Coordination of the greenhouse gas inventory of the Guianese forest Guyane française

Context of the service

The France is composed of a metropolitan area and five overseas departments (Reunion, Guadeloupe and Martinique, Mayotte and French Guiana) as well as overseas territories - more autonomous statutes (St Pierre and Miquelon, St Martin, St Barthélémy, French Polynesia, New Caledonia, Wallis and Futuna, French Southern and Antarctic Territories, scattered islands, Clipperton). Among the countries under Kyoto commitment (known as Annex 1), France is the only country to have a very large portion of tropical forest (8 Mha in French Guiana), on which it is obliged to report its greenhouse gas (GHG) emissions/removals under the first period of the Kyoto Protocol (2008-2012).
As the exhaustive forest inventory of French Guiana had never been done, it was therefore necessary, in 2006, to quickly mobilize French scientific and technical skills in order to work on two axes: (i) Estimation of emission factors (fluxes, expressed in teCO2/ha/year), through the development of ad hoc allometric equations to estimate forest carbon stocks (above-ground and root biomass). Dead wood, litter and soil reservoirs were approximated), following different forest strata and (ii) Estimation of activity variables (changes in area, expressed in ha/year), via remote sensing of changes in forest cover.
The first axis involved the National Forestry Office (ONF), the International Centre for Agricultural Research for Development (CIRAD) and the National Centre for Scientific Research (CNRS). The second involved the Institut de recherche pour le développement (IRD), the Inventaire forestier national (IFN), the Centre national d'étude spatiale (CNES), the Centre interprofessionnel technique d'études de la pollution atmosphérique (CITEPA), the Joint Research Centre of the European Union (JRC-EU).

Services provided

The work to estimate emission factors was carried out in 2005 by the ONF and resulted in the establishment of ad hoc dendrometric data for French Guiana. The expert coordinated the second axis, both financially (setting up a round table of funders to gather the necessary budget for the purchase and processing of satellite images) and organizational (ensuring that CNES delivers the images, that the NFI processes them according to the LULUCF inventory guidelines of the Intergovernmental Panel on Climate Change (IPCC), and that CITEPA cross-references these activity variables with emission factors in order to deduce GHG fluxes from the Guianese forest).
In order to optimize the cost/accuracy ratio, it was decided to create an ad hoc methodology to monitor changes in forest cover. Instead of carrying out an exhaustive analysis of the areas ("wall-to-wall" approach), the evolution of forest cover was monitored on a stratified sample of 15,000 points, between 1990 and 2006 (test inventory), then 2008 (official inventory), using SPOT 2, 4 and 5 images of medium resolution (20-30 m). This methodology is simple, robust and well adapted to the conditions of French Guiana (lots of clouds, difficult terrain checks, scattered deforestation spots, etc.). The accuracy of the methodology was proven by the JRC, which redid the calculations with another sample and other images (Landsat) and came up with the same result. The methodology was also validated, during a control of the French GHG inventory, by auditors accredited by the Climate Convention.
In terms of results, the 2006 test inventory concluded that there was minimal deforestation in French Guiana (-0.03%/year), which had however slightly increased during the 2008 official inventory. In addition, beyond the communication of results to the Climate Convention, this work has contributed in a practical way to the progress of debates on forest carbon inventories in tropical countries, a major REDD+ issue.

Summary of the service

Coordination of greenhouse gas (GHG) inventories of Guianese forests (8 million ha): (i) Dendrometric study (foot inventories) to estimate carbon stocks and GHG fluxes of different forest strata, (ii) Geomatics study (analysis of satellite imagery) to estimate land-use changes (including deforestation), (iii) Cross-referencing of results and compilation in national GHG inventories submitted in national communications to the UNFCCC.