The synthesis of nine years of IPCC work on the climate sounds Monday as a stark reminder of the need for humanity to finally act radically during this crucial decade to ensure "a livable future".
This synthesis, which succeeds that of 2014 and will have no equivalent in the current decade, is "a survival guide for humanity", underlined the secretary general of the UN, António Guterres.
"This report is a message of hope," Hoesung Lee, chairman of the Intergovernmental Panel on Climate Change (IPCC), told AFP.
“We have the know-how, the technology, the tools, the financial resources and everything we need to overcome the climate problems that we have identified” but “what is missing for the moment is political will strong in order to solve them once and for all", judges the Korean economist.
This scientific consensus of the IPCC will be the factual basis for the intense political and economic negotiations of the coming years. Starting with the UN climate summit in December in Dubai, the COP28, where an initial assessment of the efforts of each country within the framework of the Paris agreement will be unveiled and where the future of fossil fuels will be fiercely negotiated.
During the long IPCC discussion sessions in Switzerland over the weekend, Saudi Arabian negotiators fought to water down sentences on the central role of fossil fuels (oil, gas, coal). The place given in the 36-page "summary for decision-makers" to the legitimacy of CO2 capture technologies bears their mark, according to some observers, who see in them potential "license to burn".
Global warming will reach 1.5°C compared to the pre-industrial era from the years 2030-2035, warns the IPCC, while the temperature has already risen by almost 1.2°C on average.
This projection is valid in almost all scenarios of human greenhouse gas emissions in the short term, given their accumulation over the past century and a half.
The CO2 emissions that would emanate from existing fossil infrastructures, if they are not equipped with means of capture, would be enough on their own to tip the world towards 1.5°C.
But "deep, rapid and prolonged reductions in emissions (...) would lead to a visible slowdown in global warming in about two decades", also writes the group of scientists on behalf of the UN.
"This summary report highlights the urgency of taking more ambitious action and shows that if we act now, we can still ensure a livable future for all," said IPCC President Hoesung Lee.
"For any level of future warming, many climate-associated risks are higher than estimated" in the previous 2014 summary report, the scientists write.
They are based on the recently observed multiplication of extreme weather events such as heat waves, and new scientific knowledge, for example on corals.
"Due to the inevitable rise in sea levels, the risks to coastal ecosystems, people and infrastructure will continue to increase beyond 2100," they also point out.
The issue of "loss and damage" caused by global warming and already suffered by some countries, in particular the poorest, will be one of the topics of discussion at COP28.
"Climate justice is crucial because those who have contributed the least to climate change are disproportionately affected," said Aditi Mukherji, one of the authors of the synthesis.
"The hottest years we have experienced so far will be among the coolest within a generation", summarizes for AFP Friederike Otto, co-author of the synthesis, which represents this reality by a graphic colored in red more or less dark.
"Some things are easier to get governments to accept when it's in infographics" rather than explicitly in text, she explains.
The past eight years have already been the hottest on record globally. In the future, they will therefore be among the coolest of the century, whatever the levels of greenhouse gas emissions.
This observation underlines the need to combine efforts to adapt to climate change and those to reduce emissions so as not to make it even worse.
“The economic and social benefits of limiting global warming to 2°C exceed the cost of the measures to be put in place”, assure the experts.
But any additional procrastination would increase the step to be taken, notes the IPCC, while the world is already benefiting from the rapid progress of renewable energies.
"From 2010 to 2019, costs have fallen sustainably for solar energy (85%), wind power (55%) and lithium batteries (85%)", recalls the summary.
In addition to the effect on the climate, accelerated and sustained efforts "would bring many co-benefits, particularly for air quality and health", write the scientists, who do not hide the price to be paid: "in the short In the long term, actions involve high initial investments and potentially radical changes".
03/20/2023 14:27:22 - Paris (AFP) - © 2023 AFP
