What Should We Know About Forest Biomass to Better Understand the Global Carbon Balance?

What Should We Know About Forest Biomass to Better Understand the Global Carbon Balance?


Richard.A. Houghton
Woods Hole Research Center
Woods Hole, MA



Wednesday October 6, 2004

109 Atmospheric Sciences Bldg 3:30 p.m.



ABSTRACT



The net annual flux of carbon between terrestrial ecosystems and the atmosphere is dominated by two factors: changes in the area of forests and per hectare changes in forest biomass that result from management and regrowth. While these factors are reasonably well documented in countries of the northern mid-latitudes as a result of systematic forest inventories, they are uncertain in the tropics. Recent estimates of carbon emissions from tropical deforestation have focused on the uncertainty in rates of deforestation. By using the same data for biomass, however, these studies have underestimated the total uncertainty of tropical emissions and may have biased the estimates. In particular, regional and country-specific estimates of forest biomass reported by the FAO indicate systematic changes in biomass that have not been taken into account in recent estimates of tropical carbon emissions. The ‘changes’ more likely represent improved information than real on-the-ground changes in carbon storage. In either case, however, the data have a significant effect on current estimates of carbon emissions from the tropics and, hence, on understanding the global carbon balance.