The Anthropocene biosphere

The geological recordpreserves evidence for two fundamental stages in the evolution of Earth’s biosphere, a microbial stage from ~3.5 to 0.65 Ga, and a metazoan stage evident by c. 650 Ma. We suggest that the modern biospherediffers significantly from these previous stages and shows early signs of a new, third stage of biosphereevolution characterised by: (1) global homogenisation of flora and fauna; (2) a single species ( Homo sapiens) commandeering 25–40% of net primary productionand also mining fossil net primary production(fossil fuels) to break through the photosynthetic energy barrier; (3) human- directed evolutionof other species; and (4) increasing interaction of the biospherewith the technosphere (the global emergent system that includes humans, technological artefacts, and associated social and technological networks). These unique features of today’s biospheremay herald a new era in the planet’s history that could persist over geological timescales.