While I planned my latest post to be about the book launch of A Climate of Hope: Church and Mission in a Warming World at the Surrender conference, I've just been reading a paper from the journal Nature about the anthropocene, the idea that humans have so modified the planet that we should be speaking about a new geological age.
The article entitled Defining the Anthropocene by Simon Lewis and Mark Maslin examines a variety of possible definitions. Bill Ruddiman developed his Early Anthropocene Theory to suggest that the origin of modern agriculture has helped control greenhouse gas concentrations. For example, the onset of rice agriculture has meant more regions where methanogenic archaea (a primitive form of bacteria though of a different branch of life altogether) could thrive and increase atmospheric methane.
Ruddiman also suggested that plagues could result in a dip in CO2 concentrations when population reduction led to farmland reverting to forest. One of the rather sobering ideas in Lewis and Maslin's work is that the arrival of Europeans in the Americas saw a drop from about 61 million in 1492 to 6 million by 1650; the result of diseases, war, famine and enslavement. From ice core studies, a drop of 7-10 ppm in CO2 concentrationswas observed about 1610. This was a cool period during the Little Ice Age, a largely Northern Hemisphere phenomena.
It's a sober reminder that human hubris, violence and ignorance damage both human flourishing and that of the planet, and that all of our theorising in theology and the social sciences (as well as natural sciences?) need to be firmly post-colonial.
Even if 1610 isn't the best candidate for the beginnings of the anthropocene, it still marks a significant change in the state of affairs of the Earth.