Friday, March 20, 2009

Recent changes in per capita emissions

As we approach the pivotal UN climate meetings in Copenhagen this December, there will be plenty of discussion about the progress, or lack thereof, on greenhouse gas emission reductions among Kyoto signatories. The story is usually told with the graph to the write, compiled from UN Framework Convention on Climate Change (UNFCCC) data. Shown is the change in greenhouse gas emissions (excluding land use change) by country between 1990, the baseline year for Kyoto, and 2006. The emissions are expressed as CO2-“equivalent”, an easy catch-all in which the totals for non-CO2 greenhouse gases like methane are converted into equivalent amounts of CO2. {click on the chart for a better look}

It is no secret at this point that the US and China are the largest emitters of greenhouse gases. China is thought to have matched or surpassed the US in total GHG emission in the past couple years. The comparison, of course, is unfair because there are four times as many people in China. A more equitable metric – per capita emissions – finds that the average American, Canadian and Australian is responsible for more than four times the GHG emissions of the average Chinese citizen.

The importance of describing GHG emissions per capita, rather than only total emissions by country, appears to be widely appreciated at this stage [although one might argue not widely enough, given some of the pre-Copenhagen rhetoric out there in the ether]. However, most of the cursory analyses and discussion of recent trends in GHG emissions in the media and online have focused on the total emissions metric. A lot of Canadians can repeat the statistics on emissions growth, and the difference between current emissions and the Kyoto target. But how have per capita emissions changed? {Continued after the jump}

Here’s one reason this matters. Upon first glance at the total emissions number, European nations appear to have been far more successful at controlling GHG emissions than the rest of the Annex I nations. A common criticism of claims of “progress” in Europe is that most European nations are experiencing very low population growth, even negative growth in the case of some of the former Eastern Bloc nations.

The second chart shows some crude analysis of this question. The chart shows the change in per capita emissions from 1990 to 2005, expressed in CO2-equivalent per capita [this was calculated from the UNFCCC GHG emissions data and population data from the United Nations]. Countries in red experienced an increase in per capita emissions. Another way of thinking about this is that, all else being equal, the change in GHG emissions in these countries is greater than can be explained by population growth alone.

The data illustrates a couple interesting trends. First, the argument that European nations have achieved more progress in slowing or reversing emissions [than the US and Canada] purely because of demographic change is not borne out by the national data in most cases. Of course, a more detailed analysis may find ways in which demographics have played an important role. Per capita emissions decreased in France, Germany, the UK, Sweden, Denmark, the Netherlands, Switzerland, Norway and Belgium, in each case by a greater percent than the total emissions decreased. [for now, I’ll exclude the former eastern Bloc nations from this discussion, since the emissions reduction there were driven more by the collapse of former Soviet industries than the slow or negative population growth].

Second, per capita emissions also declined slight (2%) in the US from 1990 to 2005 [note: no population data was available for 2006]. If Canadians need any more evidence that we and our government have failed miserably at addressing greenhouse gas emissions, as required under the Kyoto Protocol, this is it. Canada’s per capita emissions have risen 6% over a period in which America’s per capita emissions have dropped by 2%. No doubt, the addition of 4.6 million people to Canada between 1990 and 2005 has influenced GHG emissions. However, the country’s total GHG emissions are still 6% higher than could be expected from population growth alone.

It is possible that the economic crisis will change this story – in the Canadian case, the drop in resource and oil prices has slowed industrial activity in the oil sands and other regions, perhaps leading to slower increase, or even a decrease in national GHG emissions.I suspect that all the jumping up and down earlier last year about global GHG emissions being “ahead” of the scenarios used by the IPCC will go for naught, as the economic crisis is surely blunting GHG emissions growth.


John Mashey said...

Do you have, by any chance, the Canada per capita data by province? I've seen USA ones, and of course there's a huge variation, since places like California are ~Europe, and places like Wyoming & Alaska aren't.

Simon D said...

Yes, Alberta and Saskatchewan are by far the largest emitters per capita. There's some information here - - and I'll have more in a future post.

John Mashey said...

Thanks. Useful report. I'm not surprised about Alberta. can you shed any light on why Saskatchewan and Manitoba are as different as they are?