The mouth. And the other idiot….Andrew Bolt. The Pen.

    But let’s not forget BaaHumbug. The thinker.

  8. Baa Humbug
    July 22nd, 2012 at 09:26 | #8

    @BilB

    And what far reaching economic decision would that be BaaHumbug?

    CO2 is a byproduct of modern activity. taxing and or trading CO2 as a commodity has far reaching effects. Artificially increasing the cost of energy has far reaching effects.
    It hasn’t been a difficult political outcome for no reason.

  9. Baa Humbug
    July 22nd, 2012 at 09:28 | #9

    @BilB
    Grow up

  10. Hermit
    July 22nd, 2012 at 09:39 | #10

    I have mixed views about Prime Minister Abbott’s direct action plan since by accident or design it could generate bigger emissions cuts than carbon tax. The fact the US has made significant cuts without an explicit carbon price has been put down to recession, shale gas (fracking) and EPA smoke rules.
    http://grist.org/climate-policy/u-s-leads-the-world-in-cutting-co2-emissions-so-why-arent-we-talking-about-it/

    I expect around election time when CT has disappointed we’ll hear all the horror stories of new coal plants being built. We won’t hear how CT could be made tougher so I’m ambivalent about a change of government. BTW the US has joined the coal export bandwagon so nobody is perfect.

  11. BilB
    July 22nd, 2012 at 12:04 | #11

    BaaHumbug,

    You clearly do not have the ability to even read your electricity bill properly. Give it a go, get out your electricty bills going back a few years, or use your neighbour’s bills (I imagine you chuck yours in the bin). It is all there, real evidence of what is going on right under that ring through you nose.

    Hermit,

    You should really start to prepare your thinking for the most probable outcome of this coming election, another minority Labour government. See, you did not think of theat possibility did you. Abbott has so poisoned the waters of cooperation that if there is a hung parliament it will be a very short negotiation period with a predetermined conclusion.

    I’m expecting this contest to be an all smoke without mirrors election. Nothing focusses the mind on Climate Change like having your house burnt down. Here we are heading towards August and in Penrith it is Summer. Take a look at the graph

    http://www.bom.gov.au/climate/current/soi2.shtml

    check out the nose dive into el nino. That coupled with how Climate Change is intensifying the climate systems says pretty clearly that there will be devastation where a fire gets underway this summer.

    Prime Minister Gillard, re-elected will have a lot work to do putting Australia back together.

    So, Hermit, what do you think of my new campaign to have gun owners pay into a compulsory third party personal insurance programme to pay the costs of the victims of guns, as we do for cars?

  12. TerjeP
    July 22nd, 2012 at 12:14 | #12

    Baa Humbug – the reason the carbon tax has been a hard sell is in my view due to three factors:-

    1. Flip flops by the ALP
    2. Lies and deceit by the ALP
    3. The decision to spend a large slab of the revenue on Green Schemes rather than return it via reductions in other taxes.

    John Howard implemented MRET with barely a whiff of objection. And yet it is far more destructive than a simple revenue neutral carbon tax. To be sure there has been an active campaign against the carbon tax by ALP opponents but if the ALP didn’t have the three problems I listed above then I doubt that campaign would have the traction it now does.

    The most simple way to introduce a basic carbon tax without all the fuss would have been to repurpose fuel tax as an environmental initative instead of as a road funding device. It could then have been lowered and broadened to include fuels used to make electricity (like coal and gas) and fuels used in mining and agriculture. It wouldn’t have been perfect but it would have been politically much simpler.

  13. BilB
    July 22nd, 2012 at 12:15 | #13

    Dr Chemical,

    Everyone has a thermometer that measures 5 degrees C (extra), and that is what they will need in just a handfull of decades from now if we lose the fight on CO2 emissions. But what whoever is left at that point really will need, is a wall to hang their thermometer (likely to one of a handful of prized possesions) on. That will be much harder to achieve. Probably a cave at that point will be the safest.

  14. BilB
    July 22nd, 2012 at 12:38 | #14

    Off topic.

    A quick look at for the US, gun related deaths equal car related deaths. For Australia car deaths are about half that for the US, but surprisingly gun deaths equal two thirds of that number. Now considering that gun ownership is relatively rare in Austalia, to that high a total means that the handful of gunowners are really clumsy.

