Figure 6C.1: Billions of dollars of coastal infrastructure has
been built immediately adjacent to the coast, as shown here in
Gold Coast, Australia.
Photo: Bruce Miller
Figure 6C.2: Low-lying coral
atolls are particularly vulner-
able to sea-level rise.
Photo: John Hay
contributes to coastal erosion and inundation of low-lying Sea-level rise is a central element in detecting, under-
coastal regions – particularly during extreme sea-level events standing, attributing and correctly projecting climate
– and saltwater intrusion into aquifers, deltas and estuaries. change. During the 20th century, the oceans have stored
These changes have impacts on coastal ecosystems, water well over 80 per cent of the heat that has warmed the
resources, and human settlements and activities. Regions at earth. The associated thermal expansion of the oceans,
most risk include heavily populated deltaic regions, small is- together with changes in glaciers and ice caps, will likely
lands, especially atolls (islands formed of coral, Figure 6C.2), dominate 21st century sea-level rise. However, on longer
and sandy coasts backed by major coastal developments. time scales, the ice sheets of Greenland and Antarctica
CHAPTER CHAPTER 6C6C ICE AND SEA-LEVEL CHANGE 155