Zero net emissions by 2050 – preferably sooner

I’ve just sent my submission on the NZ government’s intention to make a formal commitment to a target of a 50 percent reduction in net greenhouse gas emissions by 2050 to the Ministry of the Environment — barely squeaking in before the published deadline. My original intention was to submit a closely argued case for a more aggressive target, but recent events militated against that. I settled for something a little more pithy, with an offer to back up my points with an oral submission if necessary. I’d also like to credit Bryan, whose incisive post on the recent “Beyond “dangerous” climate change” paper by Anderson & Bows makes a compelling case for a revision in the international received wisdom on acceptable targets. Full text below the fold…

I wish to oppose the gazetting of a target for a 50% reduction in New Zealand’s net greenhouse gas emissions by 2050, on several grounds:

  • Because it is inadequate, and fails to reflect current scientific understanding of the magnitude of the climate change problem confronting the planet.
  • Because it fails to take into account the “first mover” economic advantage in adopting low carbon policies, and because “locking in” high carbon emissions by featherbedding agriculture and protecting big emitters is a long term liability for the country and its taxpayers.
  • Because climate change is not purely a scientific or economic problem, but has moral and ethical dimensions that have intergenerational implications.
  • Because the risk of doing too little is far greater than doing too much.
  • Because the target is badly out of line with indicated targets from other advanced economies.
  • Because New Zealand’s emissions profile, coupled with our unique mix of energy resources, gives us an opportunity to position ourselves at the forefront of countries taking action on climate change, thus enhancing our “clean & green” image and ensuring a sustainable future for all our businesses. A target recognised as weak — as “50 by 50” surely will be — will compromise that future.

I would support the gazetting of a 2050 emissions target that takes into account the reality of the situation that confronts us. That means zero net emissions at a bare minimum — preferably resulting from a strategic pathway to net negative emissions as soon as is feasible.

Should the minister wish to hear oral submissions, I would be delighted to make one by telephone or video conference.


I refer the Minister to this recent paper: Beyond ‘dangerous’ climate change: emission scenarios for a new world, Kevin Anderson and Alice Bows, Phil. Trans. R. Soc. A 2011 369, 20-44 doi: 10.1098/rsta.2010.0290 (available free here), in particular this section of the abstract:

The analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2ºC. Moreover, the impacts associated with 2ºC have been revised upwards, sufficiently so that 2ºC now more appropriately represents the threshold between “dangerous” and “extremely dangerous” climate change.

The Anderson & Bows analysis is worth reading in full. It reinforces the view that current international thinking on targets is badly out of line with what science is now telling us. To adopt an intentionally low target in the face of the evidence amounts to gross dereliction of duty. Not, perhaps, a legacy this government should aspire to.

A comfortable assumption that we can “live with” 2ºC is no longer warranted. To achieve any kind of long term climate stability, we will have to move beyond cutting emissions to removing carbon from the atmosphere. A nation that assumes it can continue carbon emissions in the long term — as implied in the framing of a “50 by 50” target — is making a profound strategic mistake. To maintain a planet with ice at both poles means trying to limit atmospheric CO2 to 350 ppm or less (Hansen et al, Target Atmospheric CO2: Where Should Humanity Aim? 2008). We are currently at 390 ppm and rising rapidly.

At some time in the near future, economic prudence is going to be trumped by the necessities of survival — as some of us in Canterbury have recently discovered. I am heartened to discover the government agrees, and would wish that it apply the same thinking to our long term survival and not just tectonic misfortune.

30 thoughts on “Zero net emissions by 2050 – preferably sooner”

  1. I have been reflecting that targets in NZ may be confused by the lumping in of methane release from farms. CO2 is long lived and cumulative. Methane is short lived (10 years) and although it breaks down into CO2 that is trivial compared to the volume of CO2 we emit directly. See here an article by ray-pierre on Dec 6:

    Methane really becomes a serious issue if its release from tundra, and even larger ocean sources, is triggered in quantity by CO2 induced warming. With respect to farming in NZ it may be used only as a do-nothing-yet diversion.

    No one should be exempt CO2 emission disincentives, whatever the industry. Nor should anyone be ruled out on incentives for conversion to sustainable practices.


    1. Noel, although methane breaks down to CO2, this CO2 part of the methane cycle should only be included as an anthropogenic GHG for fossil methane.

