Sack Lunch Seminar (SLS)

Singular Blow-up at the Permian-Triassic Boundary



Geochemical studies show that the Permian-Triassic extinction (~252 Ma)
is accompanied by a rapid (~10 Kyr) depletion in the carbon
isotopic composition of seawater. Here we show that this isotopic
event is consistent with an incipient singularity in the growth of the
oceans' reservoir of dissolved inorganic carbon, the eventual size of
which exceeds any possible modern source. The singular influx of CO2
indicates a fundamental nonlinearity in the carbon cycle that, in
principle, allows prediction of the extinction event about 100 Kyr in
advance. Its identification also suggests that any hypothesis for the
extinction's cause should predict such a blow-up. We identify a
biological mechanism with this property and discuss its relevance to
observations.