Greenhouse gas levels in atmosphere ‘reach new record highs’

Levels of greenhouse gases in the atmosphere have reached another record high, the World Meteorological Organisation has warned.

Concentrations of carbon dioxide, the main gas driving global warming, reached new highs of 407.8 parts per million in 2018, up from 405.5 parts per million (ppm) in 2017, a report by the UN body shows.

That is well above the level of around 280 ppm seen before the industrial revolution and the start of large scale burning of fossil fuels for energy and transport, which have driven up carbon dioxide in the atmosphere.

The rise is close to the increase seen between 2016 and 2017 and just above the annual average over the last decade, continuing of a long term trend set to drive increasingly severe impacts of climate change, the WMO said.

Concentrations of other climate-warming greenhouse gases methane and nitrous oxide also surged by higher amounts in 2018 than in the past decade, the observations from the global atmosphere watch network show.

WMO secretary-general Petteri Taalas said: “There is no sign of a slowdown, let alone a decline, in greenhouse gases concentration in the atmosphere despite all the commitments under the Paris Agreement on Climate Change.

“We need to translate the commitments into action and increase the level of ambition for the sake of the future welfare of the mankind,” he said.

He said the last time Earth experienced comparable concentrations of carbon dioxide in the atmosphere was three to five million years ago, when temperatures were 2C to 3C warmer and sea levels were 10-20 metres higher than today.

Human activity is creating greenhouse gas emissions, which are driving up the concentrations of the gases such as carbon dioxide in the atmosphere, where they have a warming effect on the Earth’s climate.

This global warming is driving impacts such as melting glaciers and sea level rise, more extreme droughts, heatwaves and storms and posing a threat to food security, water supplies and wildlife.

But the WMO warns that even with the pledges made by countries under the international Paris deal, global emissions are not estimated to peak by 2030, let alone by the 2020 date that scientists have said is necessary to curb dangerous climate change.

Preliminary findings for 2018 suggest greenhouse gas emissions continued to rise last year.