The concentration of greenhouse gases in the atmosphere continues to skyrocket: levels of CO2, methane and nitrogen oxide in 2023 have marked a new maximum, condemning the planet to “many years of increase temperatures”, according to the latest Bulletin of the World Meteorological Organization (WMO).
In 2023, high emissions from the burning of fossil fuels, huge forest fires (a consequence of climate change) and a possible reduction in carbon absorption by forests (saturated by the capture of CO2 released by activities human) were combined, so that the level was achieved. of this gas reached 420 parts per million (ppm) as an annual average.
These levels represent uncharted territory for humans, as the last time the planet recorded a comparable concentration of CO2 was between three and five million years ago. In this context, the global temperature of the planet was between 2°C and 3°C higher and the sea level between 10 and 20 meters higher than today.
In addition to carbon dioxide, the dome of gas that traps the heat of the Sun and retains it on Earth is mainly supplemented by methane and nitrous oxide (N2O). Both marked historic highs last year, according to WMO data. The level of methane (CH4) is already 265% higher than in pre-industrial times (1750) and nitrous oxide is 125%.
This increasingly dense dome, or gaseous crust, traps solar radiation that should escape into space after bouncing back to Earth. This trapped radiation (heat) increases the global temperature of the planet and modifies the climate. This is where the effects of the climate crisis are triggered.
Another year, another record. This should set off all alarm bells among decision-making bodies. There is no doubt that we are very far from reaching the goal of the Paris Agreement.
Celeste Saulo
— WMO Secretary-General
The speed at which the greenhouse layer is thickening is unprecedented. Over the past 20 years, CO2 concentration has increased by 11%. “The accumulation has never been so rapid in the history of humanity,” specifies the Bulletin.
“Another year, another record. This should set off all alarm bells among decision-making bodies. There is no doubt that we are very far from achieving the Paris Agreement target,” says WMO Secretary-General Celeste Saulo.
Because as long as emissions continue, greenhouse gases will continue to build up in the atmosphere, which will undoubtedly lead to an increase in global temperatures. At current levels, rising temperatures will persist for decades because CO2 remains in the atmosphere for “extremely long periods.”
Moreover, as gases linked to the current production and consumption system continue to be pumped out, “we run the risk of being trapped in a vicious circle: climate change itself could transform ecosystems into important sources of greenhouse gases instead of sinks,” explains the organization’s deputy. secretary, Ko Barrett.
Data so far indicates that just under half of CO2 emissions remain in the atmosphere, the ocean absorbs just over a quarter, and terrestrial ecosystems absorb just under 30%. The vicious circle that Barret warns against would change this balance.
National climate plans are not enough
However, while there are few dates left for the start of the Climate Summit (COP29) in Azerbaijan, the review of the climate plans presented by the countries (the NDCs) carried out by the UN indicates that, all together, they would be able to to reduce their emissions in 2030 will only be 2.6% compared to 2019 levels. In other words: they are missing 43% if they intend to comply with the Paris Agreement.
States are preparing new plans to present next year. Thus, the analysis insists, so far “there is only marginal progress compared to last year. “A fraction of what is expected and urgently needed. »
“Current national plans fall far short of what is needed to stop global warming. The progress made so far is very small compared to what is expected to be achieved next year,” said the executive secretary of the United Nations Climate Change Convention, Simon Stiell.