    So gun owners can all soon anticipate paying $200 per year per gun in third party personal compulsory insurance. And victims of gun crime and their families can finally look forward to proper compensation for their suffering.

  15. TerjeP
    July 22nd, 2012 at 14:00 | #15

    BilB – on what basis do you claim that firearms are rare in Australia?

  16. BilB
    July 22nd, 2012 at 14:06 | #16

    I said relatively rare, Terje, meaning I personally know no-one who owns one, whereas I do personally know several Americans who own them. Relatively. I am willing to bet that a study of the official numbers would bear that out.

    Do you own a firearm, Terje?

  17. Hermit
    July 22nd, 2012 at 14:11 | #17

    @BilB
    El Nino could save Gillard the same way it helped Rudd back in 2007. If the public finds both major parties wanting on climate change perhaps they could go Green, though I suspect the Greens have lost both charisma and common sense absent Bob Brown.

    Suppose by next election we have lost a pissweak 5-10 Mt of emissions which is not on track for what climate scientists think should be at least 100 Mt in absolute terms between 2000 and 2020. Who can keep supporting the Gillard polluter-gets-paid plan? Abbott might allow nukes which some current senior govt MPs (eg Albanese, Conroy, Cameron) plus Greens will block. Then again Abbott sees no problem with coal.

    Since my neighbours like to go spotlighting at 1 a.m. I’ve gotten used to gunfire. The US should not only have a gun buyback but also find an alternative term to ‘gas’ for liquid motor fuel. I suspect that the crazies who do the massacres seldom get guns through orthodox channels therefore any insurance claims could be voided.

  18. TerjeP
    July 22nd, 2012 at 14:33 | #18

    BilB – from memory the Australian Institute of Criminology study done a while ago showed that one in ten Australian households had one or more guns.

    I don’t own a firearm. However I have been shooting in the last twelve months and so has my 11 year old son. I think that our gun phobia is a strange social phenomena.

  19. BilB
    July 22nd, 2012 at 14:39 | #19

    The illegals will always be so. The insurance is for the 90% of firearms and the consequences. There are those who drive cars illegally, too. What the policy will mean is that all victims of gunshot incidents will get treated and Australian and US health insurance costs will go down a little bit (for the US a lot).

    The cost of the insurance will reduce gun ownership with out infringing on those all important “rights”. The gun lobby in the “user pays” US economy will not have any reasonable recourse.

    BaaHumbug (perhaps to his credit) must be off looking up his electricity bill. Lets hope that he takes up his findings with Bolt, not that he would get published for his efforts.

  20. BilB
    July 22nd, 2012 at 14:47 | #20

    As I said, Terje, the firearms death toll from that small gun holding is surprisingly high at two thirds of the road death toll.

    I don’t think that Australia has a gun phobia, it is that we have more gun sense. There is a difference.

  21. TerjeP
    July 22nd, 2012 at 16:51 | #21

    As I said, Terje, the firearms death toll from that small gun holding is surprisingly high at two thirds of the road death toll.

    Annual firearm deaths for Australia is about 250 on average although it jumps about year to year. Road toll annually is about 1300. So your figure of two thirds is way too high. The correct figure will be closer to one fifth.

    90% of households have no guns. 10% of households have no cars. You can still make the argument that guns are therefore more lethal than cars but the effect is not as large as you have implied.

  22. bananab
    July 22nd, 2012 at 17:28 | #22

    So after all the to-and-fro Prof. Jones has confirmed a temperature reduction of 0.0038 which is what Mr. Bolt said right at the start, perhaps an apology would be in order. Other scientists have calculated smaller decreases, eg. Prof. Mathews 0.00024 and Dr. D. Evans 0.0007. The climate commissioner (Prof. Flannery) is either incapable of calculation an estimate or more likely too ashamed to admit how small the figure is. I suspect that applies to Steffen, Combet and Gillard also.
    But the real people can all agree it is a piddling and insignificant temperature decrease for an enormous cost. But moreso is the fact that the small reduction in Australias emissions will be dwarfed by the increase in emissions from other counhtries such as China, India, Brazil and other countries

  23. BilB
    July 22nd, 2012 at 17:30 | #23

    Well it was a quick survey, I bow to your more studious appraisal. An insurance policy approach will look carefully at the real figures and costs and arrive at a third party personal figure. The figures on injuries are interesting. Obviously the percentage of gunshot injuries is very different to the figure for car accident injuries (non fatal) and it would be interesting to see the serious injury comparison.

