Carbon dioxide emissions saw a sharp increase between 2015 and 2016, according to the annual Greenhouse Gas Bulletin released by the World Meteorological Organization (WMO).
In 2016, average concentrations of CO2 hit 403.3 parts per million, a jump from 400 ppm in 2015. And these numbers measure what's left in the atmosphere after various "sinks," like the oceans and forests, have absorbed significant amounts of CO2.
We haven't seen CO2 levels like this for 800,000 years.
"It is the largest increase we have ever seen in the 30 years we have had this network," Oksana Tarasova, chief of WMO's global atmosphere watch program said to BBC News.
In addition to the cumulative release of CO2 emissions, the 2016 El Niño played a sizable role in the increase of CO2 concentration in the atmosphere. The weather phenomenon was responsible for droughts that limited the ability of the Earth to absorb CO2 over the course of the year.
"Without rapid cuts in CO2 and other greenhouse gas emissions, we will be heading for dangerous temperature increases by the end of this century, well above the target set by the Paris climate change agreement," WMO Secretary-General Petteri Taalas said in a statement. "Future generations will inherit a much more inhospitable planet."
The WMO's report and the United Nation's own Emissions Gap Report, which will be released on Oct. 31, are likely to play a sizable role in the upcoming UN climate negotiations slated to begin on Nov. 7 in Bonn, Germany.