Most of the world's major waterways have been diverted or dammed or otherwise manipulated - in the United States, only two per cent of rivers run unimpeded - and people now use half the world's readily accessible freshwater runoff.

Zalasiewicz is convinced that even a moderately competent stratigrapher will, at the distance of a hundred million years or so, be able to tell that something extraordinary happened at the moment in time that counts for us as today. This is the case even though a hundred million years from now, all that we consider to be the great works of man—the sculptures and the libraries, the monuments and the museums, the cities and the factories—will be compressed into a layer of sediment not much thicker than a cigarette paper.

As best as can be determined, the world is now warmer than it has been at any point in the last two millennia, and, if current trends continue, by the end of the century it will likely be hotter than at any point in the last two million years.

It may seem impossible to imagine that a technologically advanced society could choose, in essence, to destroy itself, but that is what we are now in the processnof doing.

Letting things slide is always the easiest thing to do, in parenting no less than in banking, public education, and environmental protection. A lack of discipline is apparent these days in just about every aspect of American society. Why? This should be is a much larger question, one to ponder as we take out the garbage and tie our kids' shoes.

Well in the scientific there is virtually no debate over certain things. For example, that we are changing the world. Humans are changing the world very radically, very dramatically. Climate change, which I assume is one of the points you're alluding to, is at the heart of this.

Somewhere in our DNA must lie the key mutation (or, more probably, mutations) that set us apart—the mutations that make us the sort of creature that could wipe out its nearest relative, then dig up its bones and reassemble its genome.