ABSTRACT
The impact of climate change on biodiversity and ecosystem services is widely documented in the scientific literature. The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report asseverated that there is sufficient evidence of the changes in physical and biological systems already happening due to global warming (IPCC 2014), and even greater impacts on biodiversity are expected in the future (Thomas et al. 2004; Thuiller 2007). In fact, the Millennium Ecosystem Assessment report (MEA 2005) stated that climate change is expected to be the main cause for biodiversity loss and changes in ecosystem services at a global scale by the end of the twenty-first century. If global temperature rose more than 2-3°C above pre-industrial levels, 20 to 30 per cent of species will be at high risk of extinction and important changes in the structure and function of terrestrial ecosystems are very likely to occur (Fischlin et al. 2007). The changes provoked by climate change add to previous anthropogenic pressures on the ecosystems and the services they provide, such as deforestation, land-use changes, habitat loss or the overexploitation of natural resources (MEA 2005). Climate change is characterized by an increase in global average temperature
resulting in a range of changes in mean temperature and precipitation, and its extremes across continents and hemispheres. In the case of the Central American region, future scenarios indicate a general drying trend, due to an increase in temperature and a reduction of total annual rainfall (Neelin et al. 2006). This drying trend is expected to have a strong effect on water resources and hydrological ecosystem services. According to Arnell et al. (2004), the number of people living in water-stressed watersheds in Central America will significantly increase due to climate change, with over 10 million people potentially moving into water-stressed conditions (as described in Chapter 3). Runoff is foreseen to be reduced in all of the region regardless of future scenarios and potential vegetation will shift from humid to dry types, even in areas where precipitation will potentially increase, as the rise of temperature will intensify evapotranspiration reducing water availability (Imbach et al. 2012). In summary, the expected changes indicate that Mesoamerica
is a climate change hotspot among tropical regions (Giorgi 2006). In the case of Costa Rica, projections carried out by the Ministry of the Environment (Ministerio de Ambiente, Energia y Telecomunicaciones 2009) for IPPC scenario A2 show an increase in mean temperature, while annual precipitation trends varies among regions. Regarding runoff and evapotranspiration, Imbach et al. (2012) estimated a reduction of annual runoff and a likely increase of evapotranspiration by more than 20 per cent. Climate change will not only affect the physical and natural systems, but it
could also hamper socioeconomic development. This study focuses on the energy sector, which is a major component of development but also an important contributor to greenhouse gas (GHG) emissions. Nearly 64 per cent of global GHG emissions related to human activities come from the energy sector (Emberson et al. 2012). At the same time, this sector is vulnerable to the impacts of global change. Energy supply and demand, energy endowment, infrastructure, and transportation could be directly affected by climate change along with changes in economic or natural systems (Ansuategi 2014). For example, water resources are strongly linked to some energy sources, where climate change impacts on water production, availability and quality may have an effect on the energy production (Haas 2009). This is the case of the hydroelectric sector, as the amount of electricity produced is determined by the installed generation capacity, but also by the water influx to the hydropower plant (Schaeffer et al. 2012). Hydropower production is, therefore, highly dependent on climate variability and hydrologic ecosystem services, such as water quantity regulation, sediment retention and reduction of soil erosion (Kaimowitz 2004). The study presented in this chapter was conducted in Costa Rica, where major
economic sectors, such as agriculture and energy, strongly depend on water resources. The hydroelectric sector plays an important role: in 2013, the installed hydropower capacity was 1725 MW, which represents 63 per cent of the total installed capacity and 68 per cent of the total energy produced that year in Costa Rica (CEPAL 2013). The aim of this chapter is to estimate the economic value of water production
services for hydropower and to project the expected changes in hydro-energy production under different climate change scenarios in Costa Rica, by 2100. For this purpose, an innovative multidisciplinary approach is used combining biophysical, technical and economic data. The model is based on a production function relating mean annual runoff, estimated by a soil-vegetationatmosphere transfer (SVAT) model (Imbach et al. 2010), with changes in energy production for 35 hydropower plants in Costa Rica and other explanatory variables deemed to have an influence on the production of energy. Also, this methodology can be easily adapted to be applied at the regional scale taking into account the existing hydropower plants in Central America and doing the analysis by watershed unit. The conceptual framework is explained next, after which the methodology and
data used are described in detail. We then show the empirical application, and discuss results and policy implications, before presenting the main conclusions.
