Concentrations of carbon dioxide in the atmosphere surged at a record breaking speed last year.
New research by the World Meteorological Organisation (WMO) reveals it rose a level not seen in 800,000 years.
It grew to 403 parts per million in 2016 due to a combination of human activities and the El Nino weather event – an intermittent event involving a period of warming.
The higher this concentration gets, the greater the greenhouse gas effect becomes.
The WMO suggests rapily increasingly atmospheric levels of CO2 and other greenhouse gases have the potential to initiate “unprecedented changes in climate systems, leading to “severe ecological and economic disruptions”.
Since 1990, there has been a 40% rise in total radiative forcing, i.e. the warming effect on climate, by greenhouse gases and a 2.5% increase from 2015 to 2016 alone.
WMO Secretary-General Petteri Taalas said: “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. Future generations will inherit a much more inhospitable planet.
“CO2 remains in the atmosphere for hundreds of years and in the oceans for even longer. The laws of physics mean that we face a much hotter, more extreme climate in the future. There is currently no magic wand to remove this CO2 from the atmosphere.”