How much carbon can we safely store underground? Much less than previously thought.

Drawing down carbon from the air and stashing it in underground rock formations has been framed as an essential way to slow and reverse global warming. But new research published Wednesday in the journal Nature finds there are far fewer suitable places to do this than previously thought.

After screening out “risky” areas, like those that are vulnerable to earthquakes, a team of researchers from Europe and the U.S. found that the Earth can only safely store about 1,460 gigatons of injected carbon in its sedimentary basins. This is an order of magnitude less than previous estimates, and — if you convert stored carbon to an estimated impact on the climate — only enough to cut global warming by about 0.7 degrees Celsius (1.3 degrees Fahrenheit), not the 6 degrees C (10.8 degrees F) described