CLIMATE CHANGE IMPACTS ON THE CARIBBEAN TRANSPORTATION INFRASTRUCTURE
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.