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Contemplating the Global Carbon Budget – nervously

by Kennedy Graham

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’sCollapse.  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 5thAssessment 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.

11/26/2013 – 20:46

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