In the war against climate change, peasants are in the front line

FOR people who see stopping deforestation as the quickest climate-change win, Copenhagen seemed a success. Although there is still work to be done on the initiative known as REDD (Reducing Emissions from Deforestation and Forest Degradation), the deal struck in Copenhagen made it into a real thing, not just an idea. The notion of reducing net deforestation to zero was not explicitly mentioned, but it looks much more credible than it did two years ago.

As well as giving heart to the protectors of trees, this outcome is encouraging for people whose focus is not on forests but on fields. Climate and agriculture matter to each other in several ways. On the downside, farming is a cause of deforestation, and also emits greenhouse gases in its own right—perhaps 14% of the global total. On the upside, agriculture can also dispose of heat-trapping gases, by increasing the carbon content of soils. …