This is a new sad record, which highlights our delay in meeting the objective of the Paris agreement. Levels of the three main greenhouse gases – carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), which contribute to global warming – all increased further in 2023, the Commission announced. World Meteorological Organization (WMO) this Monday, October 28, which will inevitably lead to increases in temperature in the coming years. “Another year. Another record, said WMO Secretary General Celeste Saulo. This should ring alarm bells among policymakers.”
In its annual report on greenhouse gases, published in the run-up to COP29, which will take place from November 11 to 22 in Baku, Azerbaijan, the UN meteorological and climate agency notably warned of the caused CO2 to accumulate faster than ever in the atmosphere, with an increase of more than 10% in two decades.
“These are more than just statistics”
While countries agreed at COP21 to limit global warming to less than 2°C compared to pre-industrial levels, and even to 1.5°C if possible, current climate commitments lead to only 2.6% of drop in global greenhouse gas emissions in 2030 compared to 2019, instead of the 43% recommended to hope to limit global warming to 1.5°C, the UN Climate warned on Monday in another report.
As long as emissions continue, greenhouse gases will continue to accumulate in the atmosphere, increasing temperatures, deplores the WMO, which also points out that global temperatures on land and at sea have been in 2023 «highest ever recorded since 1850. And given the lifespan of CO2 in the atmosphere, current temperature levels will persist for decades, even if emissions decline rapidly to net zero.
By 2023, CO2 concentrations would reach 420 parts per million (ppm), methane concentrations would reach 1,934 parts per billion (ppb), and nitrous oxide concentrations would reach 336 ppb. Or respectively 151%, 265% and 125% more than the levels of 1750 (+1 point in one year for the three gases). “These are more than just statistics. Every part per million and every fraction of a degree of temperature increase has a real impact on our lives and our planet. said Celeste Saulo, quoted in a press release.
“A potential vicious circle”
Concerning CO2, responsible for around 64% of global warming, the increase of 2.3 ppm observed in 2023 is the 12th consecutive annual increase above 2 ppm – due to “historically significant CO2 emissions from fossil fuels in the 2010s and 2020s”, according to the report. The Earth experienced such a concentration of CO2 3 to 5 million years ago, when the temperature was 2 to 3°C higher and the sea level 10 to 20 meters higher than today. , recalls the WMO.
Just under half of CO2 emissions remain in the atmosphere, while the rest is absorbed by ocean and terrestrial ecosystems. But today, “we are faced with a potential vicious circle”, warns WMO Deputy Secretary-General Ko Barret that climate change could soon “causing ecosystems to become greater emitters of greenhouse gases”. Notably, wildfires could release more carbon emissions into the atmosphere, while warmer oceans could absorb less CO2. As a result, she warns, more CO2 could remain in the atmosphere and accelerate global warming.
