The Carbon Cycle of Forests - Challenges for Kyoto and Beyond

Interest on the forest carbon cycle has been intensified since the emergence of climate change. While scientist have been keen on the ever increasing of knowledge, recent and future international climate change negotiations, as well as current regulations of the Kyoto Protocol also render it necessary that countries regularly assess and report CO2 emissions and removals. The carbon fluxes are measured using several techniques, and many flux estimates are available at global, regional and country level. Using both scientific estimates, as well as data from greenhouse gas inventories, the paper demonstrates some relevant features of these fluxes, and the carbon cycle at the global level. Terrestrial ecosystems, including forests, play an important role in this cycle, which is demonstrated in the paper by highlighting emissions from deforestations, which account for about one-fifth of all emissions, and the uptake by the terrestrial ecosystem, which amounts to one-third of all emissions. The paper also gives an overview of current estimates of uncertainty from regional to country and to global level. This is thought to be very important, since the estimates of all elements of the carbon cycle are subject to high uncertainties: the uncertainty can be as high as 100% even in the national greenhouse gas inventory of developed countries. Due to the dimensions of forests, to the times scales and complexity of the processes involved, and to the resource requirements and data needs of internationally agreed methodologies, reducing these high uncertainties in currently reported emission and removal estimates is a serious challenge. The paper demonstrates some relevant known sources of uncertainties, and concludes with suggesting several ways of how estimates of the greenhouse gas inventories can be improved in the near future.

SOMOGYI Zoltan; 

2006-02-09

Forest Research Institute

JRC31275