When interests collide
Mar 13, 2007

Treehugger has just run a story about carbon sequestration; a name for techniques which reduce our emissions of carbon dioxide into the atmosphere by putting them into other places. Personally I've always been a little skeptical of the idea, due perhaps to a limited understanding of it. But the recent Treehugger story has, for me at least, really driving the point home about how it can be a good and useful thing. Why did this seemingly innocuous story about a popular subject among environmentalists make so much more of an impact on me than others?, you might be asking. Well, the answer is that this story has a direct relation to another interest of mine: pre-Columbian American civilizations. The story talks about one method of carbon sequestration that brings about other benefits beyond reducing our emissions. It's referred to as 'incorporating bio-char into the soil', which is another name for creating terra preta (and you'll notice a similarly named link at the end of the story). Terra preta is the name for a type of soil found in Amazonian regions of South America. Ordinarily the soil in the Amazon is nearly completely devoid of nutrients due to the near constant 'rainfall' caused by the rainforest. There are, however, patches of earth which not only defy this trend but are incredibly fertile. These patches, termed terra preta, or 'dark earth', because of their uncharacteristically dark coloration for the region, are believed to have been purposefully created as a soil management project by pre-Columbian American civilizations perhaps as early as 720 B.C. I was already familiar with the nature and benefits of terra preta due to my archaeological interests, and so the mention of using it as a form of carbon sequestration really brought the whole concept into focus for me. An important component of terra preta is the high levels of charcoal in the soil (hence the term 'bio-char'). Charcoal, as we all know from our high school chemistry classes, is a form of carbon, and therefore one possible destination for the carbon that would otherwise be forming carbon dioxide to be pumped into the atmosphere. This, I suppose, is the perfect example of why I'm interested in archaeology. Not only are ancient cultures fascinating in their own right, but they can actually have important lessons, and even technologies, to teach us that can help us with our own modern problems.
blog comments powered by Disqus