## 4 Discussion  
The major discussion points that emerge from this study are framed in the context of what the results imply for the regional risk due to sea level change. _The potential usefulness of altimetry data for small island states_: Jamaica, similar to many other Caribbean nations, does not have long, continuous, and complete tide gauge records. This has proven to be a limitation for characterizing long term changes in sea level, as well as variability over seasonal to decadal timescales [16; 17]. Satellite altimetry has been used globally as a relatively accurate representation of sea level change [18]. This study corroborates the usefulness of altimetry as a reliable representation of sea level change in the region, given the reasonable correlations with selected Caribbean tide gauge data. Though there is a concerted effort to build out gauge stations across the region [81], it will take some time before records of sufficient spatial and temporal coverage exist. Altimetry records provide a useful dataset to (in the meantime) characterize aspects of sub-regional and island-specific risk due to sea level rise and on which to begin to premise planning action. _The importance of the seasonal cycle_: Though seasonal variations in rainfall and temperature have been extensively characterized for the Caribbean and individual islands, there is comparatively little documented about the seasonal cycle of sea heights at the country level [66; 76]. The EOF analyses identify the seasonal cycle as a prominent feature of the altimetry record across the entire Caribbean basin. Annual variation results from the steric response of the Caribbean Sea to heat fluxes at the surface as it warms and cools throughout the year [20; 21]. Sea levels on the Jamaican south coast are lowest in the spring months (MAM) and peak in the summer months of July-August. On average, the summer season peak is at least 7 cm higher than the boreal spring minimum. Highest sea levels occur within the hurricane season and lead peak activity by 1-2 month(s) [82; 83], exacerbating risks from storm surge and inland flooding due to strong winds associated with tropical storm events. As for climate variables, an understanding of the seasonal variation supports risk management efforts by providing bounds within which planning should occur, e.g., for constructing sea defences or determining coastal setbacks. In much the same way that knowledge of the rainfall or hurricane climatologies supports (for example) water management [84] and disaster risk reduction efforts [85], respectively, the possibility exists to better characterize the changing risk to coastal communities from sea level rise throughout the course of a year. _Increasing sea levels are a cause for alarm_: Altimetry data suggests that, for the period 1993-2019, the rate of sea level rise for Kingston, Jamaica was 3.3 \(\pm\) 0.4 mm/year when adjusted for GIA and instrumental drift. This is similar to the global mean but almost double the estimate for the Caribbean and Jamaica from prior altimetry-based studies which used 18 years or less of data available at the time they were undertaken more than a decade ago. This suggests an acceleration of the rate of sea level rise. EOF analysis shows that the increase is a feature of the entire Caribbean, though there is some spatial variability. Significantly, seasonal variability for Jamaica occurs against the background of the increasing trend such that, towards the end of the analysed period, there are years when the lowest annual sea levels (for example, over the last two years) are higher than minima recorded at the beginning of the period of analysis (for example, the first seven years). The highest maximum achieved in the seven years up to 2000 was also exceeded four times since 2015 (Figure 2b). The implication is that risk is increasing, and not only for times of the year when, climatologically, sea levels are expected to be highest.