Monday March 10, 2025
Popular Mechanics —
Whatever your stance is on climate change (it’s real, let’s move on), it’s impossible to have missed the near-ubiquitous call to action to “keep temperatures from exceeding 1.5 degrees Celsius compared to pre-industrial levels.” Over the past few years, the somewhat bureaucratic phrase has become a rallying cry for the climate conscious.
This ambitious target first surfaced following the Paris Climate Agreement, and describes a sort of climate threshold—if we pass a long-term average increase in temperature of 1.5 degrees Celsius, and hold at those levels for several years, we’re going to do some serious damage to ourselves and our environment.
Well, a paper from the University Western Australia Oceans Institute has some bad news: the world might’ve blown past that threshold four years ago. Published in the journal Nature Climate Change, the paper reaches this conclusion via an unlikely route—analyzing six sclerosponges, a kind of sea sponge that clings to underwater caves in the ocean. These sponges are commonly studied by climate scientists and are referred to as “natural archives” because they grow so slowly. Like, a-fraction-of-a-millimeter-a-year slow. This essentially allows them to lock away climate data in their limestone skeletons, not entirely unlike tree rings or ice cores.