Skip to Content

Global Carbon Dioxide Levels Just Reached a Dangerous New High—Again

Global carbon dioxide concentrations reached an average of 405.5 parts per million in 2017, a record high since human record-keeping began, the World Meteorological Organization (WMO) reported this week. Methane, nitrous oxide, and even ozone-eating CFC-11 were up, too.

“The science is clear. Without rapid cuts in CO2 and other greenhouse gases, climate change will have increasingly destructive and irreversible impacts on life on Earth,” WMO Secretary-General Petteri Taalas said in a statement. “The last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now.”

“Low-carbon technologies like wind, solar, and electric transport need to become mainstream,” climate scientist Corinne Le Quéré of the University of East Anglia told The Guardian.

That is unlikely to happen fast enough to stop climate change altogether, says energy and environmental scientist Vaclav Smil of the University of Manitoba. “Some of these processes may well see some relatively fast changes in decades ahead, but they will not follow microchip-like exponential rates of improvement,” he writes in IEEE Spectrum Magazine.

This week’s WMO report will be grist for discussion at next month’s Katowice, Poland, meeting to discuss international climate change agreements and rules.