There are five UKOTs in this region: Anguilla, the British
Virgin Islands, the Cayman Islands, Montserrat and the Turks and
Caicos Islands.
Observed
change
According to the PRECIS project (2005), research by institutions
in Cuba and Jamaica show the following regional trends:
- The mean temperatures of individual Caribbean
territories show an upward trend over the last 30 years.
- At the end of the 1970s, significant warming
in the lower part of the atmosphere was detected in the region. The
warming supports the idea that changes are occurring in background
climate conditions. It is also consistent with significant
variations in circulation patterns that have been detected over the
North-Pacific sector of North America for the same period.
- The upward trend in the mean temperatures
seems to be largely driven by changes in the minimum
temperatures.
- The diurnal temperature range is decreasing,
consistent with global trends. From the 1950s to the present, a
two-degree change has been detected for the region.
- The number of very warm days in the region is
increasing, but the number of very cold nights is decreasing (1950s
to present).
- The frequency of droughts has increased
significantly since 1960.
A 2001 study of recent global changes in precipitation found
that conditions in the eastern Caribbean (which includes Anguilla,
the British Virgin Island and Montserrat) have been slightly drier,
while those of the northern Caribbean (which includes the Cayman
Islands and the Turks and Caicos Islands) have been wetter (New et
al., 2001 cited in Sear et al., 2001).
Projections
As with islands in the Pacific and Indian Oceans, rates of
warming in the Caribbean are expected to be lower than the global
average (IPCC, 2007). According to the Mainstreaming Adaptation to
Climate Change (MACC) Project in the Caribbean, temperature
increases are expected to be between 2.0° and 2.8°C for the 2050s
and 3.1° to 4.3°C for the 2080s. Marginal increases in rainfall are
expected, and rainfall patterns could change, but it is not yet
known how. MACC reports that sea level is expected to rise by about
38 cm between 1990 and 2080. Hurricane intensity is likely to
increase and higher temperatures could lead to a greater incidence
of vector borne diseases, such as dengue and malaria (Chen et
al., 2006).
Implications and possible future impacts
Economy: More than half the population in the Caribbean
live within 1.5 km of the coastal zone. Damage to the coastal zone
translates into damage to a considerable proportion of the
infrastructure, human settlements and industry of these countries.
There are the direct costs of repairing damage caused by storms and
other weather events, as well as the indirect costs of loss of
productivity and income forgone from badly affected industries and
sectors.
A study by the United Nations Economic Commission on Latin
America and the Caribbean (ECLAC) of the economic impact of the
2004 hurricane season in six Caribbean countries, including the
Cayman Islands, found that 76 per cent of the total impact was made
up of actual physical damage to assets (houses, businesses, roads
and bridges, utilities, schools, hospitals and clinics, etc.)
(Zapata Martí, 2005). Most of the damage affected the social
sectors (47.5 per cent). Damage and losses to infrastructure and
utilities such as electricity, water and sanitation, and transport
accounted for 15.6 per cent, and the direct environmental impact
was calculated at 1.3 per cent since most of natural resources were
expected to recuperate (Zapata Martí, 2005:42).
There are the longer-term costs of declining production in key
sectors – agriculture and fisheries and potentially tourism, as
well as the cost of loss of ecosystem services.
Higher temperatures and variability in water supplies in the
Caribbean could translate into increased transmission of dengue
fever. Drier conditions associated with El Niño events, which
seem to be getting more frequent, often give rise to the need for
water storage, which provides breeding habitats for the Aedes
aegypti mosquito that transmits dengue. Breeding habitats also
increase after heavy rains, such as tropical cyclones.
Warmer temperatures hasten the larval stage of mosquitoes, causing
them to be smaller and to need to feed more frequently. Higher
temperatures also reduce the incubation period for the parasite
that causes dengue. At 30° C, dengue type 2 has an incubation
period of 12 days, but only 7 days at 32-35° C. The projected 2°C
increased in temperature by 2080 could lead to a three-fold
increase in the rate of transmission of dengue fever in the
Caribbean (Chen et al. 2006).
Caribbean coral reefs are threatened by over fishing, disease,
pollution and run-off from agriculture, industry and human
settlements in the coastal zone. The intensity of hurricanes
is also placing stress on corals. The region’s reefs have
experienced a massive decline from approximately 50 per cent coral
cover to less than 10 per cent (Jones, 2004). Reefs are
likely to be affected by a higher incidence of bleaching and
die-out due to higher water temperatures. Additionally,
changes in ocean chemistry that are the result of higher levels of
carbon dioxide in the atmosphere are contributing to the weakening
of coral skeletons (Jones, 2004).
Across the region, mangroves are threatened by development in
the coastal zone and conversion to other uses. Mangroves are
an important element of the coastal defence system. They provide
protection against cyclones, storm surges, and tides. They are also
nurseries and habitats for many marine species and play a role in
filtering run-off from the land. Mangroves are sensitive to
the threat of sea level rise, particularly from increased
salination of the ecosystem. This sensitivity is heightened by the
pressures they are already facing.
Country impacts - Caribbean
|
Country
|
Impacts
|
|
Anguilla
|
Depletion of fish stocks.
Beach erosion, compounded by development in the coastal
zone.
A longer dry season and decreased availability of water could
affect agriculture.
Sea level rise will increase the risk of salt-water
contamination of rivers and salt-water intrusion of ground water,
which will jeopardise agricultural production in and around coastal
communities.
Increased hurricane and storm intensity could disrupt sanitation
and sewerage disposal systems as well as cause damage to coastal
communities and infrastructure.
|
|
British Virgin Islands
|
Coral reefs are vulnerable to bleaching episodes from warmer
seas and stress from hurricanes.
Low-lying Anegada is vulnerable to the effects of sea level rise
and to storm surges and wave action during hurricanes.
|
|
Cayman Islands
|
Coral bleaching
Beach erosion and destruction of turtle nesting sites.
As low-lying islands, the Cayman islands are vulnerable to the
effects of seal level rise and to storm surges and wave action
during hurricanes.
|
|
Montserrat
|
Changes in coastal vegetation.
Coral bleaching.
|
|
Turks and Caicos Islands
|
Sea level rise will increase the risk of salination of rivers
and salt-water intrusion of ground water, which will jeopardise
agricultural production in and around coastal communities.
|
For more information
Providing REgional Climates for
Impacts Studies