I have just finished listening to the first episode in a short BBC radio series on the Anthropocene. Gaia Vince sets the scene and makes a case for a whole new geological era using short clips from scientists discussing the huge impact humans have on this planet. Humans leave clear geological signatures in the Earth’s surface. This is why some geologists argue we are no longer in the Holocene (the period of relatively stable climate following the end of the last ice age), but in the Anthropocene (from the Greek anthropo- ‘human’ and cene ‘new’), where the human signal is at least as important as all other influences.
The programme lists some quite astonishing facts. 40% of the ice-free land area of this planet is used in agriculture. This doesn’t even include the effects embedded or neighbouring ecosystems, like forests, marshes and rivers. If one includes these that number rises to 75%. We now shift as much nitrogen from the atmosphere into nitrate fertiliser as all the bacteria on the planet (and, as the scientists on the programme points out, there are a lot of bacteria). We alter the hydrological cycle by damming up rivers and preventing sediment reaching the ocea. We mine ‘fossi’ water from aquifers. This water makes it way to the sea and has a significant contribution to sea level rise (greater than that from the warming water or melting land ice). We can even match rivers as a force of erosion of the planet’s crust. We extract and shift a greater mass of mineral material than all the planet’s waterways.
Humans are affecting this planet’s climate, which is one of the ways we are making our mark on the geological record. There are proposals being make to national and international bodies that this new geological era be officially recognised. In doing so humans would put themselves in a new position. In acknowledging the influence we have on this planet we must also acknowledge the responsibilities that come with it. An anthropocentric view might think of this as managing our environment in such a way that it can sustain our descendents (this is more or less the definition of ‘sustainable development’, a fashionable term which has somewhat lost its meaning through repetition).
Most of these huge impacts are inadvertent. Oceanic dead zones caused by over-fertilisation from nitrates are a byproduct of our agricultural system. We don’t mean to kill off life in the oceans in this fashion. The same goes for greenhouse gases, which are byproducts of our demand for energy. Geoengineering – intentional manipulation of the planet’s climate – takes this a step further by adding agency.
The advent of the Anthropocene is a wake-up call to humanity to start thinking seriously about how it wants this planet to be. Like it or not we have this influence. It is better to acknowledge it and manage it than to ignore it.