Though climate change and global warming have been receiving much public attention in recent years, the interrelation between the oceans and the global climate is rarely recognized. The rainforests are often called “the lungs of the planet”, but few people realize that 70% of the oxygen we breathe comes from the seas. The Earth’s atmosphere and its oceans are entwined in a co-dependent bond.
In the coming 50 years, the Earth is expected to have temperatures and CO2 levels that are higher than those experienced in the past 500,000 years. Healthy oceans can act as a buffer for such rapid climate change; currently, oceans absorb nearly a third of all carbon emissions.In the past fifty years, the oceans have absorbed 90% of the heat caused by greenhouse gases. If this heat were to stay in the atmosphere, our ambient temperature would rise 3 °C every decade. 1
SEA LEVEL RISE
In spite of the therapeutic cooling properties of the seas, the seas cannot single-handedly hold off the massive impacts of man-induced climate change. One such effect is the rising sea levels, which create detrimental consequences for marine life and, connectedly, human beings. Thermal expansion of sea water and rapidly melting inland glaciers and continental ice sheets have been causing sea levels to rise at an accelerating rate over the past century. The most extreme warming takes place in the Antarctic Ocean, where some of the largest continental ice sheets are. The melt of Antarctic ice sheets contribute greatly to the rising sea levels.
Dr. James Hansen, the head of NASA’s Goddard Institute, predicts a sea level rise of 15 feet by the year 2100. 2 A sea level rise of even three feet would bring about 100,000,000 climate refugees and would endanger London, Bangkok, Venice, New York, and Shanghai.3 Considering the fact that more than half the world’s population lives within 37 miles of a shoreline, this puts much of the global population at risk.
Land inundation is already happening. Saline-rich seawater has already flowed 35 miles up the Mekong’s riverbanks in Vietnam’s rice-growing region and is threatening 100,000 hectares of rice.4 190 feet of coastline vanish each year in Rasheed, Egypt due to the encroachment of the sea.5 Bangladesh, often called the “ground zero of climate change”, already produces millions of climate refugees every year as the low-lying country is submerged. Sea level rise threatens 40 island nations with inundation, including the Maldives, Kiribati, and the Solomon Islands.
Rising oceanic temperatures are an inevitable byproduct of increasing levels of CO2 in the atmosphere. These warmer waters threaten the survival of coral reefs, some of Earth’s most productive and diverse ecosystems. Corals can only survive in specific water conditions and are very sensitive to react to changes in temperatures. A minimal rise or fall in water temperatures by 2-3ºC disrupts the symbiotic relationship between a coral and the algae living within its tissues. When the water temperature leaves the range suitable for coral and algae to survive in, the algae is expelled, which causes the coral to turn completely white. This phenomenon is referred to as bleaching.
Most corals can revive themselves after short-term periods of bleaching, but the bleaching process limits their growth, makes them more vulnerable to the elements, and may cause death. In 1998, 16% of the world’s coral reefs perished due to bleaching. Studies in Asia’s oceans show that levels of coral bleaching in 2010 are at the peak since the 1998 levels.6
Throughout evolution, corals have been able to adapt to environmental changes, but the rapidity and extremity of current changes present a challenge to the adaptability of coral reefs. It is likely that in the next 50 years, CO2 levels in the atmosphere will double. Some believe that even the most optimistic speculations of future CO2 concentrations spell out a disastrous future for coral reefs.
Ocean acidification, yet another problematic effect of climate change, presents a threat to coral reefs. Due increased levels of CO2 emitted into the atmosphere, the pH levels of the oceans are decreasing, and the oceans are growing increasingly acidic. This causes the calcification of species such as corals, mollusks, and crustaceans; their shells dissolve and they are inhibited them from forming new calcium carbonate. Coral reefs are the nurseries of the seas, and can shelter 1,000 species per square meter. The death of coral reefs affects food security, shoreline protection, marine biodiversity, and tourism.
Research also shows that elevated levels of CO2, acidification, and progressively warm temperatures encourage the growth of turf algae. Turf algae hinders the reproduction and growth of kelp forests, which are one of the most productive and valuable ecosystems on Earth.
HOW CAN I HELP?
While recent years have demonstrated that significant and immediate reduction of greenhouse gases is difficult, it is the only solution that attends to the root cause of climate change. While it is tempting to be defeatist and to feel that the most significant changes depend on the decisions of governmental bodies, giving up and holding an all-or-nothing mindset does not help the situation nor one’s self-respect. According to the U.S. Environmental Protection Agency, 68% of emissions are affected by national structures, such as the types of industries and large-scale agricultural methods. This may be dispiriting news, but the golden lining is that we as individuals can prevent 32% of total emissions, or about 4,800 pounds of CO2.
It is understandable that some of us may never reach a zero-emission lifestyle due to societal structures and financial constraints, but the shameful fact that Americans emit more greenhouse gases per person than any other country should rouse Americans into taking steps to individually prevent further adverse effects and minimize CO2 levels. There are plenty of resources online that suggest ways in which one can reduce one’s carbon footprint. But if you take one thing from this article, it’s this: Drive less.
The largest cause of net increase in total U.S. greenhouse gas emissions is transportation. In 2010, transportation contributed approximately 27% of total U.S. greenhouse gas emissions.7 Replace driving whenever possible with your legs, a bicycle, public transportation, or a skateboard. Each mile you do not drive prevents one pound of CO2 pollution. Habituate yourself into the massive behavior change and use transportation sources that reduce our dependence on fossil fuels.
Purkey, Sarah G., Gregory C. Johnson, 2012: Global Contraction of Antarctic Bottom Water between the 1980s and 2000s. American Meteorological Society Journals Online. Volume 25, Issue 17. September 2012.
Hansen, J.E. (2007, May 24). Scientific reticence and sea level rise. IOPScience. Retrieved January 11, 2011 from http://iopscience.iop.org/1748-9326/2/2/024002/fulltext
Gillis, J. (2010, November 13). As Glaciers Melt, Science Seeks Data on Rising Seas. The New York Times. Retrieved January 11, 2011 from http://www.nytimes.com/2010/11/14/science/earth/14ice.html?_r=3&ref=global-home
National Hydro-Meteorological Forecasting Centre (2010, March 5). VIETNAM: Record drought threatens livelihoods. IRIN. Retrieved January 11, 2011 from http://www.irinnews.org/Report.aspx?ReportId=88320
Sea level rise threatens Egypt’s Nile Delta & Alexandria. (2010, November 15). An article on Omran Frihy of the Coastal Research Institute study. Reuters. Retrieved January 11, 2011 fromhttp://www.alarabiya.net/articles/2010/11/15/126221.html
Australian Research Council (ARC) Centre of Excellence for Coral Reef Studies. 2012.
United States Environmental Protection Agency. “Climate Change and Greenhouse Gas Emissions”. http://www.epa.gov/otaq/climate/basicinfo.htm. November 2012.