To Curb Global Warming, 90 Percent of U.S. Coal Should Stay Buried

If nations want even a 50 percent chance of avoiding dangerous global warming, they’ll need to keep more than 80 percent of current coal reserves in the ground. And in the United States, more than 90 percent of coal reserves would need to stay buried, according to a new study from University College London.

The study is the latest effort by researchers to put numbers on just how much coal, oil, and gas humanity can safely burn without committing the planet to temperature increases above the 3.6 degree Fahrenheit (2 degrees Celsius) goal agreed on by international negotiators. Previously, scientists have estimated that the amount of current fossil fuel reserves exceed what we can burn by about a factor of three. In this new paper, published Wednesday by the journal Nature, researchers tighten the focus of this global carbon budget by breaking the global numbers into regional ones.