Questioning emissions-based approaches for the definition of REDD+ deforestation baselines in high forest cover/low deforestation countries

Background REDD+ is being questioned by the particular status of High Forest/Low Deforestation countries. Indeed, the formulation of reference levels is made difficult by the confrontation of low historical deforestation records with the forest transition theory on the one hand. On the other hand, those countries might formulate incredibly high deforestation scenarios to ensure large payments even in case of inaction. Results Using a wide range of scenarios within the Guiana Shield, from methods involving basic assumptions made from past deforestation, to explicit modelling of deforestation using relevant socio-economic variables at the regional scale, we show that the most common methodologies predict huge increases in deforestation, unlikely to happen given the existing socio-economic situation. More importantly, it is unlikely that funds provided under most of these scenarios could compensate for the total cost of avoided deforestation in the region, including social and economic costs. Conclusion This study suggests that a useful and efficient international mechanism should really focus on removing the underlying political and socio-economic forces of deforestation rather than on hypothetical result-based payments estimated from very questionable reference levels. Electronic supplementary material The online version of this article (10.1186/s13021-018-0109-1) contains supplementary material, which is available to authorized users.

• Economically Rationale Baseline (ERB). This scenario was based on the ERB formulated by McKinsey & Company (2008) in the case of Guyana. Assuming that forested areas can provide higher 'value to the nation' when converted to other land uses, this report estimates the cost of avoiding the deforestation of all forested areas in Guyana, except legally protected areas. We then applied a similar hypothesis for the four territories concerned here, assuming the deforestation of all remaining forest except integrally protected areas and Indigenous territories. The ERB model was formulated as follows: is the cumulated deforestation over t0 − t, for country c, under the ERB scenario. Def ERB c corresponds to the log of the total area assumed to be deforested in country c divided by 35 (so that all available lands would be deforested between 2015 and 2050).
• Joint Research Center Proposal (JRC). The JRC scenario is based on the JRC Proposal (Mollicone et al., 2007) where carbon credits are attributed to countries involved if they manage to decrease their deforestation rates under half of global deforestation rates. Under this proposal, a distinction is made between intact and non-intact forests, but due to data constraints we were not able to make such distinction. Here we assumed a linear decrease in global deforestation rates, with two alternative scenarios where zero global deforestation is reached in 2050 (JRC2050) or 2100 (JRC2100). In our JRC scenarios, we thus assume that countries adjust their level of deforestation to half of the world average. The JRC scenario was formulated as follows: W DR 0 is the world annual initial deforestation rate. Within the present study, we chose its value according to estimates used within the Guyana-Norway agreement, corresponding to deforestation rates in developing countries only, and giving a value of 0.52% (LCDS Guyana, 2011). α is the coefficient associated with the linear decrease in world deforestation rates (reaching zero deforestation in 2050 or 2100). F C t,c corresponds to the forest cover of country c at time t in hectares.
a no-payment scenario (NPS-CI), corresponding to the two extreme crediting baselines considered within the Guyana-Norway agreement, where progressively decreasing payments were proposed if effective deforestation exceeds the FPS-CI value (corresponding to a deforestation rates of 0.056% annually), reaching value 0 for deforestation equal or higher than the threshold corresponding to the N P S C I scenario (0.1% annually). This CI scenario was formulated as follows: with Def CI t,c = CI S × F C t−1,c CI s is the rate of deforestation assumed in each scenario s (among BAU, FPS or NPS), as previously listed. F C t−1,c is the forest cover in country c at time t − 1 in hectares.

Socio-economic scenarios
Within our socio-economic scenarios, we characterized more accurately the different drivers leading to deforestation. We assumed that deforestation within the Guiana Shield was mainly driven by three factors: gold-mining, agricultural and urban expansion. Following Hammond et al. (2007), gold production in the Guiana Shield was strongly correlated with gold prices. Assuming that deforestation due to gold-mining was proportional to gold production, we calibrated a model predicting the yearly intensity of deforestation due to gold-mining based on gold-prices (Dezécache et al., 2017). Deforestation due to gold-mining was extracted from binary deforestation maps using expert-based assessment of areas impacted by gold-mining (Debarros and Joubert, 2010;Rahm et al., 2015). Deforestation not occurring within gold-mining areas was assumed to be driven by agricultural and urban expansion.
We thus formulated a model of yearly deforestation within each country composed of two independent components, a gold-mining and a demographic component.
This model was formulated as follows: with Def t,c corresponds to total predicted deforestation at year t in country c, which is the sum of predicted values of both gold-mining (Def GM t,c ) and demographic (Def Dem t,c ) components. Each component was formulated as follows: where θs are the models parameters, GoldP rice t is the yearly average international gold-price at year t, and P opCh c corresponds to yearly average predicted increase in population in country c. We created two contrasted deforestation scenarios, differing in the value of gold, while the contribution of demography remains unchanged. In the low price scenario (GM-low), gold price corresponds to the average price over 2001-2014, whereas in the high price scenario (GM-high), it doubles the maximum price over the same period, thus corresponding to a value of 3077 USD/ounce. Although the volatility of gold prices makes it impossible to provide plausible future gold prices scenarios, these assumptions aimed at proposing an average and an extremely high (given past gold prices) case studies. From these models predicting yearly deforestation, a cumulated sum was calculated.