There is an interesting piece in this week’s Science regarding the discussions that geologists are having at their meeting this week, as to whether the epoch we are in right now should be officially called the “Anthropocene”, and if so, when it should start.
It may seem like one of those nerd debates that doesn’t really matter to normal folks, but this one really does. The article has some excellent graphics and truly frightening statistics to anchor this debate. Consider this: 80% of the Earths’ land area has been altered by humans, and 90% of the biomass represented by mammalian species is currently tied up in either human or domesticated livestock bodies. Think about that…. our bodies and our cows, goats and sheep outweigh all of the lions and tigers and bears out there, not to mention the elephants, whales, and gorillas.
Wow. That one took me a while to process.
So what does this say about our future on this planet, or even the future of our planet? Back in 1986, Peter Vitousek* sounded an alarm regarding our increasingly heavy footprint, estimating that humans soaked up about 40% of the planet’s Net Primary Productivity, a measure of how much sunlight plants convert into biomass. That doesn’t leave much left for the millions of species with which we share this rock. And unfortunately, our fate is tied up with most of those millions; if they go, there is no guarantee that we won’t go too.
*Vitousek P, Ehrlich P, Ehrlich A, Matson P. 1986. Human appropriation of the products of photosynthesis. BioScience 36:368-373.