Scenarios of rainfall and temperature changes for the period 2071–2100 under the A2 and B2 Special Report on Emissions scenarios are examined using the Hadley Centre Providing Regional Climates for Impacts Studies regional climate model. The model simulates ‘present‐day’ (1979–1990) rainfall and temperature climatologies reasonably well, capturing the characteristic bimodality of Caribbean rainfall and the boreal summer maximum and winter minimum temperatures. Seasonal spatial patterns are also reproduced, but rainfall amounts are underestimated over the northern Caribbean island masses, including Cuba, Jamaica, Hispaniola and Puerto Rico. Temperatures over the region are also overestimated by 1–3 °C. For the period 2071–2100, temperatures are projected to increase across the region by 1–4 °C for all months irrespective of the scenario. The rainfall response varies with season with one of the more robust changes being an intensification of a gradient pattern in November–January, in which the northern Caribbean (i.e. north of 22°N) gets wetter and the southern Caribbean gets drier. There is also a robust June–October drying signal. The results point to changes in the regional circulation patterns due to the human‐induced climate change and warrants further investigation. Copyright © 2010 Royal Meteorological Society

The Caribbean Low Level Jet (CLLJ) is shown to be a real and dominant climatological feature of the early summer Caribbean climate. It manifests as an intensification in the trade winds in the western Caribbean basin (70°W–80°W) with an east‐west axis along 15°N. It is confined to heights below 600 mb and has maximum wind speeds approaching 16 m/s near the surface. The study shows that there is variability in the strength and zonal extent of the CLLJ which can be related to zonal SST gradients between the eastern equatorial Pacific and the north tropical and/or equatorial Atlantic. When the gradient is driven by the Pacific (as in an EL Niño event) the CLLJ winds are intensified to the north and in its southwesternmost quadrant. When the winds are driven by the tropical north Atlantic there is uniform wind intensification about the jet axis. The CLLJ is also linked to a precipitation maximum over the near waters and along the Caribbean coast of Central America (up to 16°N) during June and more so, in July. There is evidence of variation at the northern extent of this wet zone depending on the ocean basin forcing the SST gradient. The CLLJ is also linked to moderate drying in the main Caribbean basin. Copyright © 2007 Royal Meteorological Society

Observed and projected changes in climate have serious socio-economic implications for the Caribbean islands. This article attempts to present basic climate change information-based on previous studies, available observations and climate model simulations-at spatial scales relevant for islands in the Caribbean. We use the General Circulation Model (GCM) data included in the Coupled Model Intercomparison Project phase 3 (CMIP3) and the UK Hadley Centre regional climate model (RCM) data to provide both present-day and scenario-based future information on precipitation and temperature for individual island states. Gridded station observations and satellite data are used to study 20th century climate and to assess the performance of climate models. With main focus on precipitation, we also discuss factors such as sea surface temperature, sea level pressure and winds that affect seasonal variations in precipitation. The CMIP3 ensemble mean and the RCM successfully capture the large-scale atmospheric circulation features in the region, but show difficulty in capturing the characteristic bimodal seasonal cycle of precipitation. Future drying during the wet season in this region under climate change scenarios has been noted in previous studies, but the magnitude of change is highly uncertain in both GCM and RCM simulations. The projected decrease is more prominent in the early wet season erasing the mid-summer drought feature in the western Caribbean. The RCM simulations show improvements over the GCM mainly due to better representation of landmass, but its performance is critically dependent on the driving GCM. This study highlights the need for high-resolution observations and ensemble of climate model simulations to fully understand climate change and its impacts on small islands in the Caribbean

A 10-member ensemble from phase 5 of the Coupled Model Intercomparison Project (CMIP5) is used to analyze the Caribbean’s future climate when mean global surface air temperatures are 1.5°, 2.0°, and 2.5°C above preindustrial (1861–1900) values. The global warming targets are attained by the 2030s, 2050s, and 2070s respectively for RCP4.5. The Caribbean on average exhibits smaller mean surface air temperature increases than the globe, although there are parts of the region that are always warmer than the global warming targets. In comparison to the present (using a 1971–2000 baseline), the Caribbean domain is 0.5° to 1.5°C warmer at the 1.5°C target, 5%–10% wetter except for the northeast and southeast Caribbean, which are drier, and experiences increases in annual warm spells of more than 100 days. At the 2.0°C target, there is additional warming by 0.2°–1.0°C, a further extension of warm spells by up to 70 days, a shift to a predominantly drier region (5%–15% less than present day), and a greater occurrence of droughts. The climate patterns at 2.5°C indicate an intensification of the changes seen at 2.0°C. The shift in the rainfall pattern between 1.5°C (wet) and 2.0°C (dry) for parts of the domain has implications for regional adaptation pursuits. The results provide some justification for the lobby by the Caribbean Community and Small Island Developing States to limit global warming to 1.5°C above preindustrial levels, as embodied in the slogan “1.5 to Stay Alive.”

There is an urgent need to mitigate climate change-induced heat stress in livestock and poultry in the Caribbean, given the deleterious effects it has on food and nutrition security. The temperature humidity index (THI) was used to assess the potential for heat stress on four types of livestock and poultry (broiler and layer chickens, pigs and ruminants) for three different agro-ecological locations in Jamaica. The THI was formulated specifically to each livestock type and was examined for 2001–2012 for seasonal and annual patterns of variability. Differences in THI were observed between summer (July to September) and winter (December to February) with some moderation due to agro-ecological location. Our results suggest that animals in ambient field conditions in Jamaica may already be experiencing considerable periods of heat stress even during the relatively cooler northern hemisphere winter months. Future patterns of heat stress relative to a 1961–1990 baseline were derived from a regional climate model when mean global surface air temperature is 1.5, 2.0 and 2.5 °C above pre-industrial levels. At 1.5 °C, marked increases were noted in THI and almost persistent year-round heat stress is projected for Caribbean livestock. Conditions will be exacerbated at the higher global warming states. Possible response strategies such as cooling technologies are discussed.

Under global warming the Caribbean is projected to be significantly drier by century's end during its primary rainy season from May to November. The PRECIS regional model is used to simulate the end‐of‐century (2071–2100) manifestation of the Caribbean Low Level Jet (CLLJ) under two Intergovernmental Panel on Climate Change (IPCC) global warming scenarios. The CLLJ is a feature of the Intra‐American seas which during its July peak is dynamically linked to a brief mid‐summer drying and interruption of the Caribbean rainy season. The regional model captures the CLLJ's present‐day spatial and temporal characteristics reasonably well, simulating both the boreal winter (February) and summer (July) peaks. Under global warming there is an intensification of the CLLJ's core strength from May through November. The intensification is such that by October the CLLJ is of comparable core strength to its present‐day peak in July. The persistence of the strong CLLJ beyond July and through November is linked to the perpetuation of a dry pattern in the Caribbean in the future. In contrast, the boreal winter manifestation of the CLLJ is largely unaltered in the future. Copyright © 2012 Royal Meteorological Society