Humans will have to not only stop emitting greenhouse gases by 2085, but also develop technology that will result in negative emissions — the removal of 15 billion tons of carbon dioxide from the atmosphere each year by the end of the century — in order to prevent global warming from exceeding 2 degrees C (3.6 degrees F), according to a new study.

Human greenhouse gas emissions, including methane and carbon dioxide, have already warmed the globe more than 1 degree C (1.8 degrees F) compared to pre-industrial levels. The Paris Climate Agreement negotiated last year seeks to cap warming to below 2 degrees C, while at the same time pursuing an even more ambitious goal of limiting warming to 1.5 degrees C.

But according to a new National Center for Atmospheric Research study, just cutting emissions under the Paris agreement may not be enough to keep global warming from blasting past 2 degrees C, said Benjamin Sanderson, the study’s lead author.