The amount of carbon dioxide in the atmosphere reached its highest level in 800,000 years in 2016, the World Meteorological Organization (WMO) said Monday.
Carbon dioxide levels "surged" at record breaking speeds last year, with globally averaged concentrations of CO2 hitting 403.3 parts per million in 2016 compared to 400 parts per million in 2015, according to the WMO's Greenhouse Gas Bulletin.
This was due to a combination of human activities and a "strong" El Nino event, the report said. El Nino and La Nina refer to the "warm and cool phases of a recurring climate pattern across the tropical Pacific," according to the National Oceanic and Atmospheric Administration.
The WMO said that direct measurements from the past 800,000 years had been taken using both Antarctic ice cores and "modern instruments."
The increase in concentrations of greenhouse gases in the atmosphere commenced in the industrial age, which began in 1750. This was down to a range of factors including population growth, as well as industrialization and its use of fossil fuel sources.
"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," Petteri Taalas, the WMO's secretary-general, said in a statement. "Future generations will inherit a much more inhospitable planet."
Under the Paris Agreement, reached at the end of 2015, world leaders committed to making sure global warming stays "well below" two degrees Celsius above pre-industrial levels, and to pursue efforts to limit the temperature rise to 1.5 degrees Celsius.
At the beginning of June, however, President Donald Trump announced that the U.S would withdraw from the Paris Agreement and commence talks to re-enter or negotiate a new accord.
Taalas said that CO2 remained in the atmosphere for hundreds of years and in 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."
Erik Solheim, the head of UN Environment, said that while the last few years had seen an enormous uptake in renewable energy, a redoubling of efforts was needed "to ensure these new low-carbon technologies are able to thrive. We have many of the solutions already to address this challenge. What we need now is global political will and a new sense of urgency."
The WMO's bulletin was based on analysis from the WMO Global Atmosphere Watch program.