The gist:<p>>> Global warming and ocean acidification associated with the immense volcanic CO2 injection to the atmosphere was already fatal and led to the extinction of marine calcifying organisms right at the onset of the extinction. However, the CO2 release also brought further consequences; with increased global temperatures caused by the greenhouse effect, chemical weathering on land also increased.<p>>> Over thousands of years, increasing amounts of nutrients reached the oceans via rivers and coasts, which then became over-fertilized. The result was a large-scale oxygen depletion and the alteration of entire elemental cycles.