Government representatives and climate scientists from nearly 200 countries have approved an assessment of a decade of published science about the existential danger of global warming – and what to do about it.
The UN Intergovernmental Panel on Climate Change (IPCC) meeting in Interlaken, Switzerland, signed off on the document on Sunday morning after two overnight negotiation sessions at the weekend.
What is known as the “synthesis report” is due to be formally released on Monday, and details in less than 30 pages observed and projected changes in Earth’s climate system; past and future impacts such as devastating heatwaves, flooding and rising seas, and ways to halt carbon pollution pushing Earth towards becoming an unliveable planet.
It is the culmination of a global review – the first since the landmark Paris climate agreement of 2015.
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The IPCC met in a joint process with governments and scientists over the past week to close their sixth assessment report, known as AR6.
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The report integrates findings of three working group reports and three special reports published since 2018, which are the most comprehensive and authoritative evidence about human-caused climate change.
The special reports looked at keeping the rise in global temperature to within 1.5 degrees; land use, and impacts on oceans and where water is in solid form, such as ice caps and glaciers.
The latest report will provide insights into the severe impact of climate change on the planet and its people, socially and economically, and is directed at policymakers.
It comes as time left to reach critical 2030 goals under the Paris Agreement is narrowing. This includes putting in place funding to decarbonise the global economy, to ensure vulnerable countries become climate resilient in adapting to the inevitable impacts of global warming, and to scale up nature-based solutions – measures necessary to achieve net-zero carbon emissions by 2050.
IPCC chair Hoesung Lee said the synthesis report would become a “fundamental policy document for shaping climate action in the remainder of this pivotal decade”.
In a video message to delegates, UN secretary general António Guterres said “it could not come at a more pivotal time ... We are nearing the point of no return; of overshooting the internationally agreed limit of 1.5 degrees of global warming.
“Your report last year clearly demonstrated it is possible to limit global warming to 1.5 degrees with rapid and deep emissions reductions across all sectors of the global economy. And your recent reports have also underscored the need to act now,” he added.
In 2021, Mr Guterres noted, they had for the first time found some of the changes to Earth’s oceans, ice and land surface were irreversible. “And that these changes were unequivocally caused by human activity, overwhelmingly due to burning fossil fuels and creating unprecedented levels of greenhouse gases.”
In 2022, they had concluded nearly half the global population was “living in the danger zone of climate impacts”.
Dr Stephanie Roe of WWF, lead author on the IPCC Working Group III report on mitigation, said: “Distilling more than 10,000 pages of climate science from the three working groups and three special reports, the synthesis report will present the most integrated and accessible assessment of climate change drivers, impacts, and mitigation and adaptation solutions in a decade.”
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The evidence showed not enough was being done to respond to this crisis, she added. “With current emissions still at their highest level in human history, we are way off course, and the window to limit warming to 1.5 degrees is rapidly closing.”
The science, however, indicated solutions were within grasp, Dr Roe underlined. “In some cases we have started to implement these solutions, with various countries already achieving sustained emissions reductions, but action is not yet at the scale or speed we need. The sooner and more decisively we act, the sooner people and nature can reap the benefits of a cleaner, safer and more stable future.”
Anusha Narayanan, global project lead against fossil fuel expansion at Greenpeace USA, said: “This report adds an exclamation mark on the need for climate action. New fossil fuel projects – including drilling into carbon bombs from the US Permian Basin to Northwest Australia – are directly undermining the prospects of a habitable planet. The world cannot tolerate one more drop of new oil or gas if we are to meet the goals of the Paris Agreement.”