Different perspectives on GHG emissions

When emissions are reported for the US or Canada, there is an accounting convention that restricts the total to emissions released within the borders of that jurisdiction. This means that Canada’s exports of tar sands oil are counted only to the extent that fossil fuels are used in the extraction and processing, not the combustion of the final product in the US.

In BC, this came up in a recent approval of a new natural gas processing facility in the northeast, which will add more than 2 megatonnes per year to BC’s GHG inventory, but another 16 Mt per year downstream when it is eventually combusted (see this post). If we counted those emissions (and other emissions associated with the extraction phase) it would make BC’s total emissions inventory about one-third higher. To put that in perspective, BC’s much-lauded carbon tax is only estimated to reduce emissions by 3 Mt per year after 2020 relative to business-as-usual growth.

A new study by Davis and Caldeira takes a consumption or lifecycle approach to emissions to see how much has been “outsourced” to countries like China who make the stuff we consume:

Over a third of the carbon dioxide emissions linked to good and services consumed in many European countries actually occurred elsewhere, the researchers found. In Switzerland and several other small countries, outsourced emissions exceeded the amount of carbon dioxide emitted within national borders.

The United States is both a major importer and a major exporter of emissions embodied in trade. The net result is that the U.S. outsources about 11% of total consumption-based emissions, primarily to the developing world.

The full study has to be purchased through the publisher (here), but a good (free) summary of the main findings is here.

Canada, according to the study, is a small net exporter of GHG emissions. No data for Canada are presented, unfortunately, as Canada does not crack the top 10 net exporters list. But there is some work from Statistics Canada from a few years ago that sheds some light on this. A study by Joe St. Lawrence found that in 2002 Canada exported 264 Mt of Co2 equivalent emissions, an amount that is about half of total GHGs produced domestically. In the same year, about 105 Mt of GHGs were attributable to Canadian consumption as embodied in imported goods. This means net GHG exports were 151 Mt, a figure that is hardly “small” – enough to be number five on the Davis and Caldeira list (differing methodologies make these incomparable).

These studies are useful in highlighting the challenges of developing a new framework for GHG mitigation on the world stage. Exemplary countries that appear to be making progress on the emissions front, like many in Europe, may in fact be better at outsourcing the emissions associated with their consumption. That said, Canada still ranks number five in consumption-related emissions, at 16.6 tonnes per person in 2004. Australia is slightly ahead (16.7) followed by Singapore (20.2), the US (22.0) and Luxembourg (34.7).

Another complexity is to look beyond just annual emissions. A deal-breaker issue in Copenhagen was the historical responsibility for GHG emissions, the fact that the advanced countries have been using the global commons “sink” to spur their economic growth for much longer than developing countries, who are now being asked to make similar reductions. I recommend a lecture Naomi Klein gave recently to a CCPA gala on the topic of climate debt, where she argues that emission reductions in rich countries are fundamentally a matter of justice from the perspective of poorer countries.

To give a sense of the magnitudes of historical emissions, the World Resources Institute has data on historical emissions (in this case, via the Guardian’s awesome data blog). The number one historical emitter, by far, is the US, with almost 30% of total emissions going back to 1900. Russia and China are next, each with just over 8% of the historical total. Canada ranks ninth, with responsibility for just over 2% of the total (a number consistent with is annual contribution).

If we were take the top 15 historical emitters (in descending order: US, Russia, China, Germany, UK, Japan, France, India, Canada, Ukraine, Poland, Italy, South Africa, Australia and Mexico), these countries account for 80% of total historical emissions. It makes for an interesting list because it is not exclusively rich countries. Part of this is due to population size: if we group the Western European countries together, they total more than 11% of the total.

It would be interesting to lump these two broad issues together: historical consumption-related emissions. For example, historical emissions show that China’s claim to be just another developing country that needs leeway to grow its emissions is a sham, but on the other hand the Davis and Caldeira study finds that China is also the number one net exporter of emissions by a large margin, with 22.5% of its annual emissions dedicated to exports (this number may be even higher now, as the study data is for 2004).

Finally, this all highlights the need to account for trade flows in accounting and in policy responses. Domestic policies to reduce emissions may be ostensibly successful, but may only encourage the outsourcing of emissions, with little change from a consumption perspective (or worse, larger emissions if Chinese power is from coal and production practices are more inefficient). Carbon tariffs, for example, would have to be considered alongside any carbon tax to level the playing field.


