This afternoon has been all about deforestation. Environmentalists are busy tracking the debate about an 10-word phrase – mysteriously deleted at the last talks in Bangkok – that is designed to prevent natural forests from being converted into plantations. But I’ll deal with that issue in my next post and move on to a Nature Geoscience commentary that has caused quite a buzz here in Barcelona by downgrading the relative contribution of carbon emissions from deforestation.
The commentary by Guido van der Werf and colleagues (reported by the Guardian here) suggests that emissions from deforestation and degradation are closer to 12 percent of global carbon emissions, rather than the oft-stated 20 percent.
It’s an important finding, although not entirely surprising. Folks at the World Resources Institute in Washington have been looking into the issue as well, and their numbers seem to point in the same direction. Indeed, their assessment of 2005 greenhouse gas emissions, illustrated in a flowchart here, shows deforestation making up just 11.3 percent of the global greenhouse gas emissions; separate out carbon dioxide, and the contribution of deforestation comes out below 15 percent.
I recently chatted about the issue with WRI’s Tim Herzog, who works on greenhouse gas inventories, and he said the problem is that the numbers are still a bit squishy. WRI’s initial analysis converged on 15 percent, with the high end of the range coming in around 20. The report in Nature Geoscience also shows a sizeable uncertainty, ranging from 6-17 percent. It will be interesting to see how these numbers hold up.
Questions quickly arose about whether these new numbers would undermine efforts to include forest carbon in a future climate treaty, but it’s not at all clear why or how better information would stall the debate. Forests are being chopped down, releasing carbon into the atmosphere, and stopping this practice remains a relatively cheap and possibly fast way to reduce greenhouse gas emissions. The only question is how much of the problem we would be solving were we to accomplish that goal.
The van der werf commentary also assesses emissions from peatland fires and degradation in southeast Asia. Including peatland emissions brings the total to 15 percent of global emissions, according to their analysis. As it happens, the conservation group Wetlands International released a new report in Barcelona looking at global peatland emissions. They said their analysis on Southeast Asia is similar to that in the Nature Geoscience, but adding in the rest of the world doubles the impact. Surprisingly, the results suggest that the European Union has the second-highest peatlands emissions, behind only Indonesia.