Glasgow, Scotland – One phrase, really just a number, dominates the climate negotiations in Glasgow, Scotland: magic and elusiveness 1.5.
This means an international goal to try to limit future warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times. This is a somewhat confusing number that was not the main part of the negotiations just seven years ago and was a political proposal that later proved to be incredibly important from a scientific point of view.
Stopping warming at 1.5 or so could prevent or at least mitigate some of the most catastrophic future impacts of climate change, and for some people, it’s a matter of life and death, as scientists have found in many reports.
The 1.5 is now the “overarching target” of the Glasgow climate talks, called COP26, conference president Alok Sharma said on the first day of the conference. Then on Saturday, he said that the conference, which will be on hiatus on Sunday, is still trying to “keep 1.5 alive.”
For protesters and activists, the phrase is “1.5 to stay alive.”
And 1.5 is closer than it seems. This is because it may sound like another 1.5 degrees from now, but since this is from pre-industrial times, it is actually only 0.4 degrees (0.7 degrees Fahrenheit) from now. The world has warmed 1.1 degrees (2 degrees Fahrenheit) since pre-industrial times.
The point is not that in a year the world will be on average 1.5 times more than in pre-industrial times. Scientists usually mean a multi-year average of more than 1.5 because the temperature rises over a long time, like on an escalator, and has small notches up and down compared to a long-term trend, as if you stepped up or down on an escalator. … …
But it goes fast.
Scientists have calculated that burning fossil fuels can cause carbon pollution before 1.5 degrees Celsius warms up. A report from the Global Carbon Project released a few days ago found that 420 billion tons of carbon dioxide remained in this budget, and this year, humanity has emitted 36.4 billion tons. That’s roughly 11 years that have stayed at current levels – rising, not falling, the report says.
To achieve this, scientists and the United Nations say the world must cut its current emissions by about half by 2030. This is one of three goals set by the UN for success in Glasgow.
“It’s physically possible (to limit warming to 1.5 degrees), but I think it’s almost politically impossible in the real world, apart from miracles,” said Columbia University climatologist Adam Sobel. “Of course, we must not give up propaganda for this.”
A dozen other climate scientists told The Associated Press, in essence, the same thing: if emissions suddenly begin to drop sharply, the world can keep within 1.5 degrees. But they see no sign of what’s going on.
That 1.5 might be a big number right now, but it didn’t start that way.
At the insistence of small island states, which said it was a matter of survival, 1.5 was added to the historic Paris Climate Agreement of 2015 towards the end of the negotiations. In the text of the deal, he is mentioned only once. And this part lists the main goal – to limit warming to “2 degrees Celsius above the pre-industrial level and to make efforts to limit the temperature rise to 1.5 degrees Celsius above the pre-industrial level.”
The 2-step target has been an existing target since the failed 2009 Copenhagen Conference. Initially, the target was interpreted as 2 degrees or, if possible, significantly lower.
But in a sense, both “thresholds” of 1.5 and 2 degrees Celsius are somewhat arbitrary, “said Stanford University climatologist Rob Jackson in an email. “Every tenth degree matters!”
2 degrees was chosen because it is “the highest temperature the planet has ever seen in the last million years or so,” said University of East Anglia climate scientist Corinne Lecker, who wrote the study. carbon budget. Climate Talks in Glasgow.
When the Paris Agreement listed 1.5, the United Nations tasked its Nobel Prize-winning team of scientists, the Intergovernmental Panel on Climate Change, or IPCC, to study what the difference would be on Earth between 1.5 degrees of warming and 2 degrees. degree of insulation.
A 2018 IPCC report found that, compared to 2 degrees, a warming stop at 1.5 would mean:
– Fewer deaths and diseases from heat, smog and infectious diseases.
“Half the number of people would be affected by the lack of water.
– Some coral reefs can survive.
– In the Arctic, there is less chance of a summer without sea ice.
– The West Antarctic ice sheet may not melt irreversibly.
– Sea level will rise by almost 4 inches (0.1 meters) less.
– Half of the smaller number of animals with bones of the spine and plants will lose most of their habitat.
– Significantly less heat waves, rainstorms and droughts.
“For some people, this is without a doubt a lethal situation,” said Natalie Mahovald, lead author of the report, at Cornell University, at the time.
Johan Rockstrom, director of the Potsdam Institute for Climate Impact Research, said in an interview at a conference in Glasgow that the finding that there is a huge difference to Earth with much less damage of 1.5 is the largest climate science discovery in six years.
“When you go over 1.5, it gets worse and worse,” said Rockstrom. “We have more scientific evidence than ever that we really need to aim for a landing at 1.5, which is the planet’s safe climate boundary.”
“As soon as we pass 1.5, we enter the scientific danger zone in terms of increased risk,” said Rockstrom.
In a new August IPCC report, the world will hit 1.5 in the 2030s for each of the four major carbon emissions scenarios they considered.
Even when scientists and politicians talk about 1.5, they usually talk about an “excess”, in which for about ten years the temperature reaches or exceeds 1.5, but then drops, usually with the help of some kind of technology that sucks carbon from air, Stanford Jackson. and others said.
Difficult as it is, negotiators cannot move away from 1.5, said Canadian MP Elizabeth May, who is in her sixteenth climate talks.
“If we don’t stick to 1.5 while it’s technically feasible, we’ll almost be criminals,” May said.