The first wave of Keystone XL Pipeline protests — the arrests at the White House back in August — was one for the history books. At a time of crisis in the climate movement, and in the Obama presidency, the protesters managed to open a major new front in the carbon war and even to invigorate the domestic climate movement. Moreover, there’s every reason to hope that the resistance to the pipeline will keep rising. Still, a friend of mine recently asked me: “Why oppose this project and why now? Why is this an important line in the sand?”

It’s a fair question. And here’s my answer: Right now, as it becomes obvious that the supply of conventional oil is not infinite (see, for example, here, and here), the future of energy is coming into play in a new way. And so it’s absolutely imperative to prevent the better possibilities from being closed down by a junkie energy policy that doubles down on fossils by targeting high-carbon, “unconventional” dregs like Canadian bitumen. In fact, allowing major investments in fossil-dregs infrastructure would be catastrophic, and this even in a world of catastrophes.

Others have done rollups of the arguments against XL. See, for example, this quick briefing. But I’m going to skip right over the politics, the economics, and all the other local color and head straight for the tar-sands/climate-catastrophe math. I’ll try to get it clear because, while lots of us have heard that Jim Hansen says it’s “game over” if the carbon in the unconventional Canadian fossil fuels is liberated, few of us know exactly what he means.

Here goes:

The key concept is that of a “carbon budget.” This is the total amount of carbon that can be dumped into the atmosphere if we want to keep total planetary warming within “manageable” limits. Now, obviously, there’s no agreement on how large this budget it, but there doesn’t have to be. Leave aside the deniers and focus on the short term — the 2010 to 2050 period that will lock-in the planet’s future climate — and all the reasonable numbers are extremely small.

Let’s follow a key scientific paper. It’s entitled Greenhouse-gas emission targets for limiting global warming to 2°C (it’s behind a pay-wall on Nature, but you can download it here) and was written by a team led by Malte Meinshausen at the Potsdam Institute for Climate Impact Research, which is behind much of the best work on emissions trajectories.

This is not simple material, but one good way of stating the bottom line is that if we want halfway decent odds (80%) of not overshooting a global 2°C temperature target, then we should try to hold total global 2000-2050 emissions down to 886 Gigatonnes of carbon dioxide (CO2). If, like many of the Keystone XL protesters, you prefer the stricter goal of atmospheric stabilization at 350 parts per million of C02, your budget would be even smaller, though not by much.

The problem is that much of this 886 Gigatonnes budget has already been wasted. As of a few months ago, all the nations of the globe had pumped up the post-2000 global emissions by about 321 Gigatonnes, which left us with a remaining budget of 565 Gigatonnes. At the current rate of emissions, that amount is going to vanish into the air long before 2050.

Next, consult the excellent Carbon Bubble report, which hasn’t gotten even a shade of the attention that it deserves. Its authors calculate that:

“The total carbon potential of the Earth’s known fossil fuel reserves comes to 2795 GtCO2. 65% of this is from coal, with oil providing 22% and gas 13%. This means that governments and global markets are currently treating as assets, reserves equivalent to nearly 5 times the carbon budget for the next 40 years.”

Which is why “peak oil” is a bad name for our problem. Because there is no way, in any positive or at least soft-landing storyline, that we’re going to be able to burn the bulk of even the conventional fossil fuels that we are already proven, let alone the ones that are still being discovered and otherwise rendered accessible, let alone the “unconventional” fossil fuels in the North American tar sands.

Note that the Carbon Bubble report excludes unconventional oil:

“The figure for unconventional oil is artificially low, we believe, due to Canadian accounting practices which result in oil sands reserves not being booked upon discovery. Instead, they are only reported under Canadian rules once production is believed to be ‘imminent’.”

Fortunately, it’s possible to estimate the amount of carbon in the tar sands. It’s not easy, for a variety of reasons that only energy geeks really need to care about, but it’s possible. Here, for example, is a nice tidy summary from Scraping the bottom of the barrel, a 2008 report from the World Wildlife Fund:

“In terms of the quantity of oil potentially available, ultimate Canadian oil sand reserves are thought to be in the region of 1.7 trillion barrels, with 315 billion probable barrels accessible using technology currently under development. US oil shale deposits are estimated at 1.5 trillion barrels of reserves. There are currently only estimates as to what proportion may be recoverable, but the figure used by the US government is 800 billion barrels.”

And here’s Jim Hansen’s take, from a little piece called The White House and the Tar Sands, which includes a nice graphic representation of the problem.

Hansen writes: “Figure 1 helps make clear why the tar sands and other unconventional fossil fuels are important. The purple bars show the total emissions to date from the conventional fossil fuels (oil, gas, and coal). These past emissions, plus a smaller contribution from net deforestation, are the cause of the CO2 increase from 280 to 391 ppm. The blue bar is 50% of known unconventional fossil fuel (UFF) resources. Supporters of UFF development argue that only 15% of the tar sands resource is economically extractable, thus we may exaggerate their threat. On the contrary, Figure 1 is a conservative estimate of potential emissions from tar sands because: (1) the economically extractable amount grows with technology development and oil price, (2) the total tar sands resource is larger than the known resource, possibly much larger, (3) extraction of tar sands oil uses conventional oil and gas, which will show up as additions to the purple bars in Figure 1, (4) development of tar sands will destroy overlying forest and prairie ecology, emitting biospheric CO2 to the atmosphere.”

So let’s do the math.

Photo courtesy tarsandsaction NASA Scientist James Hansen being arrested for
protesting in front of the White House on August 29.

First of all, let’s assume that we don’t burn any of the unconventional fossil fuels that are on the US side of the border, because, after all, we’re not that stupid. So we’re just talking about the Canadian reserves, the ones that might be headed down the Keystone XL pipeline. Each barrel of oil-sands crude contains about .88 tonnes of CO2 (this is WWF’s number; it’s rough, but let’s use it anyway), so if we take just the Canadian reserves (315 billion probable barrels) that comes to 277 Gigatonnes of carbon dioxide. If we instead take total North American reserves, the damage comes to 980 Gigatonnes of CO2. That would blow the entire “safe” global carbon budget, all by itself. As if we weren’t well on the way to doing it anyway. Which is to say that, as Hansen put it a few years back, “squeezing oil from shale mountains is not an option that would allow our planet and its inhabitants to survive.”

It’s now time to be even blunter.

The battle to stop the Keystone XL pipeline offers us a chance to draw a defensible line in the sand. Which is not to say that it’s going to be easy to win. As destructive as unconventional fossils are, the game is set up to make them profitable, and this is unlikely to change in the near future. In fact, it’s unlikely to change at all, except in the context of a much broader, more than merely “environmental,” shift against self-dealing elites and in favor of the real interests of ordinary people. In the meanwhile, we have to fight this fight, and we have to fight to win, because developing the unconventional fossil resource means investing in continued fossil lock-in. Further development of the tar sands (which is what Keystone XL is all about) represents a recklessly stupid energy policy that speaks extremely ill of its advocates. It more or less amounts to a choice of blindness and a refusal of legitimate hope. It must not be allowed to happen.

If we really want to stabilize the climate system, then we can’t even burn the majority of the conventional carbon that the fossil companies are already carrying on their books. Not even close. Which goes a long way towards explaining why the term “climate emergency” isn’t a hyperbolic one. An emergency is something you may choose to ignore, but only at your peril. This one, in particular, has all sorts of cascading implications. The technology wars (over nuclear power and carbon sequestration) are part of the story, as is the fact that peak oil isn’t going to save us. We’re going to have to save ourselves, and we’re going to have to do so while we leave the oil in the soil.

The math doesn’t show any other result.