Contemplating the Global Carbon Budget – nervously

We’d all like to avoid dangerous climate change, especially those under 20.  If you are a bright year-8 school student, you will be at your professional peak in 2050, and a proud, if apprehensive, centurion in 2100.   I shall be dead, but I am equally determined to avoid dangerous climate change.

The quaint thing about climate change is that it is a mirror to humanity – a challenge to global governance.  As Minister Groser has so insightfully observed, it is a global problem that requires a global solution.  The solution is stabilisation of atmospheric gases within a safe time-frame.  We stated that in 1992.

It has taken two decades to agree on a (rough) threshold (2°C temperature rise; 450 ppm volume).  The time-frame for carbon neutrality is more complex – it could be medium-term (2050) or long-term (2100) and the very long-term consequences (2200-2500) would be broadly the same.   Either way, the critical thing is a limit to the amount of gases emitted into the atmosphere.  Essentially, this means a global carbon budget.

Agreeing on a global budget comes as a shock to a carefree species that has gone forth and multiplied – possibly to excess.  The notion of budgetary constraints is foreign to the DNA – read Jared Diamond’s Collapse.  The rational mind tells us that it is, from today, an imperative.  Emotional IQ prompts hesitation.  Providing for the kids today still trumps ensuring that the kids can provide for theirs, tomorrow.  There’s the rub.

The Framework Convention of 1992 looks both back (‘historical responsibility’) and forward (‘CBDR’; ‘respective capabilities’).  But it did not mention a global budget as such.

In the past five years, the global budget has become the litmus test of the global bargain—yet to be struck.  The IPCC introduced it, in an elliptical way, in its 4th Assessment Report, of 2007.  To stay within the temperature threshold, the North would need to collectively cut emissions by 25% to 40% off 1990 by 2020.  But that was somewhat short-hand since it was not placed in the context of an explicit global budget.

The Global Budget got its debut in various form in 2009, in preparation for Copenhagen.   WWF and others produced a draft treaty that would cut annual global emissions to 44 Gt. in 2020, 36 Gt. in 2030 and 7 Gt. in 2050.

But the idea of a long-term, period-bounded global budget belongs to the German Advisory Council on Global Change (WBGU). Other research institutes – PIK, Climate Analytics, Ecofys – along with their coy Chinese counterparts – are doing the number-crunching, with increasingly sophisticated modelling.  The WBGU kicked this thinking off as early as 1995; its report of 2009 remains the standard-setter.

But the issue is not simple.  First off, what is your budget period?  Some will say 1750 to 2050.  Others favour 1750 to 2100; others 1990 to 2050.

If you take 1990-2050 as WBGU has done, the budget is 1100 Gt. CO2.  In the first 20 years (1990-2009), 500 Gt. have been emitted (25 Gt. p.a.).  This leaves a budget for 2010-50 of 600 Gt. (15 Gt. p. a.).  This is the budget for a 75% chance of staying within 2°C.  Lengthening the odds to 67% increases the budget to 750 Gt.  No-one in their right mind would risk their personal or family health to the tune of 33% or even 25%.  But this is what we are doing with the planet.

To quote WBGU, “the era of an economy driven by fossil fuels will definitely have to come to an end within the first half of this century”. As a result: “it is of paramount importance that the level of global emissions reaches its peak by the year 2020 at the latest, because otherwise the reduction of emissions in the subsequent period would have to take place at a speed that that would fully overstrain the technical, economic and social capacities of our societies”.

For its part, the IPCC has, for the first time, explicitly addressed a global carbon budget in its recent 5th Assessment Report. It talks about a budget, of all gases, of 1,000 Gt. since 1750. It does not specify an end-year, presumably because that is less critical to the science than the politics. And it concludes that half has already been emitted by 2011. This is simply Working Group I, so it remains to be seen how much more detail might be conveyed by Working Group 3 next March.

Second, and toughest of all politically, how do you divvy the global budget up?  WBGU identifies two optional methods.

–          Method 1. Historical Responsibility: This includes the 60 years from 1990 to 2050. The developed countries bear huge responsibility for that past twenty years – a few are already ‘carbon bankrupt’, i.e. with no rights to emit over the next 40 years. This, of course, is politically unfeasible.

–          Method 2. Future Responsibility: This separates the 60 years into two periods: the past (1990-2009) and the future (2010-50).  For the past, developed countries simply pay cash compensation to the developing countries.  For the future, the carbon budget is apportioned on a per capita basis. The annual allowance for each global citizen is 2.7 tonnes.  But a trading mechanism can allow some flexibility.  Three groups of countries are identified: Group 1 with 60 countries that are above 5.4 t. / p.c; Group 2 with 30 countries between 2.7 and 5.4 t./p.c.; and Group 3 with 65 countries with less than 2.7 t./p.c.

This, of course, is light-years away from the bland, if not banal, diplomatic negotiations in Warsaw last week.  But this kind of analytical work is being done just down the road – in Berlin and in Potsdam.  The negotiators need more of it – in fact they are starved of it.

What does all this mean for New Zealand?  The present Prime Minister was sceptical of climate change as recently as 2005.  The Finance Minister thinks that Kiwi famers have always known climate change and will cope.  The Transport Minister finds, in 2013, the idea of anthropogenic climate change an ‘interesting prospect’.  These, not to put too fine a point on it, are not your average global thought leaders.

So don’t expect much from NZG on the global carbon budget.  What is New Zealand’s 2050 target?  A 50% cut off 1990.  Yet we fiercely assert that we are doing our ‘fair share’, and woe betide any deniers.

