The WMO report states that the monthly CO2 average for September at the Mauna Loa reference station in Hawaii was 411.3 ppm, up from 408.5 ppm in September 2019. The same was observed at Cape Grim in Tasmania, Australia, with an increase to 410.8 ppm from 408.6 ppm in 2019.
He said there had been a “growth spurt” in the average level of CO2 for all of 2019, increasing more than the average rate over the past decade. The data shows that measures to reduce emissions are currently far from what is needed to avoid the worst impacts of the climate emergency.
Scientists estimate that emissions must halve by 2030 to give a good chance of limiting global warming to 1.5 ° C, beyond which hundreds of millions of people will face more heat waves, droughts, floods and poverty. Nations pledged to increase their emissions cuts at a UN summit in Glasgow this month, but the meeting was postponed for a year due to Covid-19.
“The drop in emissions from foreclosure is only a tiny part of the long-term graph. We need a continuous flattening of the curve, ”said Petteri Taalas, Secretary General of WMO. “We have crossed the world stage [annual] 400ppm threshold in 2015 and, just four years later, we have crossed 410ppm. Such a rate of increase has never been observed in the history of our archives.
“CO2 stays in the atmosphere for centuries. The last time the Earth experienced a comparable concentration was 3 to 5 meters ago, when the temperature was 2 to 3 ° C higher and the sea level was 10 to 20 meters higher than ‘today. But there was not 7.7 billion [human] inhabitants. ”
The WMO Greenhouse Gas Bulletin, published on Monday, shows that CO2 in the atmosphere is now 50% higher than in 1750, before the industrial revolution. CO2 traps two-thirds of the heat retained on the Earth’s surface by greenhouse gases, and this warming effect has increased by 45% since 1990.
Methane, produced by livestock, rice paddies and the exploitation of fossil fuels, is responsible for 17% of the heat effect. Its concentration is now two and a half times higher than pre-industrial levels. Another important greenhouse gas is nitrous oxide, which comes from the overuse of agricultural fertilizers and the burning of forests. It is now 23% higher than in 1750.
Greenhouse gas data is collected by the Global Atmosphere Watch network, which includes stations in the Arctic, high mountains and tropical islands. These have continued to operate despite Covid-19 restrictions that hamper restocking and staff turnover in often difficult and isolated locations.
Talaas said a “complete transformation of our industrial, energy and transportation systems” was needed. “The changes are economically affordable and technically possible and would only marginally affect our daily life,” he said. “It is welcome that a growing number of countries and companies have made a commitment to carbon neutrality. There’s no time to lose.