A young boy swims in a flooded area near the airport runway in Funafuti. Parts of the island flood because of ‘king tides’, which accompany very high water levels in the ocean. At this time of year the waves inundate the coastline and water also seeps up through the ground, which is made of porous coral. This natural phenomenon is particularly serious for Tuvalu, whose highest point is only a few metres above sea level. As sea levels rise, the king tides regularly flood parts of the island – a problem that is likely to increase, potentially making large areas uninhabitable