I listened to this TED talk by Allan Savory today. TED talks are usually rich in big ideas and poor in specifics. This one is certainly no exception. Even so, it illustrates one potential example of an established phenomenon proving to be somewhat less than the absolute truth.

Savory explains how global climate change isn't just due to an overabundance of burning carbon sources. It's also due to rampant desertification. Many former grasslands have, over the course of the last century or so, lost most of their natural plant life and groundcover, exposing the soil to the elements and increasing water loss by evaporation. The area no longer serves as carbon storage. Savory proposes that the only solution (and here's where I start to get skeptical, at least due to his claims of the "only solution") is to mimic the effects of natural animal movement patterns with livestock. Large herds of cattle usually don't stay in one place for long: they graze for a while and move on to the proverbial greener pastures. Some success has been had in planning the grazing patterns of domestic livestock such that they keep moving through arid areas and stimulate plant growth rather than just consuming it all. The improved plant growth should prevent or even reverse large swaths of desert and allow for enough carbon storage to reduce atmospheric carbon to pre-industrial levels.

It would be nice to think that reversing carbon-based climate change is as easy as shuffling around livestock. I worry about how well the theory scales up; what assumptions are being made about how much desert land can really be reverted to grassland? Do these plans require more livestock than we currently have? What's the potential impact on methane levels? Allan Savory has been talking about holistic resource management for decades, but some actual models of its potential impact on climate change would be nice to see. I presume they exist somewhere. (There's plenty of climate-bloggery about Savory's hypotheses out there but much of it looks less than open-minded.)