Are we living in the Anthropocene? - Part 2

Google the Anthropocene and you will be overwhelmed by news articles and research into this newly proposed geological time – my latest blog post being somewhere down the list. I wanted to explore both sides of the argument that we are living in a human-influenced geological time, but there was just too much to squeeze into one post. I have already highlighted arguments in support of the Anthropocene but now let’s take a look at why we might all be jumping on the Anthropocene band wagon a little too quickly…

Harmful human impacts on Earth paint such a negative picture it’s hard not to hand yourself straight over to the Anthropocene. We have become far too accustomed to hopelessly accepting there is nowhere natural left on Earth.  However, we could be overestimating the extent of human influence at a local scale. In Conservation Biology, 2001, Caro et al. suggest there are still ecosystems that we have affected a lot less than we fear, called intact ecosystems. 

An ecosystem is described as intact if the majority of native species are still present and play the same functional roles as they did before extensive human settlement. These include areas of low human density - like equatorial, subtropical and arctic latitudes - and high biodiversity, which do still exist. The Amazon Rainforest, Canadian Boreal Forests, the Rocky Mountains and lake regions under Antarctic Ice sheets are all examples of regions with intact ecosystems.

Canadian Boreal Forest

I'm not suggesting that the presence of such ecosystems allows us to ignore the rest of the changes humans have caused around the globe, but it is valuable to remember there are still natural places left on Earth, and to decide how these need to be protected. 

As Chris D. Thomas reminds us in Nature, change isn't always a bad thing. Even if we are living in the Anthropocene, not all human activity has been detrimental to biodiversity. Humans are often responsible for introducing invasive species to ecosystems, which is commonly believed to be harmful to biodiversity. Stuart L. Pimm in The Future of Biodiversity, 1995, suggests that invasive species are a factor at the centre of most extinction mechanisms. However, according to Thomas, invasive species can actually increase diversity because less than one species dies out on average when a new species is introduced. 

It may be concerning that human activity such as development and land use change can displace multiple species from the original habitat, in turn supporting a smaller range of species and losing diversity. However, these man made areas create new habitats which promote speciation. A greater diversity of habitat type correlates to a greater biodiversity. Although you might think it is more important to conserve existing species, it is also important to consider future species and hybrids evolving during our time - or should I say the Anthropocene?

Whether human impacts to the Earth have been positive or negative, the spread of anthropogenic influence has only left few natural areas, so the great deal of support out there for the Anthropocene is understandable. If we really are in this new geological epoch, the question to ask next is when did it begin..?

The Earth in human hands