Countries are encouraged to identify drivers of deforestation and forest degradation in the development of national strategies and action plans for REDD+. In this letter we provide an assessment of proximate drivers of deforestation and forest degradation by synthesizing empirical data reported by countries as part of their REDD+ readiness activities, CIFOR country profiles, UNFCCC national communications and scientific literature. Based on deforestation rate and remaining forest cover 100 (sub)tropical non-Annex I countries were grouped into four forest transition phases. Driver data of 46 countries were summarized for each phase and by continent, and were used as a proxy to estimate drivers for the countries with missing data. The deforestation drivers are similar in Africa and Asia, while degradation drivers are more similar in Latin America and Asia. Commercial agriculture is the most important driver of deforestation, followed by subsistence agriculture. Timber extraction and logging drives most of the degradation, followed by fuelwood collection and charcoal production, uncontrolled fire and livestock grazing. The results reflect the most up to date and comprehensive overview of current national-level data availability on drivers, which is expected to improve over time within the frame of the UNFCCC REDD+ process.

19The interest in using Jatropha curcas L. (JCL) as a feed stock for the production of 20 bio-diesel is rapidly growing. The properties of the crop and its oil have persuaded 21 investors, policy makers and Clean Development Mechanism (CDM) project developers to 22 consider JCL as a substitute for fossil fuels to reduce greenhouse gas emissions. However, 23 JCL is still a wild plant of which basic agronomic properties are not thoroughly understood 24 and the environmental effects have not been investigated yet. Gray literature reports are 25 very optimistic on simultaneous wasteland reclamation capability and oil yields, further 26 fueling the Jatropha bio-diesel hype. In this paper, we give an overview of the currently 27 available information on the different process steps of the production process of bio-diesel 28 from JCL, being cultivation and production of seeds, extraction of the oil, conversion to 29 and the use of the bio-diesel and the by-products. Based on this collection of data and 30 information the best available practice, the shortcomings and the potential environmental 31 risks and benefits are discussed for each production step. The review concludes with a call 32 for general precaution and for science to be applied. 33 34 Keywords 35Jatropha curcas; physic nut; cultivation; bio-energy; energy conversion, bio-fuel; 36 environmental impact; greenhouse gas balance; land use impact; human health 37 2

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[1] Methane uptake by soils is a small but important flux in the global budget of atmospheric methane, and could be susceptible to changes in land use and climate. Estimates of this sink vary between 20 and 45 Tg yr À1 . We propose to develop a better constrained estimate using a mechanistic understanding of the biogeochemical controls of soil CH 4 uptake. We reviewed over 120 published papers reporting field measurements of CH 4 uptake and made over 318 annual estimates of CH 4 uptake for various types of ecosystems. We collected data from these papers for a number of parameters that are known to influence the magnitude of the sink including climatic zone, ecosystem, latitude, annual mean rainfall, annual mean temperature, and the soil texture. Regression analyses with the continuous variables (latitude, rainfall, and temperature) yielded results with poor predictive ability and no significant relationship. Stratification by class variables such as climatic zone, ecosystem type and soil texture provided better predictive ability (R 2 = 0.29, P < 0.0001). The mean largest uptake rates were observed in temperate forests with coarse soil texture, but the variance within this stratum was also large. Without any stratification, we estimate that the global soil CH 4 sink is 36 ± 23 Tg yr À1 . With stratification, the best current estimate of the global soil uptake of CH 4 is 22 ± 12 Tg yr À1 . The ecosystem type accounted for the largest part of the variation in the global data set. This inventory showed that ecosystem type, geographic zone, and soil texture strongly control CH 4 uptake. Inventory methods that take into account underlying factors that control the process provide better estimates of sink strength.Citation: Dutaur, L., and L. V. Verchot (2007), A global inventory of the soil CH 4 sink, Global Biogeochem. Cycles, 21, GB4013,