Greenhouse Effect, Sea Level Rise, and Coastal Drainage Systems

Abstract

Increasing concentrations of carbon dioxide and other gases are expected to warm the earth several degrees in the next century, which would raise sea level a few feet and alter precipitation patterns. Both of these changes would have major impacts on the operation of coastal drainage systems. However, because sea level rise and climate change resulting from the greenhouse effect are still uncertain, most planners and engineers are ignoring the potential implications. Case studies of the potential impact on watersheds in Charleston, South Carolina, and Fort Walton Beach, Florida, suggest that the cost of designing a new system to accommodate a rise in sea level will sometimes be small compared with the retrofit cost that may ultimately be necessary if new systems are not designed for a rise. Rather than ignore the greenhouse effect until its consequences are firmly established, engineers and planners should evaluate whether it would be worthwhile to insure that new systems are not vulnerable to the risks of climate change and sea level rise.

Controls on soil cellulose decomposition along a salinity gradient in a Phragmites australis wetland in Denmark

“…These systems, however, are being perturbed by a myriad of anthropogenic activities including hydrologic modification, dredge and fill activities, grazing and harvesting, nutrient runoff, and pollutant input (Williams, 1993;Viles and Spencer, 1995). In addition, the predicted effects of global warming in accelerating sea level rise are likely to further impact coastal wetlands by promoting salinity intrusion and submergence (Titus, 1988).…”

Greenhouse effect, sea level rise, and barrier Islands: Case study of long beach Island, New Jersey

“…Park, et al (1986Park, et al ( , 1989 used topographic maps and remote sensing and estimated that a two-to seven-foot rise in sea level would result in a 50-90 percent loss of U.S. wetlands. We have argued elsewhere that adverse environmental impacts could be diminished significantly if the area inland of the wetlands are abandoned to enable ecosystems to migrate landward (Titus 1984(Titus , 1986(Titus , 1988.…”

“…Flooding would increase both because storm surges would have higher bases to build upon (Kana et al 1984;Leatherman 1984) and because rainwater would drain more slowly (Titus et al 1987). Finally, the salinity of estuaries and aquifers would increase, threatening water supplies and aquatic life.…”

“…Those that intend to employ levee systems have little reason to do anything today toward erecting a system that will not be necessary for fifty years. Because beach nourishment can be employed incrementally, there is no reason to begin placing sand on beaches that are not yet eroding, although some consideration may be worthwhile during the routine reconstruction of drainage systems (Titus et al 1987) and roads.…”

Assessing the consequences of sea level rise: effects of changes in the slope of the substratum on sessile assemblages of rocky seashores

“…In particular, organisms are expected to shift their upper limits of distribution higher up the shore, where they will face new habitats that may or may not be suitable for colonization (Oertel et al 1992, Bird 1993, Bijlsma 1997. Such shifts in distribution could be hindered by human interventions like the construction of bulkheads, breakwaters and installations aimed at reducing sedimentation, or by natural changes in the morphology of the coast (Titus 1988). The physical aspect of the substratum would change considerably for shores that are nearly flat at their seaward end and become steeper towards the landward end, a characteristic of many rocky coasts around the world.…”