Countries worldwide have massive oil, natural gas, and coal reserves that they could tap. But much of those reserves must remain unused in order to keep global warming under 2 degrees through the end of the century — an important tipping point, according to scientists.
A new study published in Nature
breaks down the reserves by country, and lays out how much each nation has to leave underground to stay within the temperature target. It says that globally, one-third of remaining oil reserves, half of the natural gas reserves, and over 80 percent of coal reserves must remain unused in order to stay within that threshold. It says that any development of Arctic fossil fuel reserves or additional unconventional oil production — think offshore drilling and fracking in shale formations — also works against that goal.
"Our results show that policy makers' instincts to exploit rapidly and completely their territorial fossil fuels are, in aggregate, inconsistent with their commitments to this temperature limit," the study's summary says.
The United States is experiencing a domestic oil and gas boom, and in 2014 it was likely the world's leading oil producer
. But to do its part to limit global warming, the US must leave untapped 9 percent of its oil reserves, 6 percent of its gas reserves, and 95 percent of its coal reserves.
Other regions would have to leave substantially more of their reserves in the ground. The Middle East, for example, would have to refrain from extracting 38 percent of its oil reserves, 61 percent of its gas reserves, and almost all of its remaining coal.
And the report recommends keeping approximately three-quarters of Canada's crude oil supply — much of which is in the country's tar sands — in the ground. Opponents of the Keystone XL pipeline say that the study provides another reason why President Barack Obama should reject the tar sands pipeline; earlier this week, Obama's press secretary said that the president would veto
any legislation from Congress approving the pipeline.