To achieve the goals of the Paris Agreement, countries will likely need to set hard limits on the extraction of fossil fuels in addition to supporting the deployment of clean energy. That’s one of the key takeaways of a new study published in the journal Nature on Wednesday by energy and climate modelers from University College London.

The researchers set out to estimate how much of the world’s fossil fuel reserves must remain in the ground in order to limit global warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) above preindustrial temperatures — the target named in the Paris Agreement that would prevent the most catastrophic impacts of climate change. They found that in order to have a 50 percent chance of achieving this target, 58 percent of known oil reserves, 59 percent of natural gas reserves, and 89 percent of coal reserves cannot be extracted. This means that global oil and gas production must decline 3 percent on average every year until 2050.

“I think there’s an increasing recognition that policy measures and action targeted at production itself is going to be needed to get the kind of decline rates that we’re thinking about here,” said Steve Pye, one of the study’s authors, during a press call on Tuesday.

In their presentation to reporters, the authors stressed that these numbers are likely an underestimate of the scale and speed of fossil fuel production cuts required for two reasons. The first has to do with the carbon budget — the amount of carbon that can be emitted before the planet warms more than 1.5 degrees C. Because of the uncertainty built into climate modeling, there is no universally agreed upon carbon budget, but rather a range that scientists estimate will give us a better or worse chance of achieving temperature targets. The paper uses a carbon budget of 580 billion metric tons, an amount that is estimated to give only a 50 percent chance of stabilizing the global climate at 1.5 degrees C above preindustrial temperatures.

Read the full article about fossil fuels remaining buried by Emily Pontecorvo at Grist.