QUOTE : A nitrogen spike, indicated in ice-cores and sediments, will be one of the key chemical insignias of the Anthropocene, caused by the mass global use of synthetic nitrogen-rich fertilizers and by fossil-fuel burning. Biodiversity levels are crashing worldwide as we hasten into the sixth great extinction event, while the soaring number of a small number of livestock species ensures the geological posterity in the fossil record of sheep, cows and pigs. We have become titanic world-makers, our legacy legible for epochs to come.