This raises an intriguing question, according to Beatrice Cointe, a sociologist at France’s National Center for Scientific Research and co-author of a recent study on the history of the 1.5C goal.
“How did a nearly impossible goal become the point of reference for climate action?” He asked.
And what will happen when the world experiences its first full year of warming at or above 1.5C, which the IPCC says could easily happen within a decade, even under aggressive emissions reduction scenarios?
“The target appears increasingly unattainable,” Cointe and co-author Hélène Guillemot, a historian of science at the Center Alexandre-Coeur, wrote in the journal Wires Climate Change.
“And yet the calls to ‘survive 1.5C’ are growing louder.”
The background story of 1.5C’s goal reveals the interplay of science and politics, with one driving and shaping the other.
Going into the 2015 climate talks, the success of the Paris Agreement did not seem likely to improve significantly on the 2C target the 195 nations had already set.
But a scientific assessment delivered ahead of the December summit by a UN technical body sounded a stark warning about the dangers of a +2C world and suggested greater ambition might be wiser.
“While the science on the 1.5C limit is less robust, efforts should be made to lower the defense line as much as possible,” it concluded.
Meanwhile, a growing coalition of developing countries had gathered behind the 1.5C goal, eventually joined by the European Union and the United States.
Rising giants and oil exporters put pressure on their fossil-fuel-dependent economies by fearing constraints.
“China was against it, India was against it, Saudi Arabia fought us with all its might,” Salimul Haq, director of the International Center for Climate Change and Development in Dhaka, recalled.
Even today these countries remain indifferent to this idea.
But in the end, nearly 200 countries committed to cap warming at “well below 2C” while “continuing efforts to limit temperature rise to 1.5C.”
‘a moral goal’
It was a stunning diplomatic coup. However, many scientists were less than thrilled.
“It will be very difficult – if not impossible – to keep warming below 1.5C during the whole of the 21st century,” Joeri Rogelj, a climate modeler currently at Imperial College London, has been instrumental in the technical report. Time.
But because the target was part of the Paris Agreement, nations called on the IPCC – which exists to brief policymakers on climate science – for a “special report”.
The resulting blunder, delivered in October 2018, left no doubt as to the difference of half a degree: a 1.5C world would see profound changes but remain livable; A 2C world could tip the climate system into overdrive, undermining our ability to adapt, it warned.
Today, the IPCC – including Rogelj, the lead author of the 2018 report – insists that the 1.5C target is technically feasible.
But that conclusion hangs by the thinnest of threads.
There’s no scenario that avoids “overshooting” the target, and getting the temperature back under the wire would require extracting billions of tons of CO2 out of thin air, something we can’t yet do on a large scale.
But whether the 1.5C target is feasible, others say, may be missing the point.
“Achieving 1.5C in the agreement was a moral goal,” Haque told AFP shortly after the Paris Agreement was signed.
“It’s our leverage, we’ll use the whip to whip everyone on the back so they can move faster,” he said.
“Whether we achieve it or not it is going down a dark path. From now on, it is about raising the ambition.”
Lead author Piers Foster, director of the University of Leeds Priestley International Center for Climate and coordinator of the IPCC, described the 1.5C objective as a “huge, but not impossible, task”.
“Hopefully the IPCC report can add to the urgency going forward,” he told AFP. “If this is ignored, we will have to abandon 1.5C.”