Today there was a mass demonstration in Ottawa against the Keystone XL pipeline. The protest in Canada is largely symbolic, as our prime minister has already given the project the go-ahead. But in the US, a similar protest in Washington really does matter, because the decision on whether to allow the project to go ahead will rest squarely with the president.

Others have eloquently explained the issue. I would recommend ClimateSight for a recent overview & background on the protests, and David Pritchard for a sober analysis of the emissions impact.

As I couldn’t make it to Ottawa to make my voice heard, I’ve drafted a letter to Obama. Feel free to suggestion improvements; I plan to send it later this week.

President Obama,

When you were elected as president you spoke eloquently about climate change: “Now is the time to confront this challenge once and for all. Delay is no longer an option. Denial is no longer an acceptable response.” And you repeated your campaign promise to work towards an 80% cut in emissions by 2050. These were fine words, but what about the tough decisions needed to deliver on such a promise?

Sometime in the next few months, you will have to make a decision on whether to allow the Keystone XL pipeline project to go ahead. The pipeline represents a key piece of the infrastructure that will bring onstream one of the largest oil deposits in the world, and a source of liquid fuel that’s somewhere between 15 to 40% worse in terms of carbon emissions per gallon than conventional oil (Pritchard, 2009). The question over whether we will dig up the tar sands and burn them for fuel represents a crucial decision point for the people of the entire planet.

If the pipeline goes ahead, many jobs will be created, and certain companies will make huge profits. On the other hand, if the pipeline does not go ahead, and we decide that instead of investing in extracting the oil sands, we invest instead in clean energy, other companies will make the profits, and other jobs will be created elsewhere. So, despite what many advocates for the pipeline say, this isn’t about jobs and the economy. It’s about what type of energy we choose to use for the next few decades, and which companies get to profit from it.

I’m a professor in Computer Science. My research focusses on climate models and how they are developed, tested, and used. While my background is in software and systems engineering, I specialize in the study of complex systems, and how they can be understood and safely controlled. In my studies of climate models, I’ve been impressed with the diligence and quality of the science that has gone into them, and the care that climate scientists take in checking and rechecking their results, and ensuring they’re not over-interpreted.

I’ve seen many talks by these scientists in which they reluctantly conclude that we’ve transgressed a number of planetary boundaries (Rockstrom 2010). Nobody wants this to be true, but it is. Yet these scientists are continually attacked by people who can’t (or don’t want to) accept this truth. The world is deeply in denial about this, and we’re in desperate need of strong, informed leadership to push us onto a different path. We need an intervention.

The easy part has been done. The science has been assessed and summarized by the IPCC and the national academies. The world’s governments have peered into the future and collectively agreed that a global temperature rise of more than 2°C would be disastrous (Randalls, 2010). It doesn’t sound like much, but it’s enough to take us to a global climate that’s hotter than at any time since humans appeared on the planet.

Now the tough decisions have to be made for how to ensure we don’t exceed such a limit. One of the hardest dilemmas we face is that a significant fraction of the world’s fossil fuel reserves must remain in the ground if we are to stay within the 2°C target. Some recent results from modelling studies allow us to estimate how much of the worlds remaining fossil fuel reserves must remain unexploited (Allen et al, 2009).

Cumulatively, since the dawn of the industrial era, humanity has burnt enough fossil fuels to release about 0.5 trillion tonnes of carbon. Some of this stays in the atmosphere and upsets the earth’s energy balance. Some of it is absorbed by the oceans, making them more acidic. The effect on the climate has been to raise global temperatures by about 0.7°C, with about half as much again owed to us, because the temperature response lags the atmospheric change by many years, and because some of the effect has been masked by other forms of short-lived pollution.

If we want to contain rising global temperatures to stay within the target of no more than 2°C of warming, then humanity cannot burn more than about another 0.5 trillion tonnes. Ever. This isn’t something we can negotiate with the planet on. It isn’t something we can trade off for a little extra economic growth. It is a physical limit. The number is approximate, so we might get away with a little more, but there’s enough uncertainty that we ought to be following good engineering practice and working with some significant safety margins.

Reasonable estimates of the world’s remaining fossil fuel reserves tell us that there is enough to release at least double this amount of carbon. So we have to find a way to leave around half these reserves untapped (Monbiot 2009; Easterbrook 2009). That’s a problem we’ve never solved before: how can we afford to leave such valuable commodities buried under the ground forever?

The only sensible answer is to use that fraction that we can burn as a transition fuel to effect a rapid switch to alternative energy sources. So it’s not so much a question of leaving resources alone, or failing to exploit opportunities for economic development; it’s more a question of choosing to invest differently. Instead of seeking to extract ever more sources of oil and coal, we should be investing in more efficient wind, solar, hydro and geothermal energy, and building the infrastructure to transition to these fuels.

Which brings us to the decision on the Keystone XL pipeline. This pipeline is significant, as it represents a vital piece of the infrastructure that will bring a major additional source of fossil fuels onstream, one that produces far more emissions per unit of energy than conventional oil, and that has the potential, if fully exploited, to double again the emissions from oil reserves. If we decide to build this infrastructure, it will be impossible to pull back – we’re committing the world to burning a whole new source of fossil fuels.

So the Keystone XL pipeline might be one of the most important decisions you ever get to make as president. It will define your legacy. Will this be the moment that you committed us to a path that will make exceeding the 2°C limit inevitable? Or will it be the moment when you draw a line in the sand and began the long struggle to wean us off our oil addiction?

That oil addiction is accidentally changing the planet’s life support system. The crucial question now is can we deliberately and collectively change it back again?

Yours faithfully,

Prof Steve Easterbrook.


  1. Actually, slightly less than perfect, in my opinion. Would add: “Speaking of uncertainty – if weighed evenhandedly, without prejudice to preferred outcomes, and taking our responsibilities seriously, allowances for greater uncertainty could only compel us to work *faster* and consider *more* drastic action.”

    Because those that would lull us into neglecting our responsibility have had all their concrete objections brushed away like flimsy cobwebs, and now they only have appeals to nebulous “uncertainty” to fashion neglect purely out of postponement of moral rational action.

  2. Go Steve, awesome letter.

  3. @Manuel Moe G It’s a good point, but requires quite a bit more text to explain properly. The people arguing about uncertainty have adopted the wrong null hypothesis. I *should* write about this, but I think this letter is already long enough…

  4. Pingback: The Million Letter March | Serendipity

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