Do the oilsands threaten our safe climate? Hansen's "game over" vs Oliver's "minuscule amount"
Famed climate scientist James Hansen wrote an editorial called "Game Over for the Climate" in the New York Times:
Canada’s tar sands … contain twice the amount of carbon dioxide emitted by global oil use in our entire history. If we were to fully exploit this new oil source, and continue to burn our conventional oil, gas and coal supplies … it will be game over for the climate.
Sea levels would rise and destroy coastal cities. Global temperatures would become intolerable. Twenty to 50 percent of the planet’s species would be driven to extinction. Civilization would be at risk … If this sounds apocalyptic, it is … we can’t wait any longer to avoid the worst and be judged immoral by coming generations.
Leading climate activist Bill McKibben explained how Hansen's reasoning plays into the battle to stop the Keystone XL pipeline:
One reason we’re fighting the pipeline is because Jim Hansen did the math to show that if we combusted the tar sands on top of all else we burn, it would be "game over for the climate"
For years, Hansen's central message has been that preserving a stable climate requires both rapidly phasing out coal emissions and leaving unconventional fossil fuels like the oilsands in the ground.
Natural Resources Minister Joe Oliver however wants to rapidly expand the extraction of Alberta's oilsands. He recently lashed out at Hansen and his reasoning saying:
"[Hansen said] if we go ahead with the development of the oil sands it’s “game over for the climate.” Well, this is exaggerated rhetoric. It’s frankly nonsense. I don’t know why he said it, but he should be ashamed of having said it. It’s one-one thousandth of global emissions."
He reiterated this point later to the Huffington Post stating that the Alberta oilsands are:
"one one-thousandth of global emissions ... You're talking about, from a relative perspective, a minuscule amount."
So which is it? "Game over" or "minuscule"?
To help illuminate the answer I'll build a chart in three stages to represent the three key data points:
- Remaining global CO2 budget to avoid dangerous climate changes
- Oliver's argument
- Hansen's argument
STAGE ONE: Remaining safe-CO2 budget
The nations of the world have agreed that "dangerous" climate changes -- causing long term suffering to global civilization -- will be locked in if the planet warms up by more than 2oC. All major nations have agreed to stay below this threshold of danger.
To have a decent shot at staying out of the danger zone the world can only dump another 466 billion tonnes of CO2 (GtCO2) into the atmosphere through 2050. This is the world's remaining safe-CO2 budget for transitioning to a safe, very-low carbon world. After 2050, only relatively small and ever declining amounts of CO2 can be released.
I'll start my chart with a circle representing this global safe-CO2 budget.
For scale I also included a circle representing the CO2 from all the fossil fuels burned so far in Canada (26 GtCO2).
Now let's see how the Alberta oilsands fit in according to Oliver and Hansen.