sampath_ t1_j8wrecl wrote on February 17, 2023 at 2:38 PM

Thank you for the AMA!

You said 3/4 species went extinct in the past events, does that mean there were so many species that we didn't even see? Any estimate on the number?

If a mass extinction happens in 2100, which species are in the line for extinction?

Thanks!

mit_catastrophe OP t1_j8yg7j1 wrote on February 17, 2023 at 9:12 PM

The estimate of 3/4 largely derives from the fossil record of marine animals. And that means that if a particular fossil species has not yet been discovered, we cannot know if it went extinct.

Our own work does not predict extinction in 2100. Instead it identifies the end of the present century as a time when the total CO2 added to the oceans will likely exceed a value that in the past has been associated with mass extinctions. See also our other comment here.