Atmospheric levels of climate-changing greenhouse gases hit a record high in 2018, “with no sign of a slowdown, let alone a decline,” the World Meteorological Organization said.
In a report released Monday, the WMO said despite international pledges made under the Paris Agreement, the levels of carbon monoxide, methane and nitrous oxide all surged by higher amounts in 2018 than average for the past decade.
The global average of carbon dioxide concentration reached 407.8 parts per million in 2018, up from 405.5 parts per million in 2017, the U.N. agency said. The concentration of methane was the highest recorded since 1998 while the levels of nitrous oxide, which is responsible for eroding the ozone layer was the highest ever recorded.
"This continuing long-term trend means that future generations will be confronted with increasingly severe impacts of climate change, including rising temperatures, more extreme weather, water stress, sea level rise and disruption to marine and land ecosystems," according to a summary of the report.
The report was released ahead of next month’s global climate summit in Madrid.
“It is worth recalling that the last time the Earth experienced a comparable concentration of carbon dioxide was 3-5 million years ago," WMO Secretary-General Petteri Taalas said.
At the time, the Earth's temperature was as much as 5 degrees warmer and sea levels were as much as 65 feet higher than they are now, he said.