Here’s a little warning from our finny friends in the Great Dying a.k.a. the Permian–Triassic extinction event.
There it is in the headline in Cosmos, “Ocean oxygen loss caused Earth’s largest extinction.”
Maybe you pass it by because events occurring at the Permian-Triassic boundary, 251 million years ago, while interesting, are not as compelling as, say, snake sex or quantum matter waves.
But the headline really should read:
Climate change caused Earth’s largest extinction.
Oh, now, that might make you jump.
The Cosmos article discusses a paper published October 11th in Proceedings of the National Academy of Sciences.
According to the paper, anoxia in the world’s oceans triggered by climate change may have caused the death of 90% of ocean species. The climate change itself was triggered by the release of greenhouse gases in a massive volcanic eruption.
According to Thomas Algeo of the University of Cincinnati who was involved in the study,
The eruption released large quantities of carbon dioxide (CO2) and methane (CH4), both of which are greenhouse gases, and this resulted in a rapid climate warming that reduced the solubility of oxygen (O2) in ocean-surface waters.
Warmer water retains less oxygen than cooler water. Ocean species need this oxygen to breathe.
A second consequence was accelerated erosion of soils, which shed a lot of nutrients into the marine environment, triggering algal or bacterial blooms that consumed dissolved oxygen. These factors worked in concert to produce widespread anoxic conditions in the Permian-Triassic global ocean.
The accelerated erosion of soils occurred, of course, because climate change causes desertification and drastically increases precipitation events, both of which tend to sweep soils into the sea.
Rapidly increasing greenhouse gases. Climate change. Warming oceans. Soil erosion. Growing patches of anoxia. Accelerating extinctions.
It happened during the Great Dying. It’s happening now.
Now that’s almost as exciting as snake sex.