On the one hand, COP 28 negotiators are meeting in Dubai, where they are trying to end the first week with progress on the increasingly contested issue of fossil fuels. On the other hand, scientists are warning about the ever more concrete consequences of global warming. And, lately, every day brings its share of bad news, leaving us as if disoriented by an incessant swell. On Tuesday, December 5, scientists from the Global Carbon Project announced that the objective of limiting warming to 1.5°C, decreed with great fanfare by the Paris agreement, was now unattainable. Worse, at the current rate of greenhouse gas emissions, there is a 50% risk that global warming will constantly exceed this symbolic threshold in about… seven years.
Rebelote, Wednesday December 6. Europe’s Copernicus service says 2023 will be the hottest year in history, following an “extraordinary” November which became the sixth consecutive month to break records. And, in the process, a study by Global Tipping Points, published by more than 200 scientists, assures that the Earth is on the verge of crossing five “climate tipping points” and that three more could be reached in the 2030s if the world warms by 1.5 ° C above pre-industrial temperatures. Crossing these tipping points could result in irreversible effects on natural systems crucial to humanity’s livelihood. In other words, behind the hubbub of the COP 28 negotiations, our planet is quietly approaching immeasurable threats.
The concept of a climatic tipping point is now regularly used by scientists to anticipate what humanity will have to face in a very concrete way, beyond simple heatwave episodes or extreme weather events which will multiply. The most immediate danger concerns coral reefs around the world, already heavily impacted by global warming. With an average temperature rise of 1.5°C, or even 2°C very soon, the ice sheets of Greenland and Antarctica are also at risk of irreversible collapse, which could lead to a rise in the level of the sea during this century. With only 1.5°C of warming above pre-industrial levels, northern forests are at risk, as are mangroves and other coastal ecosystems, the report warns. Large parts of the Amazon rainforest could be replaced by savannah with warming of just 2°C, disrupting life across South America and causing even more carbon to be released into the world. atmosphere.
2023 is on track to be the hottest year on record.
© / afp.com/Nalini LEPETIT-CHELLA, Paz PIZARRO
While these global changes will not cause temperatures to spiral out of control in the coming centuries, they will cause considerable damage. “Tipping points in the Earth system pose threats on a scale never before encountered by humanity,” said Tim Lenton, of the Global Systems Institute at the University of Exeter. “They can trigger devastating domino effects, including the loss of entire ecosystems and the ability to grow staple crops, with impacts on humans such as mass population displacements, political instability and financial collapse.” Scientists caution, however, that there is great uncertainty about precisely when these systems will change.
Hopes
While the head of the UN Climate, on Wednesday December 6, the last day of the first week of COP28, urged the negotiators present to move away from “postures” to move towards a compromise despite the differences on fossil fuels, Other recently released data show the scale of the challenge. Scientists announced on December 5 that this year’s global fossil fuel emissions were on track to reach record level of around 37 billion tonnes of CO₂, or 1.1% more than in 2022. And Climate Action Tracker, a consortium that monitors climate policies, estimates that countries’ current commitments to reduce their emissions, in line with the Paris agreement, could lead to a warming of… 2.5°C above pre-industrial levels by 2100. How far away the time for harmony seems after the signing of a text deemed “historic” in the French capital only eight years ago.
However, the more greenhouse gas emissions increase, the more warming intensifies. Consequence: the climatic tipping points are getting closer. Scientists particularly fear a snowball effect. For example, a disintegration of the Greenland ice sheet could lead to an abrupt change in the Atlantic meridional overturning circulation, an important current that provides most of the heat to the Gulf Stream. This, in turn, could intensify the El Niño Southern Oscillation, one of the most powerful weather phenomena on the planet. Sina Loriani, of the Potsdam Institute for Climate Impact Research and co-author of the Global Tipping Points study, said tipping risks could be disastrous and should be taken very seriously, despite remaining uncertainties .
All of this paints a bleak picture of the climate outlook. But the report also gives notes of hope. In particular, it lists potential positive tipping points in social, political and economic systems which, if crossed, could result in climate benefits. Scientists say they have already seen a tipping point, as the falling cost of wind and solar power leads to a reduction in investment in fossil fuels. In France, the government adopted a circular on Wednesday December 6 aiming to reduce its greenhouse gas emissions by 5% per year until 2027. Good news, which, if it follows one another at the same pace as the alarmist reports , could ultimately prove the darkest predictions right.