Anyone concerned by the idea that people might try to combat global warming by injecting tons of sulfate aerosols into Earth’s atmosphere may want to read an article in the May 1 issue of the journal Geology.
Anyone concerned by the idea that people might try to combat global warming by injecting tons of sulfate aerosols into Earth’s atmosphere may want to read an article in the May 1 issue of the journal Geology.
In the article, a Washington University in St. Louis scientist and his colleagues describe what happened when pulses of atmospheric carbon dioxide and sulfate aerosols were intermixed at the end of the Ordivician geological period more than 440 million years ago.
The counterpart of the tumult in the skies was death in the seas. At a time when most of the planet north of the tropics was covered by an ocean and most complex multicellular organisms lived in the sea, 85 percent of marine animal species disappeared forever. The end Ordivician extinction, as this event was called, was one of the five largest mass extinctions in Earth’s history.
Although the gases were injected into the atmosphere by massive volcanism rather than prodigious burning of fossil fuels and under circumstances that will never be exactly repeated, they provide a worrying case history that reveals the potential instability of planetary-scale climate dynamics.
Read more at Washington University in St. Louis
Image: Washington University in St. Louis geologist David Fike holds a 443-million-year-old slab of Ordovician limestone from Anticosti Island in Quebec that is sprinkled with the fossilized remains of marine creatures killed during a cooling pulse. New research suggests the mass extinction, which took place 440 million years ago was caused by a sequence of events that allowed volcanoes to inject reflective aerosols above the tropopause. (Credit: Jerry Naunheim Jr./WUSTL Photos.)
