Synthesis of remote sensing approaches for forest carbon estimation: reporting to the Kyoto Protocol

Abstract

The Kyoto Protocol requires that signatory countries reduce their human-induced emissions of CO2 by at least 5% below their emission levels of 1990 by 2008–2012. Parties ratifying the agreement are given the option to meet part of their reduction requirements through the conservation and enhancement of the carbon stored in forest ecosystems. To do this, they must estimate carbon stocks in 1990 and any changes since 1990 from all afforestation, reforestation and deforestation activities. In the UK, although some data are already available, the Protocol will require additional monitoring. To address this, we provide a quantitative assessment of remote sensing approaches for: (1) land cover discrimination to monitor deforestation; and (2) above-ground forest carbon stocks estimation. For land cover discrimination, both optical and radar remote sensing have been successful. For forest carbon stock monitoring, radar is most appropriate until LiDAR is made available from satellite platforms. While focusing on the requirements specific to the UK, our treatment is relevant for Parties having similar requirements. Finally, we stress the need for a synergetic use of approaches and for the launch of satellite missions designed especially for terrestrial carbon stock monitoring. We also highlight future requirements for improving the current forest inventory scheme.