Rising sea level will have important consequences for people living in the coastal zone.
Sea level is rising due to global warming. Sea levels are rising by about 2mm per year (and by about 20cm over the century). It’s predicted to rise by between 18-59cm by 2100.
Global warming has two effects that cause sea levels to rise:
- Melting ice: the melting of ice on land (e.g. Antarctica) causes water that’s stored as ice to return to the oceans. This increases the volume of water in the oceans and causes sea levels to rise.
- Heating oceans: increased global temperatuers cause the oceans to get warmer and expand (thermal expansion). This increases the volume of water causing sea level to rise.
Case study – The Maldives
Coastal flooding in the Maldives – video
Which country will be underwater in our lifetime? video
- Maldives is a group of islands in the Indian Ocean
- 1190 islands of which 199 are inhabited
- Average island height is around 1.5m above sea level but 80% of the land is below 1m.
- Population of around 300,00 people
- Because of rising sea levels scientists predict the islands will be completely submerged within 50 to 100 years.
- Coastal flooding has a variety of impacts on the Maldives.
Economic Social Political Environmental
- Loss of tourism – tourism is the largest industry in the Maldives. if the main airport can’t function properly because of coastal flooding the country will be cut off from international tourists. This will massively reduce the country’s income.
- Disrupted fishing industry – fish are the Maldives largest export. Coastal flooding may damage fish processing plants, reducing the fish exports and the country’s income.
- Houses are damaged or destroyed – a severe flood could make whole communities homeless.
- Less freshwater available – supplies of freshwater are already low on the islands. If supplies are polluted with salt water during floods then some islands will have to rely on rainwater or expensive desalination plants to meet their water needs.
- The Maldivian government had to ask the Japanese government to give them $60 million to build the 3m high sea wall which protects the capital city, Malé .
- Changes to environmental policies – the Maldives has pledged to become carbon neutral so it doesn’t contribute to global warming. The Maldivian government is encouraging other governments to do the same.
- Changes to long-term plans – the government is thinking about buying land in other countries such as India and Australia so they can move Maldivians there before the islands become uninhabitable.
- Loss of beaches – coastal flooding erodes beaches at a rapid rate. This destroys habitats and exposes the land behind to the effects of flooding.
- Loss of soil – the soil on most of the islands is shallow (about 20cm deep or less). Coastal floods could easily wash the soil layer away which means that most plants won’t be able to grow.