Beware of geoengineering using volcanoes' tricks

WE HACK the climate at our peril. Volcanoes spewed so much sulphate into the atmosphere 94 million years ago that the oceans were starved of oxygen and 27 per cent of marine genera went extinct. Geoengineering our climate could inflict a similar fate on some lakes.

So claims Matthew Hurtgen at Northwestern University in Chicago, who with his colleagues measured sulphur isotopes in sediments on the floor of the Western Interior Seaway. The WIS was a vast body of water that divided the continent of North America down the middle at the time.…