The United Nations weather agency warns of greenhouse gases rising to new highs by 2023
The call comes as global leaders prepare to gather UN climate change conference in Baku next month, amid continued dire warnings about the human cost of ignoring the existential crisis from the United Nations Secretary General António Guterres and others.
Responding to the long-standing call of the United Nations chief, WMO Deputy Secretary General Ko Barrett told journalists that carbon dioxide (CO2) – one of the three main greenhouse gases, along with methane and nitrous oxide – is is now accumulating in the atmosphere “faster than at any time during human existence.” She added that because CO2 lingers in the atmosphere for so long, “we are committed to increasing temperatures for many years to come.”
WMO’s 2024 Greenhouse Gas Bulletin provides a clear scientific reminder that CO2 increases need to slow. According to the WMO Global Atmospheric Monitoring Network, in 2004, the concentration of carbon dioxide in the atmosphere was 377.1 parts per million (ppm), while in 2023 the figure reached 420 ppm. “This is an increase of 42.9 parts per million, or 11.4%, in just 20 years,” Ms. Barrett explained.
WMO Deputy Director emphasized: “This is not just statistics. Every part per million, every part of the temperature increase matters; it matters in terms of glacier and ice retreat rates, increases in sea level rise, ocean temperatures and acidification. It matters in terms of the number of people who will be exposed to extreme heat every year, the extinction of species, the impact on our ecosystems and our economy.”
According to the WMO, significant greenhouse gas-producing events include wildfires and the El Niño weather phenomenon, which will cause drier conditions and “spike” gas concentrations by the end of 2023. The organization’s analysis suggests found just under half of CO2 emissions remain in the atmosphere, just over a quarter are absorbed by the ocean and just under 30% are retained on land.
The important role of wildfires in Canada
WMO senior scientific officer Oksana Tarasova described last year’s wildfires in Canada as “absolutely devastating” in terms of the amount of greenhouse gases produced. Today’s CO2 levels are unprecedented “in human history,” she said. “The last time we saw concentrations of 400 parts per million of CO2 was 3 to 5 million years ago, and during that time, temperatures were 3 to 4 degrees warmer” and sea levels were 10 to 20 meters higher.
The WMO report shows that between 1990 and 2023, radiative forcing – the warming effect on our climate due to greenhouse gases – will increase by 51.5%. CO2 accounts for more than 80% of this increase, according to data from the National Oceanic and Atmospheric Administration’s annual Greenhouse Gas Index.
“As long as emissions continue, greenhouse gases will continue to accumulate in the atmosphere leading to increased global temperatures,” the UN agency said. “Given the extremely long lifetime of CO2 in the atmosphere, the observed temperature levels would persist for several decades even if emissions dropped rapidly to zero.”
When asked whether the UN Climate Conference could yield tangible commitments from countries, the WMO Deputy Secretary-General noted that politicians around the world do refer to the findings. and forecast the latest climate science in their public statements. “So I think they are listening, the question is to what extent will we see that expression at COP29,” she said.
Ms. Barrett noted that measures taken at a national level to move to a “lower fossil fuel economy” are vital to protecting future generations.
“Even though there is a lag and temperatures will increase, we cannot prevent action because there will be variability and a downward trend in temperatures in the future,” she said. It all depends on how quickly we act and how quickly we can reduce those temperatures.”
