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In 2015, world leaders convened in Paris and agreed to head off the most life-threatening impacts of climate change by restricting global warming to 1.5 degrees above pre-industrial levels.
The trouble is, there is new scientific evidence that by the time of the Paris climate change conference, we had already blown that threshold.
Ceratoporella nicholsoni, a species of sea sponge that can live for centuries.Credit: NOAA
That’s the conclusion of a new Australian-led study just published in Nature Climate Change. Its authors analysed Caribbean sea sponges to extrapolate historical water temperature from the chemistry of their skeletons.
Cross-sections of the century-spanning sponges revealed the world was already warming during the period regarded by the Intergovernmental Panel on Climate Change (IPCC) as the pre-industrial temperature baseline.
Researchers say their sponge analysis indicates we underestimated warming by 0.5 degrees and had already smashed the 1.5 degree threshold by 2012. Now we’re on the cusp of 2 degrees, says lead author Malcolm McCulloch, an emeritus professor from the University of Western Australia.
Cross-sections of the cryptic sponges were used to approximate global temperatures going back to 1700.Credit: Wikidata
“The clock of climate change has been brought forward by about a decade by our findings,” McCulloch says.
Is this why climate change is impacting agriculture and human health harder and faster than originally thought? Does it explain why sophisticated climate models underestimate the intensity of warming? Is our world already stewing at heat levels we desperately tried to prevent in Paris?
Did a sea sponge just blow up the Paris Agreement?
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06.02.2024
Examine, a free weekly newsletter covering science with a sceptical, evidence-based eye, is sent every Tuesday. You’re reading an excerpt – sign up to get the whole newsletter in your inbox.
In 2015, world leaders convened in Paris and agreed to head off the most life-threatening impacts of climate change by restricting global warming to 1.5 degrees above pre-industrial levels.
The trouble is, there is new scientific evidence that by........
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