The loss of barrier islands through erosion poses a serious challenge to many communities along the Atlantic and Gulf Coasts. Along with marshes and wetlands, these islands protect coastal towns from major storms. In the past seventy years, Louisiana alone has lost almost 2,000 square miles of coastal land to hurricanes and flooding. More than 100 square miles of wetlands protecting the city of New Orleans were wiped out by a single storm, Hurricane Katrina. Due to this exposure of coastal communities, recent hurricane seasons have proven the most expensive on record: annual losses since 2005 have been estimated in the hundreds of billions of dollars. This unfortunate trend is likely to continue, since meteorological research shows that the Atlantic basin is in an active storm period that could continue for decades.
The passage describes recent hurricane seasons as the most expensive on record. Which of the following statements gives the implied reason for this increased expense?
a. Hurricane Katrina was an extremely violent storm.
b. Valuable buildings were destroyed in New Orleans.
c. The Atlantic Basin is entering an active period.
d. Destruction of barrier islands and coastal wetlands has left the mainland exposed.
D: The passage describes the loss of these coastal barrier lands to erosion. The fifth sentence then states, “the result is that recent hurricane seasons have been the most expensive on record.” This establishes the cause-and-effect between barrier island erosion and monetary losses due to great storms.