Rising Sea Levels: Environmental Impact

One of the most discussed effects of global warming is the increased rate of sea level rise. The rise is due primarily to higher temperatures, which effect sea levels in two ways. First, if temperatures rise, water gets hotter, causing it to expand. Second, the heat melts ice sheets, caps, and glaciers, causing meltwater to flow into the oceans. In a previous article, I discussed the impact of sea level rise on humans; in this article, I will discuss the impact on the environment.

Coastal wetlands are key ecosystems in the biosphere. They support a combination of oceanic species and land species- everything from seagulls to striped bass. They form a “transition zone”, where salt and freshwater fish species like the trout can pass from rivers and streams to the sea. However, rising sea levels are threatening these key habitats. As ocean levels rise, erosion occurs on the shore. As wetlands depend on solid ground for cattails and other aquatic plants to grow, the removal of earth can be devastating. Researchers suggest that by 2080 almost 33% of wetlands will be converted into open water.

Most aquatic animal and plant species are highly sensitive to salinity levels in their water. As sea levels rise, they flood low-lying freshwater marshes and lakes, making them partially saline. This can kill and damage many native species. The Florida Everglades, for example, are in danger of become salty due to the encroachment of the Atlantic ocean. This would devastate the rich plant and animal life of the Everglades.

Rising sea levels increase the intensity of storms and floods throughout the world. In high-risk areas like Southeast Asia and Australia, floods could decimate much of the inland plant and animal population. Most ground and burrowing animals, for example, could drown in their dens. Australian researchers have modeled the effects of floods in the future and have discovered that, with the current rate of sea level rise, a storm that now floods 32 square kilometers will flood 71 square kilometers by 2050.

So even though sea levels rise only a few millimeters per year, they can have disastrous effects on world ecosystems. It shows just how sensitive nature is- the smallest change can make a world of difference.

http://www.smh.com.au/news/environment/effects-of-sealevel-rise-only-just-beginning/2007/10/02/1191091115328.html

http://www.epa.gov/climatechange/effects/coastal/index.html

http://environment.about.com/od/greenhouseeffect/a/rising_sea_leve.htm