11 September 2009

Forget about 2050, we're blowing the carbon budget right now

by David Spratt

Sick of hearing about greenhouse emission reduction targets for 2020 or 2030 or 2050? Now there's a new way to think about what we need to do in Australia, and its a million miles from the Canberra debate: The carbon budget for Australians to 2050 for a 2-degree target runs out in five and a bit years!

Focusing on targets decades ahead has a bad side to it, because it transfers responsibility for action to the future, rather than the here and now. Perhaps that's why the 10:10 campaign in the UK has picked up such a groundswell of support so quickly, because its action time horizon is the next year.

As the world head towards COP15 in Copenhagen this December, the question about how far / how fast emissions need to be reduced is always lurking. The mainstream public debate is still focused on the Kyoto Annex 1 (advanced industrial economies) reducing emissions by 25-40% compared to a 1990 baseline by 2020. But that is the wrong target and the Australian governments proposed Carbon Pollution Reduction Scheme won't reduce Australia's actual emissions below the 1990 level for another quarter of a century.

And there are some startling new figures about what we need to do, right now. Earlier this year this blog looked at two new research papers published this week in Nature on emissions targets.

One paper looked at how much carbon "budget" was left to 2050 to keep warming to 2 degrees. Now 2 degrees is not a good idea, but the results were sharp. They found that almost a third of that budget had been used in the first 8 years! From that work, a number of conclusions can be drawn:
  • If emissions keep growing at 3.5 per cent a year, then the carbon budget for 2 degrees runs out in 2021. That is, after that time, emissions would need to drop to zero immediately to have a 75 per cent chance of not passing 2 degrees.
  • If global emissions reduce 2 per cent a year from now, the carbon budget will run out in 2030 for 2C, and
  • With a 4 per cent annual reduction in global emissions, it will run out in 2040.
And in would take a miracle for COP15 in Copenhagen to produce a result that would even stabilise global emissions at their current level by 2020, in which case COP15 will blow the carbon budget to 2050 for 2 degrees in less than 20 year from now.

And that for a target that will that initiate large climate feedbacks in the oceans, on ice-sheets, and on the tundra, taking the Earth well past significant tipping points. Likely impacts include large-scale disintegration of the Greenland and West Antarctic ice-sheet; the extinction of an estimated 15– 40 per cent of plant and animal species; dangerous ocean acidification; increasing methane release; substantial soil and ocean carbon-cycle feedbacks; and widespread drought and desertification in Africa, Australia, Mediterranean Europe, and the western USA.

Now there's an even more compelling way to look at the issue, thanks to Potsdam Institute Director Hans Joachim Schellnhuber in The Guardian of 10 September: Developed countries are 'carbon insolvent'.

Applying his logic to Australia...
  1. The total carbon budget 2050 to have a 2-in-3 chance staying below a 2-degree temperature increase is 750 billion tonnes of carbon dioxide (CO2).
  2. If you take the world population now at 6.9 billion people (and assume no population increase!) and...
  3. Then assume that the world's population has an equal right to emit carbon (a starting point which ignores historic carbon debt and responsibility), then...
  4. The carbon budget per person to 2050 is 110 tonnes CO2 (750 divided by 6.9). Of course if you allow for increasing population (estimated at 9 billion by 2050), that figure is lower.
  5. We know that Australia emissions today are 20.58 tonnes CO2 per person per year, the world's highest per capita carbon dioxide emissions from energy use.
  6. Divide that budget of 110 tonnes by the yearly figure of 20.58 and the result is that:
  7. The carbon budget for Australians to 2050 for a 2-degree target runs out in 5 and a bit years!
Or do we reckon that we have some inherent right to pour more CO2 into the air that the billions in the developing world who lack the infrastructure and standard of living that our historically high emissions have bought us?

SEE also discussion in Sydney Morning Herald: Lost opportunities from the crisis.