On the potential for oilsands to add 200ppm of CO2 to the atmosphere

Over the last few days, posts by Bill McKibben in the Guardian and by NASA scientist Dr. James Hansen on his own website at Columbia have again brought forward the statistic that, “the tar sands are estimated to contain at least 400 GtC (equivalent to about 200 ppm CO2).”  That’s true but, in the context of building the Keystone XL pipeline, the statistic is laughably out of context.

The Keystone XL pipeline, if approved, will transport about 700,000 barrels per day (bpd) (although some have cited figures as high as 800,00 bpd) of mostly, but not exclusively, oilsands product to the US Gulf Coast. Let’s use NRDC figures for the impacts, so you know I am not sandbagging the numbers.  At 112.2 kg CO2/MMbtu on a wells-to-wheels basis, Canadian oilsands-sourced gasoline has life-cycle emissions of about .616t/bbl.  Figures will be lower or higher depending on the resource base, the extraction technique, etc., but I’ll use this as a benchmark.

That benchmark means that the Keystone XL pipeline will transport enough product in a year that, as it is extracted, refined, and burned in your cars, it will produce about 157 Mt/yr.  There’s no question that’s a big number for a single project.  In fact, those emissions are equivalent to those of all the cars and trucks on the road in Canada.  Coincidentally, it’s almost exactly equivalent to the emissions which will flow from all the NEW coal fired power plants currently under construction or development in the US, but just for the power they produce…not counting the full life cycle. But, that really isn’t the point.

The point is that these posts by both Hansen and McKibben suggest that the Keystone XL pipeline should be judged against the carbon contained in almost every bitumen molecule (the original oil in place of 1.7 trillion barrels) in Northern Alberta. That’s right.  To get 200 ppm, or 400 GtC of carbon, or 1468 GtCO2, you would have to extract, refine, and burn about 2.4 trillion barrels of oil using today’s technology.  Now, extraction technology may improve, but those un-economic barrels will be hard to get, so let’s assume that today’s life cycle emissions per bbl remain constant over time.  To get that many barrels out of the ground, at 5 million barrels per day, would take you until the year 3316.  If we replaced all of today’s global oil production with oilsands product, it would take 80 years to produce 2.4 trillion barrels.

There’s another assumption in the objections put forward by Mr. McKibben and Dr. Hansen – that the oil not produced from oilsands would not be replaced.  Let’s make a conservative assumption that it gets replaced by the lowest emission barrel in the NRDC report, US domestic crude. If this were true, then the annual incremental emissions saved by cancelling the Keystone XL pipeline would be about 28 Mt CO2/yr, or .0078 GTC/yr.

Let’s be generous and assume that the Keystone XL pipeline, if built, remains in service for 100 years, and the gap between oilsands crude and US domestic production remains constant. Over the life of the pipeline, the incremental impact on global atmospheric carbon would be about .78 GtC.  If you assume that the displaced production would be replaced entirely by emissions-free energy sources, then you get a lifetime impact of cancelling the project of 4.27 GtC. In short, Hansen’s argument about the 200ppm impact of oilsands on GHG emissions would hold if we were talking about building 95 Keystone XL pipelines. Then again, who knows, perhaps oilsands-sourced liquid transportation fuels will be replaced by coal-to-liquids….now wouldn’t that just be a big win in the climate fight.  Without a broad GHG policy in place, there is no reason to expect that oilsands products would not be replaced with even higher emissions sources of oil.

In the fight against climate change, every bit counts, but to make an argument that is based on a leverage ratio of somewhere between 90 and 500 times the actual damage caused by a particular project is not the right way to go about it.  Perhaps Mr McKibben’s role is to act on a project by project basis, but I would expect both he and Dr. Hansen to see the big picture – if you want deep cuts to GHG emissions, you need a broad-based policy, not a hopelessly leveraged argument against a single project. In my opinion, those are the arguments most likely to be ignored as alarmist.