    The notion of an insurance policy approach is really a reaction to the crazy situation in the US where the gun lobby have the politicians stitched up on gun control. The best you can hope for in that environment is to find a monetary deterent. And the best approach towards that end is to require the gunslingers to pay for the damage that they cause.

    The same logic, though, fits for Australia, where a significant share of the beneficiaries of the scheme will be the gun owners themselves, the ones who shoot themselves in the foot, that is.

  24. BilB
    July 22nd, 2012 at 17:56 | #24

    bananab,

    Roger Jones calculation, though, scientifically based is certainly conservative. I had a look at this from another direction, and that was to see what the economic impact of no action would be. The curious thing is that it seems that the economy falls over at a very shallow temperature rise. From that perspective the perceived small impact of Australia’s CO2 emissions reductions is amplified.

    Conversely, your claim of “an enormous cost” is blown out of all proportion and completely disregards the many positive contributions that the Carbon Price makes to the Australian economy. Once the intense negativity of the religious right fanatic Tony Abbott has been removed from the economy after the next election when his defeat leads to his being dumped from the Coalition and he withdraws from politics altogether, Australian industry will surge forward on a wave of renewables energy infrastructure investment.

    I suggest that you take a look at what is happening right now to the US farming belt. A severe drought has set in and is demolishing there productive capacity with average temepratures 5 degrees higher than normal. This has come on very rapidly. It was only several years ago that many of these areas were experiencing 1 in 1000 year rainfalls just months apart.

    You, no doubt, think that you are defending against some great wrong, but you are infact serving to create certain economic catastrophy beyond your wildest imagination. you might care to read all that Roger Jones has published on Climate Change, not just the one sentence that serves your momentary argument.

  25. Baa Humbug
    July 22nd, 2012 at 19:02 | #25

    @BilB
    Like I said, grow up if you wish to have a civil discussion.

  26. Baa Humbug
    July 22nd, 2012 at 19:06 | #26

    @TerjeP

    Baa Humbug – the reason the carbon tax has been a hard sell is in my view due to three factors:- etc etc

    You may well be right.
    I personally am not convinced that CO2 is the devil its made out to be. Colour me sceptical.
    And just like I exercised my right to vote against Howard for sending us to a useless war based on lies, I reserve my right to vote against any party that introduces a tax (however large or small) based on flimsy evidence and one which will never achieve what it’s supposed to achieve.

    Ain’t democracy grand?

  27. Freelander
    July 22nd, 2012 at 19:23 | #27

    Colour me skeptical, surely you mean just plain dumb? Deniers have to be assessed as stupider by the hour as the evidence accumulates adding to what has already been a long overwhelming scientific case for the reality of AGM and the role of greenhouse gases. Many are fools,but no other fool but the climate change denier is so valiant in demanding that the rest of the world acknowledge their foolishness!

  28. TerjeP
    July 22nd, 2012 at 19:27 | #28

    Baa Humbug – I work in the coal sector and I would hardly do so if I thought CO2 was evil in the way it is characterised by some. I also will vote against Labor (I’ll vote 1 for the LDP) in a big part due to their dishonesty. I was hopeful in 2007 that Labor would prove it’s critics wrong but in fact it has been vastly worse than I expected. Which is a pity because the Liberals are not such a thrill at times either.

  29. TerjeP
    July 22nd, 2012 at 19:34 | #29

    Freelander – the role of CO2 in Greenhouse warming is modest. To get any decent warming from an increase in CO2 you need to assume a number of strong positive feedbacks. The existance of these has never been proven but is merely inferred from the historical CO2 and temperature trends. There is still plenty of room for debate regarding temperature sensitivity with regards to CO2 and other emissions. Calling people dumb does not advance the debate.

  30. Fran Barlow
    July 22nd, 2012 at 19:44 | #30

    @TerjeP

    the reason the carbon tax {price} has been a hard sell is in my view due to three factors:-

    1. Flip flops by the ALP

    There have been one on this policy, with the arguable exception of the “citizens assembly”. That hardly rates a mention. Allowing it to be called a tax opened the door to trolling of course.

    2. Lies and deceit by the ALP

    There were none, on this policy.

    3. The decision to spend a large slab of the revenue on Green Schemes rather than return it via reductions in other taxes.

