The effects of climate change in Florida are attributable to man-made increases in atmospheric carbon dioxide. Floridians are experiencing increased flooding due to sea level rise, and are concerned about the possibility of more frequent or more intense hurricanes.

The state has been described as America's "ground zero" for climate change, global warming and sea level rise, because "the majority of its population and economy is concentrated along low-elevation oceanfront."

Florida residents think climate change is happening at higher rates than the national average. As of March 2025, 88% of Floridians believe climate change is happening, with 55% believing it to be attributable to human activities. However, the state remains politically divided, with 74% of Democrats and 40% of Republicans agreeing with the scientific consensus that climate change is anthropogenic. Some communities in Florida have begun implementing climate change mitigation approaches; however, statewide initiatives have been hampered by the politicization of climate change in the United States, focusing on resilience rather than full scale mitigation and adaptation.

Since the early 1990s, sea levels in the Southeast U.S. have risen 0.12 inches (3.0 mm) per year on average. This rate is accelerating and it is projected to continue accelerating. Sea level rise is already making saltwater intrusion worse in Florida which impacts groundwater supplies. A natural phenomenon known as king tide flooding is also being exacerbated by sea level rise. This is when high tides at certain times of year are so high that they result in saltwater flooding in the absence of any precipitation. Salt water rises up through the porous limestone that Florida sits on.

A 2018 report by the Union of Concerned Scientists (UCS) found that by the year 2100, more than 1 million Florida homes would be at risk of flooding according to their high scenario projection.

A 2018 Florida International University study says that sea level rise will inundate the mangroves of the Florida Everglades. As the ocean rises, it will flood the Everglades and the Biscayne Aquifer, impacting the water supply of Miami.

Due to climate change, the range of mangroves worldwide is extending. This is due to a combination of fewer hard freezes and more intense storms. Warmer weather prevents mangroves from dying during winter months and stronger storms spread the propagules of mangroves further. However, sea level rise places certain populations of mangroves, such as those in the Everglades, at risk.

Mangroves, as well as other organisms in coastal and ocean ecosystems are referred to as blue carbon, acting as carbon sinks in the process of carbon sequestration. Carbon in blue carbon areas is stored at a faster rate than in other ecosystems, such as forests, and can remain sequestered for millions of years. The stored carbon in the mangroves of the Everglades has been estimated to be worth between $2 billion and $3.4 billion. When damaged, these ecosystems release very large amounts of carbon into the atmosphere.