Just as children are taught (one hopes) to clean up their own mess as an incentive to avoid making a mess in the first place, so too with carbon emissions: we have a mess to clean up. Political philosopher Henry Shue, speaking at a technical briefing in the latest round of UNFCCC climate negotiations in Bonn, describes the mess like this:
If we want to limit global warming, for example, then, to 2º C above pre-industrial levels, we must avoid emitting the trillionth ton of carbon to be confident of having even a 50% chance of meeting this target. We have already emitted 0.5 Tt C and are therefore already committed to 1º C of warming. “Having taken 250 years to burn the first half-trillion tonnes of carbon, we look set, on current trends, to burn the next half trillion in less than 40”. Recent research suggests that the most helpful way to conceive our challenge, if we want to avoid warming of more than 2º C, is as the challenge of remaining within a total cumulative carbon budget of 1 Tt C, although of course it may turn out that this cumulative cap needs to be revised as time progresses. Total cumulative emissions of carbon must not surpass 1 Tt C or global average surface temperature will, with 50% confidence, rise more than 2 º C above preindustrial levels, due to CO2 alone. As shorthand, then, we can view our challenge as staying within a cumulative carbon budget of 1 Tt C, or avoiding the trillionth ton.
The question is, who is responsible for cleaning up this mess that was largely created by previous generations? It may seem unfair that we should clean up someone else's mess, but neither would it be right for us to leave it to future generations.
Apparently the latest round of negotiations hasn't gone too well, precisely because of arguments about this key point. There are all sorts of issues around equity and fairness and whether developed countries should carry the burden of responsibility because of their historic advantage of having benefited from a carbon-intense industrialisation process.
Given the remaining fixed budget of half a trillion tonnes of carbon that can be released into the atmosphere, it is crucial to recognise that this quantity is fixed for many generations to come. Which means that whatever we use up of that budget now, leaves less for future generations. "We are in direct competition for a scarce resource with our own great-grandchildren, and everyone else’s great-grandchildren." Shue notes that "Over the time-scales that matter to humans, the planet’s capacity to deal with carbon without rises in surface temperature is non-renewable, even if over several centuries the atmospheric carbon will break down." Therefore, "Intergenerational equity is not an additional peripheral aspect of the question that we may optionally take up or not, as we choose; the central question is essentially intergenerational. One budget is shared by us and every foreseeable generation to come."
So which countries and sectors should pay for what they use of this budget, and which should not? Quite understandably, developing countries are pleading for leniency on the grounds that they have not used as much of the historic budget, and are not benefiting now to the extent that industrialised nations are. Shue provides a robust rationale for why the "free" emissions should be reserved for the poorest countries.
The outcome of this issue will have profound repercussions for many countries. If you are at all interested in the debate, I urge you to have a look at Shue's discussion paper. It's brilliant in sweeping aside all the political crap and presenting a coherent argument. At eight pages, it's not too onerous a read.
[With thanks to Harald Winkler for pointing out Shue's paper}
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