Tropical reforestation and climate change: beyond carbon, Locatelli 2015

When managed with both climate adaptation and mitigation in mind, tropical reforestation (TR) can serve multiple synergistic functions. TR mitigates regional and global climate change, not only by sequestering carbon but also through biophysical cooling (via evapotranspiration), by recycling rainfall regionally, and by reducing pressure on old growth forests.

Furthermore, TR helps local communities adapt to climate change by recharging stream flow in the dry season, reducing the severity of floods, protecting slopes against landslides and, through mangrove reforestation, reducing the impact of coastal storms and waves. Reforestation also creates livelihood opportunities through the sustainable harvest of forest products, and creates shelter and habitat for species vulnerable to climate change. However, to achieve this broad range of benefits, “reforestation practices should be designed to avoid the implementation of one strategy (mitigation or adaptation) to the detriment of the other.” Arguing for the application of what they term “climate-smart reforestation,” the authors recommend the following:

The challenge for climate-smart reforestation is to implement an effective combination of approaches to meet all three objectives: societal adaptation, climate mitigation, and ecological resilience [Locatelli 2015: 4].

However, as most policies consider the three objectives of climate-smart reforestation separately, they often overlook possible trade-offs and synergies. For example, reforestation projects managed with a carbon purpose could have detrimental consequences on water availability in the semi-arid tropics (Trabucco et al. 2008) or on biodiversity (O’Connor 2008). By contrast, reforestation that is explicitly climate-smart uses a multi-objective planning focus that enables different objectives to reinforce each other so that their interactions produce synergies rather than trade-offs. For example, tree regeneration in Tanzania under the Ngitili resource management system achieves carbon storage together with improved watershed conservation and greater provision of natural resources (water, food, and fodder) for livelihoods (Duguma et al. 2014). A proposed adaptation project in Colombia aims to reforest with flood-resistant native tree species to reduce flood impacts on downstream communities (UNDP 2012). A project in Costa Rica is testing different mixes of species and silvicultural practices to reduce vulnerability to storms and fires while also achieving carbon storage (Locatelli et al. 2011) [Locatelli 2015: 4-5].

This article underscores a key concept of this compendium – that functioning ecosystems (whether old growth or restored forests, for example) provide multiple, interwoven functions that support human and biodiverse life by regulating local, regional and global climate conditions.