It’s a new name for a new geologic epoch—one defined by our own massive impact on the planet. That mark will endure in the geologic record long after our cities have crumbled.
"The pattern of human population growth in the twentieth century was more bacterial than primate," biologist E. O. Wilson has written. Wilson calculates that human biomass is already a hundred times larger than that of any other large animal species that has ever walked the Earth.
This geological epoch happens also to coincide with the sixth mass extinction in Earth's biological history. The earth has seen mass extinctions before. We happen to be in one right now, with some scientists predicting that 75% of the species on earth will have gone extinct by the time the extinction is over. This is a process that has been going on for thousands of years, which many scientists crediting humans as the factor causing the recent mass extiction.
We're firmly in the Age of Man.