Global climate change is expected to cause rising temperatures, higher sea level, and more powerful storms. The rates of global climate change are expected to be much greater in the next century than they have been in the past.
Rising sea temperatures will impact fisheries and aquaculture that provide food to a great percentage of the human population, particularly in coastal developing countries. Elevated sea temperatures will likely change the geographical range of harmful algal species and autochthonous pathogens. For example, V. vulnificus is known to proliferate in warm coastal waters of the Gulf of Mexico. If there is widespread warming in the Gulf, the concentration of V. vulnificus might increase, assuming other factors are not limiting. Warming of waters outside of the Gulf could lead to an increase in the geographic range of V. vulnificus presenting risks to more individuals.
Rising sea level will change the location of the shoreline and the range of coastal flooding. Existing sewage infrastructures may be inundated by seawater that could increase the amount of sewer leaks and pathogen inputs to coastal waters. Rising sea level could cause salinization of surface and groundwater drinking water sources, particularly in developing countries, and adversely affect human health.
Rainfall associated with coastal storms will increase land-based runoff to the ocean. Runoff can contain high levels of nutrients that can fuel algal blooms, and high concentrations of transient pathogens. High rainfall can overwhelm sewage infrastructure and cause sewer overflows, which can also lead to increased pathogen and nutrient inputs into the ocean.