Climate warming is causing sea level to rise at an increasing rate, primarily a consequence of melting polar ice caps and thermal expansion of the warming ocean. Florida sea level rise is further increased by freshwater ice melt in the arctic slowing the Gulf Stream. By 2050, sea level at St. Petersburg is projected to be over a foot higher than it is in 2020. Tidal flooding will increase in tandem, along with further saltwater intrusion into Florida’s porous limestone bedrock.

While hurricanes have always been a part of Florida’s weather, climate warming appears to be changing the behavior of hurricanes, with increasing numbers of intense hurricanes with higher wind speed and greater precipitation. Hurricane Harvey in 2017, for example, would have been a once in a hundred years precipitation event in the historical record. In today’s warming climate, destructive storms like Harvey are now a once in sixteen years event. Protecting Florida’s coastal communities will be an increasingly critical issue in the future.

Climate change is warming the atmosphere, and we know that a warmer atmosphere can hold more water: 7% more for every celsius degree of warming. That water originates as evaporation from land areas and oceans, with about 86% of evaporation occurring over the oceans and evaporation from oceans is accelerating as the oceans heat up. The result is a thirstier atmosphere absorbing rapidly evaporating water. Storms forming over warm oceans can carry a stunning quantity of water, leading to extreme rainfall as the storms move over land.

Toxic algal blooms are becoming increasingly common in Florida, a trend largely driven by nitrogen-rich fertilizer that finds its way to the ocean, accelerating algae growth. Climate warming exacerbates the problem, with extreme precipitation washing greater quantities of nitrogen into the ocean, warm water and higher levels of carbon dioxide stimulating algae growth, and sea level rise adding more shallow, warm water along the coast.

Climate warming and increasing variability influence human health in Florida directly and indirectly through temperature, humidity, precipitation, air quality and the frequency of severe storms. The frequency of extremely high air temperatures is predicted to increase, with the attendant risk of heat stroke, dehydration and cardiovascular and nervous system issues. Higher humidity will increase the heat index and the health risks still further.