  • Of course, I endorse your policy conclusion regarding carbon tariffs. However, this post includes two antithetical conceptions of lifecycle emissions.

    The first couple of paragraphs seem to advocate counting them against the producing country. You suggest adding emissions from burning Canadian fossil fuels in other countries to Canada’s national emissions.

    However, Davis and Caldeira argue for counting lifecycle emissions against the consuming country. They would add the emissions from extracting fossil fuels in Canada to the national emissions of countries that burn those fuels.

    The current convention falls between these two concepts by simply counting emissions where they occur, regardless of the original producer or ultimate consumer.

  • My main point was that there are different ways of looking at GHG emissions, and lifecycle approaches offer us some insight into the cross-border nature of emissions in a globalized world. In the case of BC, the point is to acknowledge the responsibility we have as importing consumers, or as producing exporters, for the emissions that are counted in someone else’s inventory.

  • One point that further expands on these thoughts- at least I think so.

    As we move forward in our understanding of GHG emissions, new feedback mechanisms and loops are being discovered, that will have a significant downstream chemical impact on GHG emissions.

    Say for example much of the dispursement of non-GHG particulate is in some cases accelerating the formation of GHG’s within different layerings of the atmosphere that effect the size of the windows with which GHG can escape and hence creating a cascading mutlilevel effect on reflection of photon. These of course are only now being discovered, and the research on cloud formation and particulate containment comes from various man made sources.

    Similar to CFC’s which were manmade we yet discover that new compounds appear and thus have an historical legacy.

    This mean we may have to a dynamic set of figures, when determining the carbon deficit.

    Another example-

    In Canada, when we lose more and more of our snow cover due to warming, we will be contributing more to the heating due to less reflection, which in turn also unlocks more methane that was frozen within the tundra.

    So the point being, I am very leary of these quantifications. And that is exactly what cost the climate change movement a lot of social capital in the fiasco in the UK. And hey- as I said before I am not anti-academic or anti-scientific, I just want us to all undertand that we are at the beginning of a movement, and we must be careful with how we work these measurement tools, lest we get nailed at the stake again by the deniers.

    All the meetings, and all the thoughts, and all the hard work by passionate people was put on the stake and burned by the deniers and their witch hunt on the UK. And the negative media, generated destroyed so much.

    I think a different approach must be taken that this whole taking big leaps with such detailed quantification. We need some general numbers that are robust and more of the qualitative/ quasi quantitative carbon deficit numbers.

    Sorry but I think this is going in the wrong direction.


    However, given the fact that the public’s mind must be won over,

  • sorry that should be the photons escaping not the ghg

  • Hi Marc – I was wondering why you chose 1990 as a base year to measure historical emissions? The total amount of C02-eq concentration that the atmosphere can sustain without intiating dangerous climate change is a set figure – thus a more useful starting point would perhaps be 1850 or the beginning of significant C02-eq emissions? I think that Naomi Klein is using this as her reference when she talks of historical emissions and climate debt. I’m sure the different starting date would create a very different list of top of who is responsible for 80% of emissions (or at the very list the developed world’s share).

  • Alex: You’re right: it is a better to have more years when counting historical emissions, particularly for the US, UK and Germany as early industrial countries. I do have a dataset going back to 1850 but I could not find the original online, so I linked to, and used, the 1900-2004 source instead.

    The 1850 data is also WRI via the Guardian (shared by google spreadsheets), but was appended as an extra tab in a file for World Carbon Dioxide Emissions, 1980-2006 if anyone wants to to track down the original.

    The grand totals and country shares do not change very much though. Between 1850 and 1900, the world total emissions were about 37 Gt, which compared to 29 Gt in 2006 alone! And total world emissions from 1850 to 2004, were 1,102 Gt.

  • I beg to differ on the philosophie behind the accounting.

    I actually it is right to consider that goods that will generate further GHG emissions (such as gas and oil) destined to exports should be accounted in the importing country’s emission. Although I do agree that I feel somewhat uneasy about this in some way (well, I only gave him the loaded gun, he’s the one who pulled the trigger), I think that should be we make progress towards any kind of cap and trade system, this will be better, because then the incentive is on the manufacturer who will be using this oil and gas to lower its emission, whereas if they are accounted in the country where they are extracted, then where’s the incentive to lower emission for the end user?

Leave a Reply

Your email address will not be published. Required fields are marked *