Wave direction and wave power are the main climate‐related drivers of large‐scale coastal morphological hazards on open sandy coastlines. El Niño‐Southern Oscillation (ENSO) is the main climate driver affecting global wave climates on interannual timescales. Hence, a quantification of wave climate variability with ENSO would aid the characterization of coastal risk as a first‐pass assessment tool. However, no such data are available on the global scale at present. To address this, this work (1) quantifies ENSO impacts on global mean wave direction and wave power, and (2) classifies the global coast according to the ENSO wave climate hazard. The correlation coefficient (R) of the Multivariate ENSO Index between wave power and mean wave direction was calculated. Then, employing a multivariate technique, the resulting R values were used to classify the global coastlines. The results show that ENSO has distinct latitudinal impacts around the world. El Niño increases the wave power of swells generated in the extra‐tropics which propagate toward the tropics, a phenomenon which is particularly notable in the Pacific Basin, while the most significant rotations in wave direction with ENSO occur at tropical and subtropical latitudes. Based on this new information, the global coastline was classified into five distinct types, depending on the directional wave climate response to ENSO.

This paper presents a multivariate classification of the global wave climate into types driven by atmospheric circulation patterns. The primary source of the net long‐term variability is evaluated based on historical wave simulations. Results show that the monsoon, extratropical, subtropical, and polar wave climate types of the Pacific and North Atlantic Oceans are dominated by natural variability, whereas the extratropical and subtropical wave climate types in the Indian Ocean, and the tropical wave climate types of the Atlantic and Pacific Oceans exhibit a global warming signal. In the Pacific sector of the Southern Ocean, strong natural variability may mask a global warming signal that is yet to emerge as being statistically significant. In addition, wave climate teleconnections were found across the world that can provide a framework for joint strategies to achieve the goals of climate adaption for resilient coastal communities and environments.

Beach nourishment is generally seen as the preferred means of rectifying coastal erosion, due to its low environmental impact and natural evolution. The largest beach nourishment project ever carried out in Mexico took place on Cancun beach in 2006, as a response to the most intense hurricane season ever registered in Mexico, in 2005. After Hurricane Dean, in 2009, a second nourishment was conducted, which evidenced flaws in the design and execution of the first project. Previous investigations report that the need for beach re-fills directly correlates with wave energy. However, following a thorough revision of the extreme climatic events that occurred between 1978 and 2018, it has been found that the amount of erosion also depends on the frequency and duration of high energy events. The findings also show that the apparent success of the second nourishment is mainly associated with a decline in the number of extreme wave power events impacting the beach. In the conclusion to this paper, we share the knowledge gained, but not yet applied, in Mexico or elsewhere, regarding beach use, urbanization, and protection in beach planning.

Odériz, I.; Gómez, I.; Ventura, Y.; Díaz, V.; Escalante, A.; Gómez, D.T.; Bouma, T.J., and Silva, R., 2020. Understanding drivers of connectivity and resilience in coastal ecosystems experiencing tropical cyclones. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 128–132. Coconut Creek (Florida), ISSN 0749-0208.A better understanding of ecosystem connectivity and resilience is needed to establish efficient conservation strategies for coastal ecosystems. Physical maritime processes are key drivers for ecosystem connectivity in the Caribbean, where there is low wind and wave energy for most of the year but also short, extreme meteorological events. The energy peaks induced by tropical cyclones and the long calms are important for biodiversity. Climate change projections suggest that while there may be fewer tropical cyclones here, their intensity will increase. This paper analyses the effect of tropical cyclones on ecosystem resilience, studying both the potential connectivity and damage of mangrove, vegetated dune, seagrass and coral reef ecosystems at Puerto Morelos, Mexico. A numerical modelling approach was used to evaluate the spatial-temporal ecosystem connectivity and damage induced by hydrodynamic processes between 2005 and 2018, taking into account, wave, storm surge patterns and modifications in the vegetation cover following tropical cyclones. From our results, it was found that the balance of connectivity-damage to the intensity of the tropical cyclones depends on healthy ecosystems and the characteristics of geomorphology, with coral reef-seagrass-mangrove being more resilient to the increase in wave height but less resilient to the sea level rise. Open beaches with dune-mangrove was less resilient to the increases of both.