Public Health and Safety

Both coastal and inland island populations and infrastructure are at risk from climate-related extreme events.  The possibility of changes in El Niño patterns or the persistence of El Niño-like conditions (as suggested by some models), could affect island populations and ecosystems in numerous ways through changes in precipitation, sea level, and tropical storm patterns.  These conditions also suggest that Atlantic hurricanes could decrease in the future because there is a relationship of reduced hurricane activity in the Atlantic following the season of starting an El Niño in the Pacific.  Nevertheless, there seems to be little change to total precipitation in the Caribbean region because rain clouds still form and rain still falls, even in the absence of hurricanes. 

Globally, sea level is projected to rise two to five times faster over the 21^st century than over the 20^th century as increased warming causes glaciers to melt and ocean waters to expand as they warm.  The US-affiliated islands would be affected by changes in sea level.  The direct affects of long-term sea-level rise include saltwater intrusion into freshwater resources or persistent flooding of low-lying infrastructure and ecosystems. Impacts from rising sea levels could also make damages from storm waves and periodic fluctuations in water levels associated with El Niño events worse. 

Environmental and Societal Impacts

With these types of projected climate changes, many stresses that islands currently face will increase.  Storms can directly damage structures, interfere with the ability to provide community services (water, fire protection, etc.), and cause deaths.  Storms can also indirectly contribute to increased disease transmission through, for example, damage to infrastructure like sanitation systems.  In American Samoa, for example, the majority of existing roads are located along the shoreline and are extremely vulnerable to damage by wind driven waves.  Without properly designed shore protection, American Samoa could lose a major portion of the shoreline, as well as the entire length of adjacent roadway to storm waves.  Both the Pacific and Caribbean regions are familiar with severe hurricanes and tropical cyclones, which have caused billions of dollars in damage from the destruction of housing, agriculture, roads and bridges, and lost tourism income. 

The unique topography of Puerto Rico and the Virgin Islands makes them susceptible to floods and landslides usually resulting from the large amounts of precipitation from tropical storms.  On most islands, much of the population, transportation and social infrastructure (for example: houses, roads, buildings, hospitals, schools), and economic activity (businesses) is located near the coast, making it potentially at risk.  Impacts from hurricane activity could be of more concern in the future because of several changes that have occurred during this century.  Population increases have put more people in the path of potential hurricane devastation.  Transportation infrastructure (roads and highways) has not kept pace with this population increase so it takes longer to evacuate people, even though hurricane-forecasting ability has improved.  Finally, the value of insured property at risk is increasing, so the ability of insurance companies to keep up with potential damage costs is diminishing. 

Severe Storms:  Hurricanes (in the Atlantic Ocean) and typhoons (in the Pacific Ocean) are among the most devastating natural disasters to society.  Hurricanes and typhoons cause billions of dollars in losses due to destruction of transportation and other infrastructure, life, and property.  Increases in population clusters, changes in age and population health, urban sprawl, insufficient roadways, and building in coastal and flood-prone areas have all increased the vulnerability of populations and the infrastructure they depend on to hurricanes and typhoons.  Removing forests has contributed to the negative impacts of severe storms by increasing the amount of runoff and erosion that result from precipitation.  Another negative affect is the increased risk of some diseases (e.g., leptospirosis and other water-borne diseases) following floods caused by even storms that are far less intense than hurricanes.  For example, tests in certain areas of Florida show that increased flow resulting from storms carries 1,000 times the normal concentration of fecal sanitary bacteria (E. coli). 

Landslides: Each year in Puerto Rico, landslides cause extensive damage to property and occasionally result in loss of life.  Although landslides can be triggered by seismic activity, for example, earthquakes, and construction on hillslopes, the leading cause of landslides in Puerto Rico is intense and/or prolonged rainfall.  Population density in Puerto Rico is high, about 1,036 people per square mile (400 people per square kilometer), and is increasing.  This increase is accompanied by the use of less desirable construction sites.  As a result, human populations are becoming more vulnerable to landslide hazards.  Human modifications of the land are also increasing the frequency of landslides.  A study conducted in Puerto Rico in 1998 found that, although average rainfall is high, intense storms are frequent, and hillslopes are steep, forested hillslopes are relatively stable as long as they are not modified by humans (e.g cut down the forests).  However, the more destruction and removal of the natural plants and trees, the more frequent are landslides. 

Economic Impacts

For American Samoa, where most of the roadways are located on the coast, each section of new or rehabilitated roadway construction must include the additional costs of sea walls, resulting in extremely expensive highway construction. 

The Caribbean's worst hurricane season since 1933 came in 1995.  Hurricanes Luis and Marilyn hit the Virgin Islands in September 1995 (see table for specific damages from Hurricane Marilyn).  Damage was greatest in St. Thomas.  Every telephone pole and 80% of the homes and businesses were destroyed.  It took eight weeks to get desalinization plants running.  Every cistern was contaminated by salt water and there was no electricity and no hand pumps to get water out of cisterns.  Essential facilities that were affected included hospitals, power and desalinization facilities, sewer systems, fire houses, police stations, public shelters, ports, communication systems, and docks.  The destruction of sewage systems lead to surface water and marine bay contamination.  The US Virgin Islands Bureau of Economic Research estimated the economic loss at $3 billion from this one storm. 

The Pacific Islands have also suffered from severe storms.  Between the years 1957 and 1995, Hawaii suffered over $2.4 billion in typhoon damages.  For the Pacific Islands, 1992 and 1997 were particularly active years.  In 1992 the US Federal Emergency Management Agency (FEMA) responded to "major disasters" in the Marshall Islands and Micronesia after Typhoon Axel struck in March; then in Guam in the aftermath of Typhoon Omar ($500 million dollars in damages).  September 1992 saw Typhoon Iniki hit the Hawaiian Island of Kauai.  It resulted in 7 deaths, approximately $1.8 billion in damages, and $259.7 million in FEMA Disaster Relief costs.  In December 1996, Typhoon Fern struck Yap and in April of 1997, Typhoon Isa struck Micronesia.  Later that year, in December, Supertyphoon Paka ($650 million in damages) pummeled Guam and the Northern Marianas, as well as the Marshall Islands causing widespread destruction. 

Strategies to Address Potential Impacts on Public Health and Safety

Strategies for improving public health and safety under changing climate conditions could include numerous options. This list is not exhaustive and should be used as a starting point.  For example:

• upgrading and protecting infrastructure (including transportation infrastructure);

• starting comprehensive disaster management (and avoidance) programs (including mapping and risk analysis);

• changing and enforcing land use policies to avoid hazards and hazardous areas;

• adopting and enforcing increasingly strong building codes;

• improving sanitation (e.g., sewage treatment systems) and health care infrastructure (e.g., hospitals);

• improving emergency plans; and

• ·increasing public and official information and outreach programs related to the range of historical disaster experiences and to future risks associated with climate change.

For potential flood conditions adaptation measures include:

• changes in land use policies that discourage construction in flood plains or areas at risk for landslides, and that allow for natural patterns of runoff, and

• improving monitoring, observation, alert, warning, and evacuation systems would also be desirable.