Current and Projected Sustainability of the Water-Energy-Food Nexus in Caribbean Small Island Developing States

Within Latin American and the Caribbean (LAC), small island developing states (SIDS) of the latter are wholly reliant on their natural environments for their tourism-dependent economies yet are experiencing declining environmental health. These effects are exacerbated by Caribbean susceptibility to climate change and growing populations. With limited size, elevation, GDP, and water resources compared to Latin America, the subregion requires management and solutions tailored to the needs of each country. This study examined current and future sustainability of the Caribbean SIDS by assessing the nexus of water-energy-food (WEF) resources at the national level. In addition, the potential for nature-based solutions (NBS) was examined as a means of balancing sectors of WEF. To understand current sustainability, parameters related to water, energy, and food were compiled for 10 of the 16 SIDS of the Caribbean basin. The parameters for the water sector were compared to Falkenmark indicators, whereas energy and food sectors were compared with the LAC average for that parameter. Countries that scored below Falkenmark indicators or LAC averages across the parameters for each sector were deemed as currently unsustainable. Final classifications were tabulated for each of the SIDS to determine sectors of the WEF Nexus where they were currently failing. A geospatial analysis utilizing GIS was then conducted to determine if each SIDS retained available land for the potential of nature-based solutions for WEF Nexus failures. Data for GIS analysis included population density, slope, underlying geology, and land use/land cover. Two separate analyses were conducted, one utilizing sedimentary geology and the other employing non-sedimentary geology for countries of volcanic origin. To determine if there is sufficient available land for NBS implementation, a threshold was calculated for each country incorporating per capita requirements to treat total wastewater produced by each nation. Countries with available land greater than that of their calculated threshold were considered as able to reach sustainability for the WEF Nexus by installing NBS. Population growth and climate change effects (sea level rise and precipitation loss) were modeled for 2050 to estimate future conditions. Sea level rise (SLR) data were used as physical limitations to the installation of NBS; areas with elevations below predicted SLR were removed from available sites for NBS. Population growth and precipitation loss were used for calculating available water per capita in the year 2050 and were compared with 2020 levels. A majority of the countries examined were failing in two or more sectors of the WEF Nexus under current conditions and were thus classified as unsustainable. All countries were failing in at least one sector of the WEF Nexus, denoting subregional unsustainability in the food sector. From GIS analyses, each country was estimated to have sufficient land for potential NBS. The land area available for each country was far greater than the constructed wetland threshold for treating all wastewater for the current population. Under future conditions, this determination was not refuted, as estimated SLR did not impact available land enough to fall below constructed wetland area thresholds. Available water levels, however, were projected to be stressed by increased population and precipitation loss, resulting in three countries scoring a “fail” in the water sector where they had previously scored a “pass.” As water is a strong component of the WEF Nexus, this is highlighted as an area of focus for NBS. The current sustainability of the WEF Nexus in the Caribbean SIDS is overall failing, with future conditions intensifying these failures. However, every country has potential to implement NBS to balance the Nexus for both current and future scenarios. This analysis also works to classify the Caribbean SIDS as their own region outside of their LAC designation, as the SIDS are facing barriers that other LAC states are not generally experiencing. It is important that the Caribbean look to sustainable and effective solutions such as NBS to prevent water shortages, food inaccessibility, and energy starvation