If we want to know how the Earth's biosphere is going to respond to the things that humans are doing to the planet right now, the only evidence that we have is how biotic systems have responded in the past.

The Anthropocene essentially would be the time of human influence on the planet. That's controversial though, because geology is a retrospective discipline. The rocks of the Anthropocene haven't been deposited yet, really.

If you were back in the Cretaceous Period - the last of the time of the dinosaurs - and you were driving from New York to Philadelphia on the New Jersey Turnpike, you would be driving across water.

In our case, we are in the Cenozoic Era, which started at the end of the time of the dinosaurs. We are in the Quaternary Period, which is within the Cenozoic Era. And within the Quaternary, we are in the Holocene Epoch.

Certainly, we have entered into a new age on our planet.

We're changing things, in many cases in irreparable ways, and that will certainly be recorded in the geological record.

If we want to know how the Earth's biosphere is going to respond to the things that humans are doing to the planet right now, the only evidence that we have is how biotic systems have responded in the past.