Copenhagen and carbon budgets

As Copenhagen heads into week two, most of the talk has shifted to targets and timelines, typically something like X% of emissions by 2020 or 2050, relative to 1990 levels. This dating is a legacy of the German delegation in the lead-up to the Kyoto Protocol in 1997, who wanted a base year of 1990 because their Eastern halves had a post-Soviet industrial crash after 1990, and this made the overall German and European numbers look better. That legacy, however, can be confusing when other numbers from, for example BC’s government, are for cuts relative to 2007 levels.

Targets and timelines on offer in Copenhagen have rightly been criticized as too lax, and say little about the path that will be taken to get to those targets. As a reality check, we need to think about how large is the world’s carbon budget — the total stock of emissions that can be emitted between now and 2050 by everyone, consistent with keeping temperature increase under 2 degrees Celsius — and then how to divvy up those slices.

The World Wildlife Federation put out some updated calculations that put the world’s carbon budget (between now and 2050) at just over 1 trillion tonnes of CO2 equivalent. They estimate global emissions of 46 billion tonnes in 2010, a level at which the total budget would be exhausted in just over 23 years. The WWF then figures out a scenario for salvation: emissions must fall to 7 billion tonnes in 2050, a drop of 80% from 1990 levels; and 1990 levels would be re-achieved by 2020.

Now for the hard part: over the next decade, industrialized countries would do most of the heavy lifting, with a 40% reduction relative to 1990 levels by 2020 (total industrial emissions in 2010 are a hair under 1990 levels so the percentage drop from 2010 is about the same). Developing countries would have their total emissions peak by 2015, and by 2020 would be slightly under 2010 levels (but this is 97% above 1990 levels). By 2050, the split is for a 95% reduction in the industrialized countries relative to 1990; 47% below for developing countries.

These findings approximate a CCPA paper from last year by Colin Campbell and Cliff Stainsby that used the global carbon budget concept to estimate what BC’s fair share of emissions would be (also keeping global temperature increase to 2 degrees Celsius, based on modeling by Andrew Weaver at the University of Victoria). The standard of fairness was equal per capita emissions, and they found that it was essentially impossible to divvy up the full 40+ year carbon budget on an equal per capita basis, as it would require draconian cuts immediately.

As an alternative, the authors figured that BC (and other rich jurisdictions) could converge towards an annual flow of emissions by 2050 that would represent an equal per capita amount in that year and thereafter. This is essentially the same as proposed by the WWF. The answer from this exercise was that BC needed a 94% reduction in emissions by 2050, although in private conversations the authors argue that number is likely higher due to the most recent dismal science on climate change. And BC is already on the low end of per capita emissions for Canadian provinces; the percentage reduction for Alberta and Saskatchewan, our biggest polluting provinces, will of course be higher.

So, think new industrial revolution over the next decades if we are to pull this off. And yet, the political negotiators from the rich countries at Copenhagen do not seem to get it, and if anything assume that we can go slow, and even hive off a big chunk of our emission reductions to developing countries through offset projects. I would agree that we need developing countries to commit to targets, but the political impetus behind this proposal is so that it creates a market for offset projects, of which there are not enough on tap to meet demand from the industrialized countries.

Bottom line: any meaningful deal out of Copenhagen needs to set out real reductions from the countries who have done the most to cause the problem.

Topics: Climate change & energy policy, Environment, resources & sustainability