Global Green USA

Climate Solutions

Sea Level Rise

Scientists warn that the biggest danger from global warming is raising sea level through a combination of increased water from glacier melting and warmer water temperatures causing expansion. Sea level has risen 4 to 10 inches this past century and is projected to rise up to 3 feet by 2100. For every foot of sea level rise we can expect about 100 feet of coastal flooding.

These sea level rises will lead to difficulties for shore-based communities in the next centuries: for example, many major cities such as London and New Orleans already need storm-surge defenses, and would need more if sea level rose. Sea level rise could also displace many shore-based populations. A study in the April, 2007 issue of Environment and Urbanization reports that 634 million people live in coastal areas within 30 feet (9.1 m) of sea level. The study also reported that about two thirds of the world's cities with over five million people are located in these low-lying coastal areas.

Today, about 25% of the world’s population lives within 62 miles (100 kilometers) of a shoreline, and this figure is likely to increase to 50% over the next twenty five years as people flock to coastal cities. As sea levels go up we can expect to see increasingly negative impacts on coastal areas. Storms will wreck a greater number of coastal properties, low-lying areas will be flooded, beaches eroded, wetland ecosystems and fish and wildlife habitats destroyed and saltwater will contaminate aquifers threatening human water supplies.

New Orleans Flooding at 1 Meter

New Orleans has already felt the impact of global warming and sea level rise. Hurricane Katrina was made much more impactful by warmer tropical sea surface temperatures, which have gone up around a half of a degree Celsius since 1970. The amount of moisture available to Katrina was increased by about 7 percent, which both fueled the storm and raised precipitation levels.

New York City Flooding at 3 Meters

San Francisco Flooding at 2.25 Meter

(Maps courtesy of Architecture 2030 - animated in partenrship with Global green,Architecture 2030, and Google)

The U.S. Environmental Protection Agency (EPA) estimates that a two foot rise in sea level would eliminate approximately 10,000 square miles of land, an area equal to the size of Massachusetts and Delaware combined. The Federal Emergency Management Agency (FEMA) estimates that about 25 percent of all buildings within 500 feet of the U.S. coastline will be taken by erosion in the next 60 years. The wild card in all this is abrupt sea level rise due to rapid melting of the Greenland ice Sheet.

SEA LEVEL RISE & THE POLES

Both the Arctic and the Antarctic are showing signs of global warming. Global Green USA, in conjunction with other Green Cross International affiliates, is bringing attention to these areas through expeditions that hilight the imminent danger caused by these warming trends. More on Pole Expeditions