      In the case of methane from cows and sheep, the carbon in this methane that will become CO2 is from the grass, which has sequestered it from the atmosphere. So there is no net increase in carbon dioxide from the atmosphere (in fact there is a decrease for the 8.5 years the methane takes to turn back in CO2). This is much the same as the use of bio-mass: although burning biomass will create CO2 emissions, these are equal to the CO2 sequestered by the plants used, so not a net CO2 emission.

      In the case of fossil methane the carbon dioxide has been trapped underground for a long period of time. When the methane is released, and eventually breaks down into carbon dioxide, the atmospheric concentrations of CO2 go up.

      1. Your point about agricultural methane is very misleading, because what the animals do is convert carbon to the highly effective greenhouse gas methane — defined as having 25 times the warming effect of CO2 over 100 years. So although it’s not “new” carbon, it has a high warming effect, and as such needs to be taken into account.

        1. Some questions I have regarding methane are
          (a) are the net levels of CH4 from ruminant animals actually increasing globally?
          (b) Why do we account for CH4 but not the CO2 sequestered in the pasture?
          (c) Is NZ the only country to include agriculture in its ETS, and why?

          I would be onboard with decarbonising NZ industry where possible, but agriculture looks like a real sticking point to me.

          1. b) Most of the CO2 in the pasture (well CxHxNxXx) is released back to the air within a short time frame, through either cow respiration, dung, human consumption of meat and milk, and disposal of cow carcases. The C not consumed by the cow is released by plant decay.

            If this was accounted for in the same way that forest carbon is it would require farmers to either buy or receive credits based on the change in carbon stock. As the long term change in neutral there would be no point.

            There is of course the argument that some C remains in the soil – soil carbon. This is an issue for the future, but at the moment the measurement and verification is too prohibitive, especially during the Kyoto period (as we would have to verify national fluxes).

            c) Yes (although it is not actually in the ETS yet). This is because our agricultural emissions are largest as a percentage of our national emissions – so the pressure is highest. Although one could argue this is a fault of the national emissions approach of Kyoto. NZ farming is very emissions efficient – the pressure should come on emissions inefficient farmers first. But due to national accounting our farmers receive the most pressure. If we do have an ETS that places large costs on farmers our production will fall. That will raise prices and cause an increase in production overseas. As that new production is less efficient global emissions will rise.

            1. A good summary R2D2, thanks.

              I still don’t think it is reasonable to penalise NZ farmers on because our emissions profile is skewed to them.

              What we are saying is that, because we are a light industrial nation with a high percentage of renewable energy, we think it is fair to tax farmers as some kind of punishment for our good fortune in other areas

              As you say, production will move offshore and NZ will lose its major industry.

              And I am yet to see a convincing argument that CH4 from ruminants is actually a problem that needs to be solved.

        2. Sorry Gareth, that was not my point.

          In Noels post he says “although it breaks down into CO2 that is trivial compared to the volume of CO2 we emit directly”

          My only point is that the CO2 left at the end of the methane cycle is only equivalent to the CO2 that was absorbed at the start. So it should not be counted. This is not the case for fossil methane.

          As you say, methane itself is a greenhouse gas, and this is more important. But I was not trying to dispute that.

          Note: The choice of including the CO2 effect in methane will add about 2.7 to the GWP (as when methane converts to CO2 it gains mass CH4 -> C02), so it is not a trivial matter. But my understanding is that the situation at the moment is that all methane is treated as biological.

  2. In New Zealand we ran in to trouble with the carbon tax because the politicians included a fart tax which upset the farmers. Without the farmers on board its a dead duck. Forget about the farmers and methane and concentrate on getting rid of coal. When we have enough electrical energy from natural sources we can then start on oil. My guess is that we need to treble our electrical capacity to fulfil our energy requirements so we have a long way to go.

  3. Gareth,

    In terms of what science is now telling us, is there (or are there) a table or list of some ordering of each country’s present and/or likely projected GHG outputs, the nature thereof (animal or human) and so on ?

    Not that I’m arguing this but in big picture terms mightn’t NZ’s 50 percent constitute a prudent figure in relation to whole global outputs?