Setting aside the present NZ Government, the world will soon take on a global carbon budget, not because it is easy but, to cite President Kennedy, because it is hard – and above all, because it is necessary.  We did not really have to go the moon in 1969, but we do have to have a global carbon budget, half a century later, in 2019.

10 Comments Posted

  1. spam – there is so much LPG combined with our natural gas that we have to import it to meet our winter demands. There may be hundreds or thousands of years of natural gas reserves at our current rate of consumption, but there isn’t that much LPG.


  2. Spam – Peak Oil showed up when and where expected. It has been variously redefined to try to make it appear as though it didn’t happen, but it did and the price of oil remains where the next available technology put it, and will stay high compared with the 60’s until the demand heads towards zero.

    Natural Gas will have a similar trajectory – Fracking doesn’t alter the physical and economic realities of such resource peaks… though your final statement rings sort of true. “People won’t go cold” because if we burn all we know we have the warming of the planet from the CO2 will render substantial chunks of the part we can live on now, uninhabitable.

    In other words, even if you find the gas to burn, you run out of CO2 budget to be able to burn it.

    Thousands of years? I’d have thought at most one of those thousands but I have NOT studied that number, partly because I know that others do and mostly because the CO2 budget is enough of a limiting constraint. I would be interested in what it is estimated to be exactly though.


  3. @Trevor: LPG comes predominantly from gas, not oil, so “peak oil” (which is wrong anyway) is irrelevant. And fortunately there are thousands of years of gas reserves left, so people won’t go cold.

  4. A look at a new housing development with gas bottles (LPG down here in the south), gas fires and probably gas water heating and hobs doesn’t fill me with confidence that the builders, purchasers and government have understood the implications of global warming or peak oil. What I didn’t see was any sign of solar water heating.

    We have a long way to go.


  5. I was recently re-reading James Hansen’s book. It looks like something less than 350 ppm of CO2 might be safe, if the non-CO2 GHGs can be decreased. We’re at nearly 400 ppm CO2 now, with other GHGs also increasing. I still see no sign of actions to slow, stop and then reverse the level of CO2 emissions, or other GHG emissions.

    You may not think we need to decrease CO2 emissions to zero very quickly but that is just your opinion, Trevor. As soon as we do, of course, most of the world starves to death. Yes, some of the world won’t let it get that bad but it will already be pretty bad well before then.

    Get on with it? Well, that would be wonderful, wouldn’t it? Or perhaps not.

    Anyway, we definitely need to get emissions down to zero ASAP. Unfortunately, the “P” in “ASAP” usually gets defined as “what is politically acceptable”. Sure, it might be possible to plan a slightly less than catastrophic path down, so let’s get on with that, but let’s not fool ourselves that there is any kind of strategy that will be acceptable to all.

  6. No Tony. Your position was basically helpless. My position is that we still have a chance. If there is no hope, then you might as well give up worrying. What I am saying is “keep worrying!” but also “get on with it”.


  7. Trevor,

    OK, so there is lots we can do. No need to worry, eh? It may be difficult but we’ll get it done. Thanks for ridding me of my concerns.

  8. Tony – it isn’t necessary or practical to drop our CO2 emissions to practically none from now on. We need to drop them soon, and get them down to somewhere near none by 2050 or so, but there is less rush to get them down to practically zero.

    Even if we do overshoot the 450 ppm or whatever limit is accepted, we still will have an opportunity to reverse this before the full temperature rise is felt. It is possible to go into negative emissions, but it is harder work. For example, we could turn biomass into charcoal and dig it into the ground. We could bury trees in old coal mines. We could burn biomass e.g. in power stations and bury the CO2 using CCS and old gas fields. We could reforest some areas.

    However we need to get our economy off a fossil-fuel base first.

    It would of course be easier to leave the coal, oil and gas in the ground rather than overshooting the limit, but it doesn’t look as if humanity will choose that easier option.


  9. The fact that “It has taken two decades to agree on a (rough) threshold (2°C temperature rise; 450 ppm volume).” is very worrying. That limit has been shown to be too high, with dangerous effects now likely to kick in at much lower temperature rise (1.5 or less). So having taken 20 years to reach agreement on an obsolete limit, will it take another 20 years to realise that the limit needs to be much lower? With the surface temperature rise now 0.89C, that doesn’t leave a lot of wiggle room for getting the earth back to energy equilibrium.

    At only 0.89C, ice sheets at both poles are losing tens (or is it hundreds?) of cubic kilometres of ice each year and glaciers are retreating fast, among other troubling effects. If our illustrious leaders actually manage to limit warming to 2C, we’re in for a hell on earth, compared to what humans have been used to for the last 10,000 years.

    You’re right about the end year for a carbon budget not being relevant to the science. The budget relates to the amount of carbon in the atmosphere that will cause a specific forcing thought to ultimately lead to some temperature rise. A very slow temperature rise is preferable to a fast temperature rise, so it’s probably best to put an end date of, say, 1 million years hence on it. That would mean humans need to put out miniscule amounts of carbon into the atmosphere each year, from now on.

  10. Great work Kennedy. It seems to me that the only way we will get constructive buy in in carbon reductions is if we see what it means for us. Calculations that show what our per annum fuel usage might average at, plus our consumption of various carbon producing items such as electronics, clothes, food , household products may get us realising what we can do.
    The 50% of 1990 usage is a way of calculating this, and thank goodness we have more choice of organic products and energy efficient alternatives now.
    By doing this sort of analysis we can see if we have to cut out luxuries such as air travel, or seriously ration it, maybe even rationing non work vehicle usage??

    I am presently being forced by health issues to change my work direction, and maybe even retire early and working on this sort of stuff would seem a socially useful way of spending time.

    Who is doing this sort of thing now??

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