Photo Credit: kevindooley via Flickr/CC BY
Humans activities now leave an impact on the natural world in just about every manner imaginable -- from harvesting resources for consumption to emitting CO2 as a byproduct of generating energy to burning fossil fuels to power our transportation, the collective footprint of those various activities is massive indeed. But what about other widespread acts that humans have engaged in throughout history? What else has left a mark on the world's climate? What, for instance, is the carbon footprint of war? Traditionally, it's been a huge net negative, according to a new scientific study by Julia Pongratz of the Carnegie Institution for Science, published in the journal Holocene. And the reasons for that are pretty grimly obvious: one indisputable result of war is that it removes a bunch of people from the population. Once a bunch of people are removed from the population, they're no longer able to harvest resources and so forth -- and it gives ol' momma nature some recovery time.
It all comes down to a trade-off between people and trees: when a brutal war or devastating plague significantly reduces a human population, forests have the chance to re-grow and absorb carbon dioxide, mitigating the greenhouse effect.Alright! All we have to do is kill each other in a series of bloody, drawn-out conflicts -- pretty much what we probably would have done anyways -- and we can preserve the earth's climate! Somewhere, the Malthusians are cheering. But what's this? "However, Pongratz points out, any sighs of relief forests drew from human war and death failed to overcome the climate damage caused by a long and continuing history of deforestation."
Pongratz reconstructed global land cover from 800 AD to the present and modelled the carbon cycle for the same time period in order to test how land usage influenced climate change. She found, for example, that during the Mongol invasions in Asia (1200 - 1380), which some historians estimate killed at least 15 million people, newly flourishing trees in once deforested areas inhaled nearly 700 million tons of carbon from the atmosphere - an amount equivalent to the world's total annual demand for gasoline today.
Alas. It looks like not even warmongering is going to get us out of the climate pickle. Too bad -- we're so good at that.