Two degrees and fairness

The CCPA’s Climate Justice Project released a new technical paper today on what BC’s targets should be in line with some notion of global equity. It is a nice collaboration between Colin Campbell of the Sierra Club of BC and Cliff Stainsby of the BC Government and Service Employees Union. The paper is, I have to admit, on the dense side, full of jargon and numbers, so you have been warned, but for the geekily inclined it is a fascinating read.

Colin and Cliff start from the premise that the science tells us we need to keep global temperature increase to 2 degrees above pre-industrial levels. We are currently at 0.7 to 0.8 degrees, and there is some inertia built in such that even if we stopped emitting carbon dioxide and other greenhouse gases worldwide tomorrow, temperature is going to creep up at least another half-degree. And above 2 degrees (roughly speaking, this is all about probabilities and averages across numerous studies), we risk runaway climate change; in some sense, two degrees becomes six degrees and seven billion humans cohabiting the planet is just not on. So basically, we are running out of wiggle room, fast.

They then worked with Andrew Weaver of the Climate Modelling Lab at the University of Victoria to run a bunch of stabilization scenarios that keep us under 2 degrees, and picked one that requires global GHG emissions fall by 83% by 2050. Given that BC is already above the world average, what is a fair target for BC?

The short answer is 94% by 2050, but it also depends what you mean by fair. The total stock of emissions released over time matters more than targets for any given year because the path we take to the target can vary wildly. One definition of fairness would be to say that everyone on the planet has an equal right to emit GHGs, so between now and 2050, or now and 2100, our share of the total “carbon budget” should be the same as our share of the population. The tricky part is that we are already way above our fair share on an annual basis, so this would mean a rapid crash in emissions followed by an extended period where we were under the global average, all while the annual global “cap” is shrinking.

To me, this purest form of equity is just not on. What is more realistic is that we converge to an annual amount of emissions that is consistent with our population share. We could reach that sooner or later but 2050 is 42 years away, so all the better to focus our attention. If we reduced emissions by 6.6% per year between now and then, we get to parity in per capita emissions on a global basis; thereafter we would have reduce emissions by 4.1% per year, in line with everyone else, to 2100. Then we can kick back, pat ourselves on the back for having averted catastophe and saved humanity, then get back to dealing with the ongoing fallout from the climate change that has already happened. This could still be ugly enough to make Katrina look like a summer thunderstorm, but hey, let’s try and stay upbeat: the good news is there will be lots of work to go around.

Finally, to compensate for the fact that we are over our fair share between now and 2050 (though getting closer with each year), we should pay out to poor nations who are currently under the global sustainable rate to not increase their emissions. Even at a carbon price of $100 per tonne over the 42 years to 2050, this averages out as an an annual cost to the BC Treasury of $1.5 billion per year, no small chunk of change, but equal to about 0.5% of BC’s 2008 GDP. This could also come in the form of technology transfer or support of clean and green power, mobility and energy efficiency projects.

What does this mean for the BC government, which has a legislated target of 80% reduction in emissions by 2050? By Colin and Cliff’s math, and if we care about equity, that target is too low. We are really looking at going mostly carbon neutral by 2050. I’m an optimist here: diffusion of existing technologies would offer a great start; and there is a lot of potential upside from new innovation. But we are also going to have to make some choices – air travel comes to mind.