Impacts Of Sea Level Rise On Humans
The impacts of global warming will be felt across the globe. These are a few of the many examples of the impacts of sea level rise on humans.
Flooding Bangladesh
One of the poorest nations in the world is projected to lose 17.5% of its land if sea level rises about 40 inches (1 m). Tens of thousands of people are likely to be displaced, and the country’s agricultural system will be adversely affected. Coastal flooding will threaten animals, plants, and fresh water supplies. The current danger posed by storm surges when cyclones hit Bangladesh is likely to increase.
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.
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The Majuro Atoll
If sea level rises 20 inches then 80% of the Majuro Atol will be under water. Many other islands may also be submerged if sea level rises. (Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce) |
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.
Adapting to Rising Seas
Rising sea level requires many different local responses. Urban areas on the U.S. coastline could be surrounded by rising sea water. Cities may require extensive infrastructure development to assure fresh water supplies, secure transportation, and protect people from flooding and storm surge.
Sea walls can be built to protect cities and roads from rising seas. More robust building construction may also be required to withstand the increasingly intense storms that are likely to result from global warming. Fresh water supply is a concern as sea water penetrates ground water aquifers, which become brackish and less usable further inland.
Regional Challenges
The United States could lose 10,000 square miles of dry land if sea level rises two feet (0.6m). But the impacts of rising sea level vary from one region to another. These maps identify areas along the U.S. Gulf and Atlantic Coasts that are vulnerable to a 5–10 feet (1.5–3m) rise in sea level. The U.S. Pacific Coast is far less vulnerable to coastal flooding because the land rises more abruptly from the sea.
Ecological Tradeoffs
Building sea walls is an effective way to protect roads and cities from rising sea level. Sea walls literally prevent sea water from encroaching inland and provide a buffer against storm surges.
Unfortunately, sea walls disrupt coastal ecosystems. The abrupt transition between sea water and concrete eliminates the beaches and tidal areas that support life along the coasts. This may be particularly problematic in barrier island ecosystems, such as along the southeastern coast of the United States.
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