Environmental refugees may turn out to be the biggest global health challenge presented by climate change.

Patz, Kovats (2002). Hotspots in climate change and human health. BMJ 325:1094-1098.

About 100 million people around the world live within a meter of the present-day sea level, Those 100 million people will need to go somewhere.

CSIRO Marine Research senior principal research scientist Steve Rintoul

Worse, every meter of sea level rise causes an inland recession of around 100 meters (300 feet) and more erosion occurs with every storm.

As sea level rises by up to a metre this century (the top of the forecast range), as many as 30 million Bangladeshis could become climate refugees. Many Bangladeshi families escaping floods and droughts have already slipped over the Indian border to swell the shanty towns of Delhi, Bombay and Calcutta. "The problem is hidden at the moment but it will inevitably come to the fore as climate change forces more and more people out of their homes.

an inhabited island has disappeared beneath rising seas.

Rising seas, caused by global warming, have for the first time washed an inhabited island off the face of the Earth. The obliteration of Lohachara island, in India's part of the Sundarbans where the Ganges and the Brahmaputra rivers empty into the Bay of Bengal, marks the moment when one of the most apocalyptic predictions of environmentalists and climate scientists has started coming true.

As the seas continue to swell, they will swallow whole island nations, from the Maldives to the Marshall Islands, inundate vast areas of countries from Bangladesh to Egypt, and submerge parts of scores of coastal cities.

Two-thirds of nearby populated island Ghoramara has also been permanently inundated.
Refugees from the vanished Lohachara island and the disappearing Ghoramara island have fled to Sagar, but this island has already lost 7,500 acres of land to the sea. In all, a dozen islands, home to 70,000 people, are in danger of being submerged by the rising seas.

There are at least 20 million environmental refugees worldwide, the group says—more than those displaced by war and political repression combined A12_s2_1


Urban Flooding

Thirteen of the world’s fifteen largest cities are on coastal plains. Many smaller cities, such as Alexandria, Egypt’s ancient center of learning, also face a severe risk of inundation with a 39-inch (1m) rise in sea level.

Parts of San Jose and Long Beach, California, are about three feet below sea level and New Orleans is about eight feet below sea level today.

Cities at risk cover a wide range of economic circumstances, yet many will require extensive infrastructure development to minimize the potential impacts of flooding, particularly from storm surge.

Disappearing Islands

The Majuro Atoll in the Pacific Marshall Islands is projected to lose 80% of its land with a 20-inch (0.5m) rise in sea level. Many of the islands will simply disappear under the rising seas.

A similar fate awaits other islands throughout the South Pacific and Indian Oceans, including many in the Maldives and French Polynesia.

Coral reefs, which protect many of these islands, will be submerged, subjecting the local peoples to heightened storm surges and disrupted coastal ecosystems. Tourism and local agriculture will be severely challenged.