Maldives is the lowest country in the world, with maximum and average natural ground levels of only  and  above sea level, respectively. In areas where construction exists, however, this has been increased to several metres. More than 80 per cent of the country's land is composed of coral islands which rise less than one metre above sea level. As a result, the Maldives are at high risk of being submerged due to rising sea levels. The UN's environmental panel has warned that, at current rates, sea-level rise would be high enough to make the Maldives uninhabitable by 2100.