Mapping & Monitoring
A Discussion of New Carbon Flux Estimates and New Carbon Stock Datasets
The new carbon flux numbers show a decrease in emissions from tropical deforestation from 12-15% to roughly 10% of annual global CO2 emissions. This rate is the biggest uncertainty as to whether the natural sinks continue to be as strong as they have been. These findings do have the potential to be misinterpreted, making progress on REDD difficult. Dr. Houghton emphasizes that while the decrease does potentially show a decrease in tropical deforestation, the number is more largely driven by the rapidly rising emissions from fossil fuel use. In fact, tropical deforestation is still about 13,000,000 hectares per year.
Uncertainty in emissions rates is influenced by two things: deforestation rates and forest carbon density, or carbon stocks. The new dataset described by Dr. Baccini shows a significant increase over previous inventory-based (rather than satellite-based) estimates of aboveground carbon stocks. This new dataset, which will be released in 2011, is derived from a combination of MODIS and LIDAR data and is an innovative coupling of satellite data with co-located field measurements. This mapping activity reduces the uncertainty in the carbon stocks by capturing the variability in carbon stocks across the landscape. This allows for a more precise picture than just a national aggregate, and this will allow an opportunity for tropical countries to have access to a spatially consistent baseline.