    1. I’ll have a look for a single source of data on emissions profiles, but the key point depends on your definition of “prudent”. My view is that the risk of doing too much to cut emissions is pretty much zero (ie, I make a strategic judgement that the world will move from not doing much to doing a lot more as climate impacts bite). Sectors of the economy that move towards factoring in emissions costs (and therefore set about emissions reductions) will have a competitive advantage both domestically and internationally at that point. Any short term disadvantage can be covered by targeted government incentives. Sounds easy, eh… 😉

  4. Further to the above – Global SST’s and the Global Temps are already significantly above the pre-industrial values. We now have Climate Scientists finding that the effects of AGW are exacerbating extreme weather events. More examples are:
    2010 being the wettest year globally and more heavy precipitation from an atmosphere loaded with more water vapour.
    The rate of loss of the Greenland Ice Sheet is approximately 20 Gtns per year squared. The current loss being around 200 Gtns per year. This with a average Global warming of around 1 degree.
    We need to remember it’s NOT 2 degrees from NOW. Its much less than that; and yet we have already BUILT IN further warming.
    Further emissions will only exacerbate the problem. We don’t have that much time left, if by good luck (certainly not good management) we stay within the 2 degree target (which year by year is looking less and less a safe target).

  5. @tomfarmer,

    For ‘World carbon dioxide emissions data by country’, try the Guardian’s Data blog,

    They also have Carbon emissions per person, by country;

    And there is always the UNFCCC. They have some charts here
    When LULUCF (land use, forestry) is included, NZ has the second highest growth rate of the Annex I Parties. Ouch!
    Without land use and forestry, NZ has the ninth highest growth rate of the Annex I Parties.

  6. Can someone please explain to me in easy to understand terms why it is that since 1850, the supposed year CO2 concentrations were 250ppm and the start of the industrial revolution and thereby the cause of the increase, we have had 2 periods of warming and 2 periods of cooling and are now in the third period of warming which started around 1983, depending on who to believe. so the CO2 went up all the time but nature did what it felt like taking the temp up and down in it’s own fashion, about every 30 years odd. So why do we now think that it is different? I am all for reducing CO2 and sustainable energy etc. but I am totally confused about the doomsday scenarios of today when nature seemingly did not give one iota about the increasing levels of CO2 since 1850 to 1983.

    1. Tom, the simple answer is that the CO2 effect (or “forcing”) starts out small (defined as zero at 1750 IIRC), and increases gradually as the gas accumulates in the atmosphere. However, there is a lot of natural variation in the climate system — represented by the “wiggles” in the graph — that overwhelm CO2’s effect at first. Over the last 30 years the CO2 forcing has begun to dominate over those natural variations, and so global temperature has moved upwards strongly.

  7. Gee, is tombombadill’s IP address perhaps the same as Tom/Jerry’s, perchance? Such an innocent sounding generic climate question – which has nothing whatsoever to do with the post, and could have been posted on any climate thread. I vote for DNFTT.

  8. To Carey and Palin.
    Not sure what you are on about or what DNFTT means, but my age probably won’t help. I have been sitting in neutral territory on this issue as much as anything since I can still remember the coming ice age hype of the 60’s and 70’s so well. But since it does indeed look like it is going to require financial effort I started to read articles and books propagating both sides of the debate. Sadly for some reason I have not been able to get a satisfactory answer for my question above. If I ask a, as you call them sceptic, I get the “it is all natural” answer but the people I know who feel that it are the manmade issues can’t tell me why it is different this time, all I get is “that is what the scientists say”. Personally I think it is a fair question. And as far as posting it here is concerned I got the impression that this article had to do with reducing CO2 and I am happy to play my part but am having difficulties finding the answers as to why.
    If nobody here knows that is fine, I will keep on looking.

      1. Dappledwater: I agree with you. I’ve seen identical wording from apparently different personas in climate related threads elsewhere.


    1. Whoa, there it goes again!. Tom, Jerry, Tombomadill and now Pat eh?. You must have a drawer full of socks.

      Oh, and a note to any casual reader who comes across this thread (Pat’s sock-puppetry is aimed at you). His question can be easily answered by wandering over to skeptical science

  9. To Dappledwater
    Thanks for the link. I read it before. It goes back too far in time in relation to my question. I don’t think that going back that far is relevant to what we see today. But in my opinion what has happened since the start of the industrial revolution does have relevance. So who is correct Pat or you? (As far as answering, or not, the question, that is)

    1. tombombadil, the best place to start is the IPCC assessment reports. See here, for example, for a discussion of different forcing agents, both natural and anthropogenic.

      Your question suggests that someone has told you that “climate scientists think that CO2 is the only thing that affects climate”. As you can see from the link I gave above, that is not true. You might want to question the veracity of your source.

  10. CTG, thanks for that. Read that also, including most of the assessment reports
    Sadly I fail to see any reference in this that relates to my question. And while that question may or may not be relevant in the greater scheme of things it intrigues me and I will keep searching.

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