PARIS – Nearly 200 nations start online negotiations today to validate a United Nations science report that will anchor autumn summits charged with preventing climate catastrophe on a planetary scale.
Record-smashing heat waves, floods, and drought across three continents in recent weeks, all amplified by global warming, make the Intergovernmental Panel on Climate Change (IPCC) assessment more than timely.
“It’s going to be a wake-up call, there’s no doubt about that,” said Richard Black, founder and senior associate of the London-based Energy and Climate Intelligence Unit.
The report, he noted, comes only weeks ahead of a UN General Assembly, a G20 summit, and the 197-nation COP26 climate summit in Glasgow.
The world is a different place since the IPCC’s last comprehensive assessment in 2014 of global heating, past and future.
Lingering doubts that warming was gathering pace or almost entirely human in origin, along with the falsely reassuring notion that climate impacts are tomorrow’s problem, have since evaporated in the haze of deadly heat waves and fires.
Another milestone since the last IPCC: the Paris Agreement has been adopted, with a collective promise to cap the planet’s rising surface temperature at “well below” 2°C, above late-19th century levels.
Carbon pollution from burning fossil fuels, methane leaks, and agriculture has driven up the thermometer 1.1°C so far, and emissions are rising sharply again after a brief, Covid-19-imposed interlude, according to the International Energy Agency (IEA).
The 2015 treaty also features an aspirational limit on warming of 1.5°C, with many parties no doubt assuming this goal could be safely ignored.
But an IPCC special report in 2018 showed how much more devastating an extra 2°C would be, for humanity and the planet.
“1.5°C became the de facto target” – and proof of the IPCC’s influence in shaping global policy, IPCC lead author and Maynooth University professor Peter Thorne said.
Scientists have calculated that greenhouse gas emissions must decline 50% by 2030, and be phased out entirely by 2050 to stay within the range of 1.5°C.
A third sea change over the last seven years is in the science itself.
“Today we have better climate projection models, and longer observations with a much clearer signal of climate change,” climatologist Robert Vautard, also an IPCC lead author and director of France’s Pierre-Simon Laplace Institute, said.
Arguably the biggest breakthrough is so-called attribution studies, which for the first time allow scientists to rapidly quantify the extent to which climate change has boosted an extreme weather event’s intensity or likelihood.
For example, within days of the deadly “heat dome” that scorched Canada and the western US last month, the World Weather Attribution consortium calculated that the heat wave would have been virtually impossible without man-made warming.
But after-the-fact analysis is not the same as foresight, and the IPCC – set up in 1988 to inform UN climate negotiations – has been criticised by some for low-balling the danger, a pattern that Harvard science historian Naomi Oreskes has called “erring on the side of least drama”. – AFP, July 26, 2021