    It wasn’t a large slab, and I suspect that has been the most popular part. Abbott is proposing, in theory at least, to spend a large slab of revenue on “green” direct action schemes.

    Most of the money is being handed back in rebates. Some is being handed out as free permits — and although I regard this last as poor policy, it’s not that unpopular.

    People have been led to believe that this will change their lives radically for the worse and falsely invited to imagine that the government lied about it. “there will be no carbon tax”. When they discover that the scare is baseless and that reversing the CEF means handing back their threshold allowance, one supects they will notice that there was no lie nor even a breach of promise.

  31. Fran Barlow
    July 22nd, 2012 at 19:52 | #31

    @TerjeP

    I work in the coal sector and I would hardly do so if I thought CO2 was evil in the way it is characterised by some.

    Classic strawman … “evil”. This is what happens when you spend too much time in the Boltiverse.

    To get any decent warming from an increase in CO2 you need to assume a number of strong positive feedbacks. The existance of these has never been proven but is merely inferred from the historical CO2 and temperature trends.

    Yes … that’s how science works. One shows proof of principle. Then one examines data and makes inferences. One tests alternative hypotheses and rules them out as they fail to explain observed trends. Charney sensitivity has been very well specified for some decades now. Hansen’s 1981 forecast has been borne out.

    No literate person who has read the science could declare as you have, so you’re either dissembling or haven’t read the science or haven’t understood it. I regard “dumb” as an undesirable term on a number of grounds, but that still leaves us to characterise your stated views above.

  32. Baa Humbug
    July 22nd, 2012 at 20:00 | #32

    @TerjeP

    Thanks for the chat Terje.
    No point commenting any further on this blog. The locals seem quite angry that some people such as myself don’t agree with their views, shock horror.

    Professor Quiggan, nice company you keep here. good luck with your blog.

  33. Freelander
    July 22nd, 2012 at 21:17 | #33

    Hard to be angry with fools Baa. Doubt that you can help it that you’re a fool. So no anger, only pity.

  34. Freelander
    July 22nd, 2012 at 21:26 | #34

    Only a fool debates a fool, Baa. Ridiculing not debating is the way to deal with fools. The only person who can solve a fools foolishness is the fool. Step one the fool has to recognize that they are a fool. When the laughter at their stupidity is loud enough, one hopes they get the hint.

    One lives in hope.

  35. BilB
    July 22nd, 2012 at 21:37 | #35

    Terje, I can’t believe that you said that. Making a living with carbon is what we all must do for the time being, but deluding oneself of the implications is another thing altogether.

    Humbug, you didn’t actually make any comment here, so Baa Baa.

  36. Troy Prideaux
    July 23rd, 2012 at 14:55 | #36

    Channel surfing over the weekend, I somehow landed on 10 to see the last 5mins of the Bolt Report. Surprise Surprise, he was blabbering on about this issue, but Gillard was the target this time.

  37. Freelander
    July 23rd, 2012 at 16:42 | #37

    Bolt is laughing all the way to the bank. He’s probably unconcerned with the truthiness of his waffling. As long as supporters and foes keep his ratings up he can continue to turn controversy into cold hard cash.

  38. Troy Prideaux
    July 23rd, 2012 at 16:58 | #38

    @Freelander
    Absolutely. What’s more, he’s just an ideological mouthpiece for the Murdochs, Rineharts etc pulling the strings at the respective media corps to fashion BS into fact for that particular willing herd.

  39. Freelander
    July 23rd, 2012 at 19:53 | #39

    Rinehart has to have been cleverer than the Packer kid. He took his inherited fortune and gave it a quick hair cut by using his talent to choose a series of dismal investments; she simply held on to what she inherited and waited for the Chinese to make her the richest woman in the world. Be interesting to see how clever Murdoch’s brood will be after he leaves what he can’t take with him and moves to the upper house (or should that be lower house?).

  40. BilB
    July 24th, 2012 at 05:50 | #40

    A scientist on politics on science……

    http://profmattstrassler.com/xotica/hurriquake-2011-what-are-the-chances/

    a very good read

  41. TerjeP
    July 24th, 2012 at 10:53 | #41

    Yes … that’s how science works. One shows proof of principle. Then one examines data and makes inferences. One tests alternative hypotheses and rules them out as they fail to explain observed trends.

    Agreed.

    Charney sensitivity has been very well specified for some decades now.

