Climate change threatens public health, safety, economy along U.S. coasts

The report’s authors noted that the population of the coastal watershed counties of the United States and territories, including the Great Lakes, makes up more than 50 percent of the nation’s population and contributed more than $8.3 trillion to the 2011 U.S. economy, but depends on healthy coastal landforms, water resources, estuaries, and other natural resources to sustain them. Climate changes, combined with human development activities, reduce the ability of coasts to provide numerous benefits, including food, clean water, jobs, recreation, and protection of communities against storms.

Seventy-nine federal, academic and other scientists, including the lead authors from the NOAA and USGS, authored the report which is being used as a technical input to the third National Climate Assessment — an interagency report produced for Congress once every four years to summarize the science and impacts of climate change on the United States.

Other key findings of the report include:

• Expected public health impacts include a decline in seafood quality, shifts in disease patterns and increases in rates of heat-related morbidity.
• Changes in the location and the time of year when storms form can lead to large changes in where storms land and the impacts of storms. Any sea-level rise is virtually certain to exacerbate storm-surge and flooding related hazards.
• Because of changes in the hydrological cycle due to warming, precipitation events (rain, snow) will likely be heavier. Combined with sea-level rise and storm surge, this will increase flooding severity in some coastal areas, particularly in the Northeast.
• Temperature is primarily driving environmental change in the Alaskan coastal zone. Sea ice and permafrost make northern regions particularly susceptible to temperature change. For example, an increase of two degrees Celsius during the summer could basically transform much of Alaska from frozen to unfrozen, with extensive implications.
• As the physical environment changes, the range of a particular ecosystem will expand, contract or migrate in response. The combined influence of many stresses can cause unexpected ecological changes if species, populations or ecosystems are pushed beyond a tipping point.
• Although adaptation planning activities in the coastal zone are increasing, they generally occur in an ad-hoc manner and are slow to be implemented. Efficiency of adaptation can be improved through more accurate and timely scientific information, tools, and resources, and by integrating adaptation plans into overall land use planning as well as ocean and coastal management.
• An integrated scientific program will reduce uncertainty about the best ways coastal communities can to respond to sea-level rise and other kinds of coastal change. This, in turn, will allow communities to better assess their vulnerability and to identify and implement appropriate adaptation and preparedness options.

— Read more in Coastal Impacts, Adaptation, and Vulnerabilities: a technical input to the 2013 National Climate Assessment