If an alien civilisation lands, millions of years from now when humans are a distant memory, what will they find? Our cities will be long gone; our sturdiest monuments and greatest buildings will be dust. But if they bring a geologist with them, they may be able to read the story of our existence from the stones they walk on. In Berlin, yesterday, a group of scientists met to discuss just what that story will tell – and how important a story it is.
Humans have existed in our modern form for only about 200,000 years. In geological terms, barely the blink of an eye: geologists measure the history of the Earth in millions of years. But some think that humanity’s impact on the planet in that time – and especially in the past few hundred years – has changed the planet so much that we are now living in a new epoch: the Anthropocene. We have caused a mass extinction, and changed the composition of the atmosphere, they say. Our effect on the planet is as great as that of the end of the last ice age.
http://www.telegraph.co.uk/science/11167165/Scientists-wonder-what-in-the-world-will-we-leave-behind.html