Expansion of Farmland and Climate Change

Green cornfield under a summer sky.

As the world’s population grows and consumes more food, a natural effect is the expansion of farmland.  And at first glance, that doesn’t sound like too bad a thing; after all, growing plants absorb atmospheric CO2 and convert it into carbohydrates and innumerable other carbon-based molecules that form the structure of the plant itself.

The problem is that, unlike the forests that were cleared to create this farmland, the carbon cycle associated with all the plants in question is very short.  Yes, CO2 is absorbed and converted to something else, but then the plant is ingested by either a person, or an animal, perhaps a cow, that will be ultimately eaten by a person, and the CO2 is then rereleased into the atmosphere.

By contrast, the trees in the forests have lives that last decades, or perhaps centuries, enabling the sequestration of carbon for considerable periods of time.