AAJ | Climate Change


Climate Change Impacts on Critical International Transportation Assets of Caribbean Small Island Developing States (SIDS): The case of Jamaica and Saint Lucia Background It is known that Jamaica faces moderate to high climate risks due to its assets as well as its people being located along the coast. The average historic temperature for the country ranges from 24 °C to 27 °C though in recent years temperature records of 33 °C – 37 °C are commonly recorded during the summer. Other trends such as the extreme precipitation and wind speeds have been observed to be increasing. Climatic Operational Thresholds This section speaks to the conditions that the airport and its staff can operate when considering the climatic changes such as increased temperatures and extreme rainfall. The standard used for identifying what are inoperative conditions in terms of temperature is NOAA’s National Weather Service’s (NWS’s) heat index as see in Figure 6.12. NOAA classifies high and very high risks as conditions that exist when temperatures are above 30.6 °C and 32.5 °C respectively combined with 80% relative humidity. Projections under the 1.5 °C SWL scenario suggest that vulnerable staff members of the NMIA could be at high risk for 5 days/year while under the SRES A1B scenario there could be an increase to 30 days/year by 2081 – 2100. Aircrafts and energy demand/costs for heating, ventilation and cooling (HVAC) systems will also be affected by the higher temperatures due to climate change. The aircraft’s lift and subsequently payloads will be reduced. To avoid loss of revenue the extension of the runway will be required. If the runway is not modified the aircrafts will have to reduce its payload a certain amount of times per year to gain the lift needed. Energy demand are expected to increase as warming increases. A generic standard of 1 °C warming was associated with a 5% increase in energy consumption. Rainfall and wind effects have however been projected to have minor impacts, outside of hurricane and storm events, as little changes have been observed from baseline periods. Temperature is therefore the main variable that is expected to affect the operative functions of NMIA.

Extreme Sea Level (ESL) and Coastal Inundation

ESL is defined here as the summation of the sea level rise (SLR), the astronomical tides and the 100-year episodic coastal water rise due to storm surges and wave set ups. It is anticipated that the 1.5 °C SWL will occur by 2033 and 2028 under the IPCC RCP 4.5 and 8.5 scenarios respectively. As such, ESL’s for this scenario are based on climatic projection for the early 2030’s as SLR is a time-lagged process and will continue long after temperatures have stabilized.

The baseline hundred year extreme sea level (ESL100) for Jamaica was estimated to be 1.96 m. When considering projections under the 1.5 °C SWL scenario for the 10, 20, 50 and 100 year event the ESL was projected to be 1.43 m, 1.60 m, 1.88 m and 2.14 m respectively. The coastal water rise is known to be the primary contributor to ESL. It is however, anticipated that the effects of this component of ESL will decrease while SLR is expected to dominate by the end of the century. This can be seen in changes between baseline and the 1.5 °C SWL scenario where SLR, the astronomical tides and the 100-year episodic coastal water rise have been estimated as about 81 %, 5.1 % and 14 % (RCP 4.5) and 89 %, 5 % and 6 % (RCP8.5), respectively. It was also noted that the return periods for the ESL will significantly decrease overtime. This was evident where the estimated baseline ESL100 of 1.96 m was projected to occur every 50 years under the 1.5 °C SWL scenario and about every 9 years by 2080 under RCP 8.5 scenario. It was also indicated that the 100 year event under the 1.5 °C SWL scenario will occur about every 6-7 years by 2100, under RCP8.5. From the results in can be concluded that higher ESL are expected to occur more frequently than previously expected.