Introduction, Definition of Terms, and Purpose Statement
The issue of rising sea levels is one of the long-lasting effects of climate change, which poses threats to coastal cities and marine ecosystems. Sea level rise is defined as the consistent increase in the average height of the oceans over the years (“Sea Level Rise”). The purpose of this report is to explore the issue of rising sea levels in the context of the World Ocean. This includes a short overview of the history, as well as an examination of the principal causes and effects of the problem.
History
Sea levels rise is a natural geographic process, which has been discerned thousands of years ago. Fletcher notes that today’s rate of the rising sea levels nearly doubled since the twentieth century, and now is the quickest over the past 2000 years (164). As highlighted in “Sea Level Rise,” similar rapid sea level rise was noticed 7000 years ago during a major climate shift. Despite a relatively stable climate now, scientists suggest that persistent human interventions, such as usage of coal since 1850, actively contribute to the changes in the water level. Due to an increased amount of CO2 in the atmosphere, sea level is approximately 20 cm higher than it used to be in 1900. With a yearly rate rising from 1.2 to 3.4 millimeters in almost 100 years, scientists predict that global sea level will grow up to one meter by the beginning of the twenty-second century (“Sea Level Rise”). Though changes in the water level occur as a part of a natural climate cycle, global warming, caused by human activity, accelerates the process.
Causes of Sea Level Rise
Environmental scientists determine three primary causes contributing to the rising sea levels. As explained by Nunez, sea levels change because of thermal expansion, melting glaciers, and “loss of Greenland and Antarctica’s ice sheets.” With global warming, the atmospheric temperature rises, heating the water, which results in it naturally expanding in volume. Higher temperatures also lead to the increased melting of mountain glaciers. Earlier, snowing in winter and spring compensated the process of ice melting during the summer, but, now, due to seasonal shifts, diminished snowfalls imbalance “runoff and ocean evaporation,” leading to sea level rise. The same tendency occurs in Greenland and Antarctica, where massive icebergs melt more rapidly because of the increased heat (Nunez). As noted by Lindsey, before the 2000s, all three factors contributed equally to the rising sea levels. Over the last two decades, however, the melting processes noticeably accelerated: ice loss in Greenland rose from 34 to 215 gigatons/year since 2002, whereas the rate of ice melting in Antarctica nearly quadrupled (Lindsey). Causes of sea level rise at certain locations may differ; yet, the scope of this report does not allow to discuss them further individually.
Effects of Sea Level Rise
Rising sea levels involve both short and long-term adverse effects for the environment. According to Nunez, higher water levels rise the risk of flooding in coastal areas. This statement is supported in “Sea Level Rise,” which suggests that before 1971, on average, US eastern coastal cities were flooded no more than five days a year. Since 2001, the rate of flooding has increased up to 20 days and continues growing (“Sea Level Rise”). Nunez also claims that sea levels rise may have negative consequences even for people living farther inland. Several examples include soil pollution with salt, erosion, and wetland flooding (Nunez). The last primary effect mentioned in “Sea Level Rise” refers to the role of rising sea levels in the formation of storm surges. Strong winds, such as hurricanes or typhoons, “push water beyond the normal high tide mark,” leading to the increased danger of flooding (“Sea Level Rise”). Threats posed by rising sea levels need to be addressed urgently to prevent further negative consequences.
Conclusion
Rising sea levels is a critical threat not only for coastal inhabitants but also for people living farther inland. Caused by thermal expansion, melting glaciers, and icebergs, sea level rise contributes to surge storms, coastal erosion, and flooding. The scope of the adverse effects addressed in this report calls for urgent actions of local and international communities, aimed at slowing down the process of global warming.
Works Cited
Fletcher, Charles. Climate Change: What the Science Tells Us. 2nd ed., John Wiley & Sons, 2018.
Lindsey, Rebecca. “Climate Change: Global Sea Level.” Climate.gov, 2018, Web.
Nunez, Christina. “Sea Level Rise, Explained.” National Geographic, 2019, Web.
“Sea Level Rise.” Smithsonian Ocean, 2018, Web.