Abstract:
The Cancún Agreements provide strong backing for a REDDC
(Reducing Emissions from Deforestation and Forest Degradation)
mechanism whereby developed countries pay developing
ones for forest conservation1. REDDC has potential to simultaneously
deliver cost-effective climate change mitigation
and human development2–5. However, most REDDC analysis
has used coarse-scale data, overlooked important opportunity
costs to tropical forest users4,5 and failed to consider
how to best invest funds to limit leakage, that is, merely
displacing deforestation6. Here we examine these issues for
Tanzania, a REDDCcountry, by comparing district-scale carbon
losses from deforestation with the opportunity costs of carbon
conservation. Opportunity costs are estimated as rents from
both agriculture and charcoal production (the most important
proximate causes of regional forest conversion7–9). As an alternativewe
also calculate the implementation costs of alleviating
the demand for forest conversion—thereby addressing the
problem of leakage—by raising agricultural yields on existing
cropland and increasing charcoal fuel-use efficiency. The
implementation costs exceed the opportunity costs of carbon
conservation (medians of US$6.50 versus US$3.90 per Mg
CO2), so effective REDDC policies may cost more than simpler
estimates suggest. However, even if agricultural yields are
doubled, implementation is possible at the competitive price of
US$12 per Mg CO2.