VOLCANOES were more destructive in ancient history. Not because they were
bigger, but because the carbon dioxide they released wiped out life with greater
ease.
Paul Wignall from the University of Leeds was investigating the link between
volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off
large numbers of animals, but all the mass extinctions over the past 300 million
years coincided with huge formations of volcanic rock. To his surprise, the
older the massive volcanic eruptions were, the more damage they seemed to
do.
Wignall calculated the “killing efficiency” for these volcanoes by comparing
the proportion of…


