Illustration of rising sea levels affecting islanders

Sea level rise

Rising sea levels are already threatening low-lying countries, as well as coastal regions

Loss of ice sheets, combined with the thermal expansion of water – the small increase in water volume caused by the rising global temperature – is leading to a global rise in sea levels.

Low-lying countries are at particular risk. The inhabitants of the Carteret Islands, part of Papua New Guinea, may be the first climate change refugees. Their land is being inundated, crops are failing and people are being moved to other islands.

Another nation at severe risk is the South Pacific nation of Kiribati, with an average elevation of just 2 metres above sea level and a population of more than 100,000.

Populations in north-western Europe may also be at risk. Countries such as the Netherlands, Germany, France, Belgium, Denmark – even Spain and Italy – will need to strengthen their coastal defences, argues the Intergovernmental Panel on Climate Change (IPCC).

Algal blooms

Algal bloom in a lake.


Dr Jennifer L Graham/US Geological Survey, eutrophication&hypoxia/Flickr

At the extreme, countries may disappear entirely. But all coastal regions will suffer more regular sea incursions, storm damage and salt-water seepage. For many, the result is likely to be a loss of life or livelihood, or displacement.

Another issue in marine environments likely to be related to climate change is the increasing prevalence of algal blooms. There has been a dramatic growth of these of microscopic life forms – and they are likely to become an increasingly significant health hazard.

Some are toxic, but they also damage the environment by consuming dissolved oxygen, creating oceanic ‘dead zones’. Their greatest impact is likely to be in marine environments, but they may also affect inland reservoirs and water supplies.

Lead image:

Illustration © Glen McBeth


About this resource

This resource was first published in ‘Health and Climate Change’ in January 2009 and reviewed and updated in September 2014.

Microbiology, Ecology and environment, Health, infection and disease
Health and Climate Change
Education levels:
14–16, 16–19, Continuing professional development