Decision-making under uncertainty
__ Environmental policy and management decisions are complex decisions involving high levels of uncertainty. Decision makers must attempt to reconcile competing interests, a range of time scales and scientific uncertainty regarding natural processes. Structured decision-making (SDM) is one way of balancing human values, technical expertise and uncertainty for achieving better environmental policy decisions and much of the research undertaken as part of the UBC-CATIE collaboration uses SDM. More information on SDM is available at: climate-decisions.org .
The impact of climate change in Central America
__ Scaled-down climate models for predict increases in extreme precipitation events in Central America and evidence of increases in extreme precipitation events over the last 40 years are already documented (Aguilar et al. 2005, Magrin et al. 2007). High volume rainfall events can be expected to increase run-off with consequences for both soil erosion and flooding. Furthermore, periods of drought can be expected between extreme precipitation events. Changing precipitation regimes have obvious consequences for agriculture and forests and other ecosystems. Thus, climate change will increase the pressure on ecosystem services in in Mesoamerica.
Considerations for adaptation
_Climate change will affect all aspects of society and environment. Planned, anticipatory adaptation will provide for better outcomes for society. Some issues and considerations regarding adaptation in Costa Rica, and the region, are outlined below.
Costa Rica’s forests play an important role in the country’s tourism industry. The Amazon in South America and the Bosawas Biosphere Reserve in Nicaragua play important roles in climate regulation regionally and globally. These are examples of the ecosystem services that will be affected by the changes in ecosystems that result from climate change. Moreover, high rates of deforestation in the region further weaken ecosystem service provision by tropical forests. A range of diverse users at multiple scales use the ecosystem services provided by tropical forests (e.g. local inhabitants, water users, industry, tourism, carbon markets) and reductions in ecosystem service provision have the potential to cause conflict. A responsive governance system is required in order to balance local, national, regional and even global interests in tropical forests in order to ensure beneficial outcomes in both human and environmental terms.
Subsistence and export-oriented agriculture play a significant role in the economies of many Latin American countries. Changing precipitation patterns (i.e. extreme rainfall events interspersed with periods of drought) can be expected to affect production systems and yields. It is thus important to identify and implement mechanisms that build resilience among small, medium and large agricultural producers. Extreme rainfall can be expected to increase soil erosion rates. This is of particular concern in areas, such as a Birris watershed, where export-oriented vegetable production occurs on steep slopes with fertile and abundant (but eroding) volcanic soils. In this case, mechanisms for enhancing soil retention services (SRS) are a key adaptive measure. Drought and other consequences of changing precipitation patterns, like the non-recharge of aquifers, will also be of concern in other agricultural regions and for other crops (like pineapple).
Many countries in the region have important hydroelectric generating capacity and national energy policies are increasingly focusing on renewable energy sources (including increasing hydroelectric capacity). Heightened variations in river flow patterns resulting from changing precipitation regimes and climate change may lead governments to invest in reservoir-based facilities and not run-of-river projects, with important consequences for local populations and aquatic ecosystems. Upstream erosion (which is expected to increase under climate change) may affect operating costs of hydro-electric facilities, highlighting the importance of ensuring upstream soil retention services in climate change adaptation.