Despite illustrating the key determinants of aboveground carbon
offset additionality and related monetary and environmental
benefits, the study notes that forest managers and investors in carbon
offset schemes are likely to encounter a few challenges and
limitations in implementing these findings. One major limitation
is lack of wood specific gravity values for tree species in some tropical
regions (global database on wood specific gravity, Chave et al.,
2006). Thus, some tropical forest restoration efforts may fail to
secure aboveground carbon offset additionality due to poor choice
of tree species. The situation calls for redoubling efforts to expand
the global coverage of the wood specific gravity database with a
focus on obtaining data from different tropical forests. The second
challenge is the ability of forest managers to protect the gains
made through aboveground carbon offset additionality by avoiding
sources of leakage, such as unplanned logging and conversion of
forests to other land use. Leakage remains one of the greatest challenges
to sustaining gains made through aboveground carbon offset
additionality, particularly under voluntary carbon offset
schemes (Brown et al., 2000; Fahey et al., 2010).