Executive summary:
Climate change poses special challenges for Caribbean decision makers related to the uncertainties inherent in future climate projections and the complex linkages between climate change, physical and biological systems, and socioeconomic sectors. At present, however, the Caribbean subregion lacks the adaptive capacity needed to address these challenges.
The present report assesses the economic and social impacts of climate change on the coastal and marine sector in the Caribbean until 2050. It aims both to provide Caribbean decision makers with cutting-edge information on the vulnerability to climate change of the subregion, and to facilitate the development of adaptation strategies informed by both local experience and expert knowledge.
Climate and extreme weather hazards related to the coastal and marine sector encompass the distinct but related factors of sea level rise, increasing coastal water temperatures, and tropical storms and hurricanes. Potential vulnerabilities for coastal zones include increased shoreline erosion leading to alteration of the coastline, loss of coastal wetlands, and changes in the profiles of fish and other marine life populations. The present report uses a modified version of the regional integrated model of climate and the economy (RICE model) (Nordhaus, 2010) to estimate the economic and social impacts of climate change. The RICE model views climate change in the framework of economic growth theory. The maximized economic and social welfare under the impacts of the three different climate change trajectories, shown below, are examined in the RICE model:
a) assuming there is no climate change (baseline)
b) under the A2 scenario/Business as Usual (BAU) [high impact scenario]
c) under the B2 scenario [low impact scenario]
The report considers the potential economic and social costs arising from damage to the coastal and marine sector as a consequence of tropical storms and hurricanes. The model employed assesses the impacts of tropical storm or hurricane strikes based, among other variables, on the power dissipation index (Emanuel, 2005), which computes the frequency, duration and intensity of hurricanes (Elliott, Lorde and Moore, 2012). Potential adaptation and mitigation strategies for the sector are discussed and cost-benefit analyses of selected options undertaken.
Results indicate that sea level rise would lead to the definitive loss of land each year in the Caribbean. By 2050, the area totally inundated would be just over 3,900 square kilometres under the A2/BAU climate change scenario and close to 3,500 square kilometres under B2. The value of the land lost by 2050 has been ECLAC – Project Documents collection An assessment of the economic and social impacts of climate change estimated at US$ 624 billion and US$ 406 billion, under A2/BAU and B2, respectively, accounting for between 0.6 per cent and 0.7 per cent of total land mass. Loss of land is loss of capital, with negative consequences on output. Such a loss would affect the tourism sectors in the Caribbean severely. In addition to market economic impacts (tourism and real estate), climate change in the Caribbean is predicted to have a devastating impact on marine ecosystems and natural habitats. By 2050, there would be an almost virtual collapse in coral-reef-associated ecosystems (reefs, seagrasses, reef fisheries). Those ecosystems have provided important services, from the purely recreational and biodiversity protection to breeding zones for fish, tourism attractions and natural protection from storm surges. Under A2/BAU, the value of those ecosystems would fall, to an estimated value of US$ 2.7 billion in 2050 from a high of US$ 64.7 billion in 2030; under B2, the decline would be smaller, but still very severe, falling to US$ 36.3 billion in 2050.
Grand Anse beach, St. George's, Grenada
https://en.wikipedia.org/wiki/Caribbean
Total cumulative climate damage to the coastal and marine sector increases exponentially under both A2/BAU and B2 scenarios. The cumulative value of the damage is expected to be US$ 798.7 billion by 2050 if A2 occurs, and US$ 471.7 billion if B2 occurs. Total cumulative damage to the coastal and marine sector by 2050 induced by climate change is valued at 159 per cent and 98 per cent of gross domestic product under A2/BAU and B2, respectively.
The overall decline in welfare by 2050 compared to the baseline scenario ranges from 1.2 per cent to 1.5 per cent under B2, and 2.4 per cent to 2.8 per cent under A2/BAU, depending on the discount rate. While the differences in welfare among the three scenarios appear to be relatively small, the same monetary loss would have very different consequences within countries and across the Caribbean.
The model showed that the impact of hurricanes and storms on the coastal and marine sector of the Caribbean would be high. Cumulative losses to fisheries in the subregion to 2050 would range from US$ 13.3 million to US$ 18.2 million for the worst-case scenario, and US$ 7.5 million to US$ 13.3 million for the best-case scenario. The cumulative losses to the coral reef ecosystem would be very high under a worst-case scenario, over US$ 900 million per decade in 2010, 2020 and 2030. In 2050, the cost of the potential hurricane damage would drop significantly to US$ 39.3 million, reflecting the almost complete collapse of the coral reef ecosystem by 2050. Built coastal assets would be severely damaged under both the best-case and worst-case scenarios. Predicted damage would be around US$ $ 0.5 billion in a best-case scenario and over US$ 1 billion under a worst-case scenario. These results are reinforced by existing trends, with coastal areas becoming more densely populated in response to trends in economic structure and lifestyles. Confronted with growing populations, land scarcity and infrastructural gaps, more marginal and higher-risk land is urbanized in the Caribbean every year. Moreover, land loss due to sea level rise would amplify these trends.
Net Present Value of Consumption per capita in the Caribbean under Baseline,
A2/BAU and B2 SRES Climate Change Scenarios at 1%, 2% AND 4% Discount Rates US$