Levels of atmospheric carbon dioxide are predicted to grow at a record pace this year, projected to blow past a symbolic benchmark of 400 parts per million and creating conditions irreversible for any time scale relevant to modern society, according to a new study.

The report was published Monday in the journal Nature Climate Change as a collaboration between the Met Office Hadley Centre for Climate Science and Services in England and UC San Diego’s Scripps Institution of Oceanography, which maintains the world’s longest stretch of measurements for atmospheric concentrations of carbon dioxide.