Nearly 200 countries began online negotiations Monday to validate a UN scientific report that will anchor the autumn summits responsible for preventing a global climate catastrophe.
“The report that you are going to finalize is going to be very important around the world,” World Meteorological Organization chief Petteri Taalas told some 700 delegates via Zoom.
The assessment by the Intergovernmental Panel on Climate Change (IPCC) “is crucial for the success of the Glasgow climate conference in November,” he said.
Record heat waves, floods and droughts on three continents in recent weeks – all amplified by global warming – have increased the pressure for decisive action.
“For years, we have warned that this is all possible, that all of this was going to happen,” Patricia Espinosa, UN climate chief, said in a statement.
A key G20 summit with climate on the agenda is scheduled for the end of October.
The world is a different place since the IPCC’s last comprehensive overview in 2014 on global warming, past and future.
Persistent doubts that warming was accelerating or that it was almost entirely human in origin, along with the falsely reassuring idea that climate impacts are tomorrow’s problem, have since evaporated in the haze of deadly heat waves. and fires.
Another milestone since the last volume of the IPCC: the Paris Agreement was adopted, with a collective promise to cap the rise in temperature at the surface of the planet at “well below” two degrees Celsius (3.6 degrees Fahrenheit) above late 19th century levels.
Carbon pollution from burning fossil fuels, methane leaks, and farming has pushed the thermometer up to 1.1 degrees Celsius so far.
# photo1 The 2015 treaty also calls for an ambitious 1.5 degree Celsius warming limit, with many parties no doubt assuming that this target could be safely ignored.
But a special IPCC report in 2018 showed just how devastating 2 degrees Celsius would be for humanity and the planet.
– Low-balling le danger –
“1.5 Celsius has become the de facto target” – and proof of the influence of the IPCC in shaping global policy, Peter Thorne, senior author of the IPCC and professor at Maynooth University, told AFP .
Scientists have calculated that greenhouse gas emissions must decrease by 50% by 2030 and be completely eliminated by 2050 to stay within the 1.5 degree Celsius range.
“The reality is that we are not on track to meet the Paris Agreement goals of limiting climate change to 1.5 degrees by the end of the century,” Espinosa said.
According to current trends, she noted, the world will heat up more than double.
A third radical change in the past seven years concerns science itself.
“Today we have better climate projection models and longer observations with a much clearer signal of climate change,” climatologist Robert Vautard, also lead author of the IPCC and director of the IPCC, told AFP. French Institute Pierre-Simon Laplace.
# photo2 Arguably the biggest breakthrough are so-called attribution studies, which for the first time allow scientists to quickly quantify how much climate change has boosted the intensity or likelihood of an event extreme weather.
For example, days after the deadly “heat dome” that burned Canada and the western United States last month, the World Weather Attribution consortium calculated that the heat wave would have been virtually impossible without the warming caused. by the man.
– ‘Transformational change’ –
Starting Monday, representatives from 195 countries, with leading scientists by their side, will review a 20-30 page “Summary for Policymakers” line by line, word by word.
The virtual meeting for this first part – covering the physical sciences – of the three-part report will take two weeks rather than the usual one, with publication of the document scheduled for August 9.
The second part of the report, to be published in February 2022, deals with the impacts.
Leak project obtained by AFP warns climate change will fundamentally reshape life on Earth in coming decades, even if global warming carbon pollution is brought under control, calls for fearful ‘transformational change’ that future generations face much worse.
Part Three, to be unveiled the following month, examines solutions to reduce emissions.
Based almost entirely on published research, the report reviewed this week will likely predict – even under optimistic scenarios – a temporary “overshoot” of the 1.5 degree Celsius target.
There will also be a new focus on so-called “low probability and high risk” events, such as irreversible melting of ice caps that could raise sea levels by several meters and the decomposition of permafrost laden with greenhouse gases. tight.
“The comments amplifying the change are stronger than we thought and we may be approaching some tipping points,” said Tim Lenton, director of the Global Systems Institute at the University of Exeter.
© 2021 AFP