The World Meteorological Organization (WMO) has released a new report, the Greenhouse Gas Bulletin, and as you might expect the news isn’t great. In 2018, the globally-averaged concentration of carbon dioxide (CO2) in the atmosphere was 407.8 parts per million (ppm), a new record high that hasn’t been seen in millions of years. The report concludes that the window of opportunity to mitigate the effects of climate change is closing fast.

For this new report, the WMO collected data from 53 countries, and crunched it to get an average carbon reading for the whole planet, over the whole year. In 2018, that global average was 407.8 ppm, which is almost 50 percent higher than the pre-industrial level of 280 ppm.

“It is worth recalling that the last time the Earth experienced a comparable concentration of CO2 was 3 to 5 million years ago,” says Petteri Taalas, Secretary-General of WMO. “Back then, the temperature was 2° to 3° C (3.6° to 5.4° F) warmer, sea level was 10 to 20 m (33 to 66 ft) higher than now.”

The 2018 reading also represents a decent step up from the previous year – 2017 recorded a global average of 405.5 ppm. The Bulletin says that the increase from 2017 to 2018 was about the same as that from 2016 to 2017, and was just above average for the last decade.

Unfortunately this growth rate is accelerating over the long term. The report averaged the CO2 growth rate for the past three decades and found a steady increase. Between 1985 and 1995, the average increase was 1.42 ppm per year. Between 1995 and 2005, the increase was up to 1.86 ppm per year, and in 2005 to 2015, CO2 levels were increasing by 2.06 ppm per year. Clearly, this means we haven’t even begun to effectively address the problem.

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

Sadly, it seems we’re full steam ahead to hit further milestones. The threshold of 400 ppm was first crossed as a global average concentration in 2015, and early data suggests that 2019 could be the year this figure crosses 410 ppm. Already, weather stations have reported individual readings of over 415 ppm.

Carbon dioxide isn’t alone up there, either. The Greenhouse Gas Bulletin also shows that emissions of both methane and nitrous oxide are on the rise, too. In 2018, methane reached a new record of 1,869 parts per billion (ppb) – more than 2.5 times higher than pre-industrial levels. The increase from 2017 to 2018 was higher than that of 2016 to 2017, as well as being above average for the decade.

It’s a similar story for nitrous oxide. This ozone-depleting gas hit new highs of 331.1 ppb in 2018, again with a larger increase than the previous year and the decade average.

The report will likely give scientists and policymakers a lot to chew on at the UN Climate Change Conference, set to be held from December 2 to 15.

The Greenhouse Gas Bulletin can be found online at WMO.

Source: WMO