Global Warming and Ocean Environmental Changes
Climate Change Threat to Coastal Environment and Marine Biodiversity
Mar 22, 2009
The effects of global warming are beginning to be felt in the marine environment. Thermal water expansion, caused by higher global air and water temperatures are causing a gradual increase in ocean levels, while melting ice caps threaten a more serious increase. Meanwhile, rising levels of carbon dioxide in the atmosphere are causing the acidity of the ocean to increase with unknown environmental consequences for marine biodiversity.
Environmental Effects of Rising Sea Levels
Whether caused by thermal expansion due to increased temperatures or melting of ice caps, the rising sea levels threaten dire environmental consequences for the entire globe.
- Chapter 5 of Climate Change 2007: The Physical Science Basis, by the Intergovernmental Panel on Climate Change and published by Cambridge University Press in 2007 states, “Global mean sea level has been rising. From 1961 to 2003, the average rate of sea level rise was 1.8 ± 0.5 mm yr–1. For the 20th century, the average rate was 1.7 ± 0.5 mm yr–1, consistent with the TAR estimate of 1 to 2 mm yr– 1”.
- A report by the U.S. Climate Change Science Program, published in January 2009, titled “Coastal Sensitivity to Sea Level Rise: A Focus on the Mid-Atlantic Region” predicted, “Rising sea level and the potential for stronger storms pose an increasing threat to coastal cities, residential communities, infrastructure, beaches, wetlands, and ecosystems. The potential impacts to the United States extend across the entire country”.
- Chapter 4 of Avoiding Dangerous Climate Change, edited by Hans J.Schellnhuber, and published by Cambridge University Press in 2006 states, “The main causes of increased global average sea level during the 21st century are likely to be thermal expansion of the ocean, melting of small glaciers, and the melting of the Greenland and Antarctic ice sheets”.
Increasing Ocean Acidity and the Marine Environment
Rising sea levels is not the only result of climate change. Ocean acidification, caused by increased uptake of carbon dioxide by the oceans is now recognized as having a severe environmental effect on marine biodiversity.
- In the article “Ocean Acidification may Increase Calcification Rates”, published in the May 2008 edition of the Proceedings of the Royal Society B, the author, Hannah L. Wood states, “Species with calcium carbonate skeletons, such as mollusks, crustaceans and echinoderms, are particularly susceptible to ocean acidification. As pH decreases, so too does carbonate availability that has led some authors to conclude that ocean acidification will result in reduced rates of calcification and shell dissolution for all calcified organisms”.
- An article published by the Antarctic Climate & Ecosystems Cooperative Research Centre in June 2008, titled “CO2 and Climate Change: Ocean Impacts and Adaptation Issues” states, “Other ecological effects of ocean acidification may include interference in the respiration of fish, effects on larval development of marine organisms and changes in the solubility of both nutrients and toxins”.
- In Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers, published by the National Oceanic and Atmospheric Administration in June 2006, the author, Joan Kleypas states, “Species diversity in the deep ocean has been linked to surface ocean productivity (Gage and Tyler, 1991). Thus, if increased CO2 decreases calcification rates and abundance of calcifying planktonic organisms in the upper ocean, there could be cascading effects on deep sea biodiversity and ecology”.
Low lying island nation states, such as the Maldives, are already suffering from the environmental effects of rising sea levels. Adaptation to a changing climate may be a partial solution for mankind, but for marine biodiversity and the coastal environment of the planet, such adaptation is not an option. Mitigation of climate change, caused by greenhouse gas emissions, holds out the best hope to preserve these vital environmental assets.
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