Chapter 3: Water
90% of the Earth's ice and 70% of fresh water is frozen in the ice of Antarctica at the South Pole, where the average ice thickness is 7,000 feet. If all Antarctica's ice melted, world-wide sea levels would rise about 200 feet, however, the temperature of most of Antarctica does not rise above freezing.
On the opposite side of the Earth at the North Pole, is the Arctic, a large floating ice mass in the Arctic Ocean, however, the arctic ice is not nearly as thick as the ice in the Antarctica. At the end of September, 2007, the Arctic sea ice dropped 39% below the average of the 1979 to 2000 period; its lowest level since 1979, when satellite measurements of the Arctic first started being made. The ice drop was so great that at end of September, 2007, the Northwest Passage, a water short cut between the Pacific and Atlantic Oceans, completely opened up for the first time in recorded history.
If global warming trends continue, then by 2030, it may happen that the Arctic Ocean will be completely ice free during the summer months, however, if the Arctic ice melts, the impact on overall sea level will be small since Arctic ice is already floating in sea water.
Nearby, but for the most part south of the Arctic, is the world's largest non-continent island, Greenland, 81% covered in ice. Because Greenland is more southernly than the Arctic, its ice is more likely to melt as global warming continues. If Greenland's ice were to completely melt, the world's sea levels would rise by about 23 feet.
Global warming causes overall air and water temperature increases due in large part to the continued increase in the human production of global warming gasses such as carbon dioxide (CO2). As ocean water temperatures rise, water expands increasing in volume and glacier ice melts both adding additional water volume to the worlds oceans, in turn, causing sea levels to rise.
In the last 100 year, sea levels have risen by 6 inches, however, glaciers are now melting at a much faster rate than they were a hundred years ago only exacerbating the sea level water rise phenomenon which is beginning to have a world wide disruptive impact. This growing global water crisis is one of humanity's greatest and complex challenges. With the strategic management and conservation of water resources being a top priority, the global human response to the impact of rising sea level on habitats and built infrastructure will be critical for their survival.
All over the world, major urban centers will be affected by rising sea level caused by global warming and climate change. Cities like New York, San Diego, Los Angeles, San Francisco, Seattle, Miami, Amsterdam, New Orleans, Buenos Aires and Venice will need to plan for the impacts associated with rising waters. Many are in fact doing so now.
As the global community begins to have an in depth understanding of the modern human relationship with water, looking at international models will be vital to developing solutions and coping strategies. Fortunately, there are organizations dedicated to advocating for these issues and getting the message out to policy makers.
Green infrastructure is an area where the issue of rising water levels can be somewhat alleviated. Through planning, implementation and community involvement places vulnerable to sea level rise can be protected. From ecological restoration to creating green cities, there are many technologies and methods that can serve as solutions to dealing with rising water.
For example, impervious surfaces such a concrete increase an urban areas vulnerability to flooding. It is important that developers, architects and engineers are aware of smart growth strategies that can be incorporated into design. In New York for example, there are new smart growth and infrastructure laws that will guide decision making in this area.
Habitat and wildlife will also be impacted as well as entire ecosystems that all life on the planet depends on for survival. Looking at water from a watershed perspective will be important when exploring sea level rise solutions. How the land is handled, managed and developed impacts not only the water quality, but the quality of life.
According to the Environmental Protection Agency, it is estimated that a one percent loss in wetlands within a watershed can increase flooding by almost seven percent. In fact, about one million gallons of water can be retained in a one acre wetland. Destruction of this natural green infrastructure can have detrimental effects in a region threatened by rising sea level.
Flooding is not only an environmental issue, it's an economic one as well, since flood damage can be expensive and, in severe cases, financially crippling for a city or community, as was seen in New Orleans after Hurricane Katrina.
Failure to first acknowledge climate-change sea-level rise, followed by failing to effectively manage water resources before sea levels rise to unprecedented levels, can result in devastating lose of life, property, and financial resources in high-flood risks regions, especially if such a region is venerable to big nature events, such as, hurricanes, typhoons, earthquakes and tsunamis are possible.
Solutions to climate-change sea-level rise related flooding, require an integrated systems approach and support from the public, private businesses, major corporations, academic institutions, first responders and government officials.