Fort Jefferson in Florida's Dry Tortugas National Park

An aerial view of Fort Jefferson in Florida's Dry Tortugas National Park. The park faces long odds of survival, as rising sea levels are poised to swallow up large parts of South Florida in the decades ahead.
Last year, nearly 275 million people grabbed their sunscreen and cameras on their way to visit one of the 370 sites managed by the National Park Service. Millions more visited historically-important places managed by NASA or state and local governments.

Those visits provide a substantial influx of tourism revenue to local communities and also give visitors insight into key moments in U.S. history, serving as powerful reminders about where we've come from.
Yet there are growing concerns about how to preserve these sites for futures generation in the face of climate change. The National Park Service estimates that at least 85 sites have already felt the impacts of climate change.

On Tuesday, a new report released by the Union of Concerned Scientists provided case studies of 25 parks and other sites threatened by climate change, particularly rising seas, increased risk of wildfires, and melting permafrost.

http://www.nps.gov/drto/planyourvisit/things2know.htm