The Sixth Extinction

This compelling and highly readable book one the 2015 Pulitzer Prize for general non-fiction, which will not surprise the reader. The sixth extinction of the title is the current one of the Anthropocene era brought about by ourselves. The background rate of natural extinction is very low, which highlights our current situation as measured in various different ways. The structure of the book entails field reporting on a number of endangered species and environments, interwoven with the fascinating history of how thinking on extinctions evolved. Cuvier was the first to study this in detail and to conclude that cataclysms had taken place. He disagreed with Lamarck and his 'transformisme', while Lamarck rejected the cataclysm theory. This reflects later debates in biology. Kolbert also discusses the influence of Lyell on Darwin, whose theory of natural selection was gradualist. One chapter focuses on ocean acidification - oceans absorb one third of CO2 emissions. It also looks as if global warming may lead to extinction of up to a quarter of species by 2050 - the lowest estimates are between 9% and 13%. The overall message is that extinction events of the magnitude we are creating are very rare in the history of the Earth - and it was striking how human centred the final communiqué from Paris was - personally I saw no reference to loss of biodiversity. The main concern for market economies is cost and opportunity cost. Action on the biodiversity front should surely also be high on our priorities.