    Charney postulated a sensitivity figure between 1.5 °C-to-4.5 °C for a doubling of CO2. There is a big difference between the top and the bottom of the range. To say it is well specified and has been for decades depends a lot on what you mean by well specified.

  42. Freelander
    July 24th, 2012 at 15:11 | #42

    Terje, font of scientific knowledge and wisdom. I think not.

  43. Fran Barlow
    July 24th, 2012 at 17:03 | #43

    @TerjeP

    Charney postulated a sensitivity figure between 1.5 °C-to-4.5 °C for a doubling of CO2.

    Actually Charney (1979) proposed 1.65 °C-to-5.2 °C … Calculation from direct physical evidence since that time have put the sensitivity towards the middle of that range. Thus Lorius (1990) {3.0 °C-to-4.0 °C} Hoffert (1992) {1.4 °C-to-4.2 °C} Hansen (1993) {2.0 °C-to-4.0 °C} Chylek (2007) {1.3 °C-to-2.3 °C} Tung (2007) {2.3 °C-to-4.1 °C} Bender (2010) {1.8 °C-to-4.1 °C} Schwartz (2010) {0.9 °C-to-3.9 °C}. The feedback assumptions account for most of the variability, but even at the minimum end, the consequences are quite dramatic. It’s not going to be trivial. Moreover, as the perturbation from CO2 is likely to last on most estimates for several tens of thousands of years, absent some drawdown technology or some you beaut geoengineering with unknown consequences, the temperature will remain significantly elevated with all that entails for at least some centuries after humanity stops being a net contributor to atmospheric concentrations of CO2. The consensus position assumes a minimum warming close to 2 °C for a doubling of atmospheric CO2 with a most likely value of 3 °C. 4.5 °C is not excluded. So we get to choose between very difficult, disastrous or catastrophic. bear in mind also that unless we act, doubling (560ppmv) is on the low side. Under b-a-u we are looking at 750ppmv by 2050. If we don’t act early we may get it anyway as the Arctic permafrost decomposes and starts a new round of positive feedbacks.

    Uncertainty, such as it is, is not humanity’s friend here.

  44. Nick
    July 24th, 2012 at 20:22 | #44

    “There is a big difference between the top and the bottom of the range.”

    As I understand it, one would more or less completely wipe out life as a result of methane gas explosions 100,000 times more ferocious and destructive than the world’s entire stockpile of nuclear weapons, and enough hydrogen sulphide released from the oceans to fatally poison the world’s population 1000 times over.

    The other would simply displace 100s of millions of people as large swathes of the northern hemisphere turn to dust bowls, and our sea levels rise by 5 to 6 metres.

  45. Fran Barlow
    July 24th, 2012 at 20:49 | #45

    @Nick

    Not sure about the comparisons at the catastrophic end but it’s very clear that the planet could become pretty much uninhabitable by the vast majority of humans over time and the rest would be living at a fraction of their comfort. If the clathrate gun hypothesis is borne out matters get even worse. There are scenarios in which these seas become emitters of toxic sulphides, wiping out most of life.

    Presumably, human societies would act before these scenarios became unavoidable. (I say presumably because I’m an optimist). The trouble is that the preventive measures would also have unknown consequences and might produce seriously negative unintended consequences. Certainly, biodiversity would crash on land and in the marine environment. The humans that survived would be living on a radically diminished world. Given that this is the only planet in the universe known by us to support life, this would be a tragic existential irony — being a species with the wit and the resources both to author catastrophe and to prevent it but impeded by its own usages from doing so until it was too late and the old positions were irrecoverable. I’m reminded of that astonishing but telling climax in that famous 1960s flick, Village of the Damned.

    I remain amazed that deniers and apologists for b-a-u can cite uncertainty as if it favoured their position, when there is no scenario in which the costs of action mact the likely costs of inaction. It’s a position of utter recklessness that ruthlessly mocks the concerns they typically express in relation to balanced budgets and inter-generational debt. Here they wink at catastrophe and smile broadly at disaster.

  46. Nick
    July 25th, 2012 at 09:32 | #46

    Interesting, Fran. Thousands of pop culture references aside, I realised I hadn’t actually seen Village of the Damned, and watched it late last night on Youtube. (I realised then that I’d read the Wyndham book as a child.) The child spells his name with bricks early on…have to give that some thought. Great film.

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