When and how did the Anthropocene begin?

摘要

In March of this year, Nature published a stimulating article by Simon Lewis and Mark Maslin entitled 'Defining the Anthropocene' (Lewis and Maslin, 2015). In it, they proposed criteria for determining the formal onset of the Anthropocene Epoch and from these, derived new starting dates. They proposed two alternatives, ad 1610 and ad 1964. The former date lies some two centuries before the date proposed by Crutzen and Stoermer (2000) in their paper introducing and providing both a definition and a starting point for the Anthropocene. The latter date is over a decade later than an alternative and increasingly discussed onset date arising from Steffen et al.'s paper (2007) identifying a 'Great Acceleration' in detectable human impact on the Earth System beginning in the mid 20th century. These new proposals have provoked a great deal of interest and debate. In this issue of The Anthropocene Review, we have tried to provide a timely account of this debate. The first four papers comprise contrasted 'comments' on the Nature article, followed by 'replies' from its authors. The issues raised are far from forming a sterile debate on starting dates. They are full of, and indeed go well beyond, the engaging scientific basis upon which the contrasted points of view rest. For this reason, I have taken the decision to regard them as 'comments' and 'replies' despite their length. As well as making it possible to view them as a linked set in the present volume of the Review, it has also allowed their appearance online before the provocative impact of the original Nature paper fades. I hope readers will enjoy the debate and find the ideas put forward and issues raised every bit as stimulating as I have as Editor.