The Heat Is Online

Florida Feels Real-Time Impacts of Climate Change

Scientists: Climate clock is ticking in South Florida


The Miami Herald, April 21, 2007


Pine trees, coral reefs, tourism and our drinking water supply are under the gun of climate change.


The warming of the planet means Florida, with 1,200 miles of heavily populated and vulnerable coastline, is feeling real-time effects that are foreshadowing bigger consequences:


" Sea levels are rising twice as fast as once predicted, eroding shorelines.


" Higher temperatures are shifting tropical conditions farther north.


" Oceans are more acidic.


" Seas are hotter.


" Droughts may be increasing, while periods of intense rainfall are farther apart.


While the long-range effects are likely to affect our grandchildren, the near-term effects are whittling away at our environment with the power of spring tides.


As evidence mounts that the earth is warming faster than once predicted, Florida is finally starting to focus on the issue. A conference May 9-11 in Tampa will look at the latest research and make recommendations to policymakers.


Those policymakers may be ready to listen.


In his recent State of the State address, Gov. Charlie Crist called climate change ``one of the most important issues that we will face this century.


'With almost 1,200 miles of coastline, and the majority of our citizens living near that coastline, Florida is more vulnerable to rising ocean levels and violent weather patterns than any other state,' he said.


At the first in a series of presentations to Florida's Cabinet, University of Florida ecologist Stephen Mulkey warned of the problems that lie ahead unless Florida reduces emissions and adapts: Cities will have to shell out big bucks for seawalls and flood-control structures; agriculture will be hurt by drought; insurance companies will refuse to provide coverage in areas vulnerable to greater storm damage; coral bleaching and acidic seas will devastate sport and commercial fishing.




Florida's exposure to danger also was noted by the scientists working on the United Nations Intergovernmental Panel on Climate Change, which has identified key areas of vulnerability.


'Florida is the only state mentioned because of the vulnerability of the coast and the infrastructure that will be exposed to more intense storms,' said Virginia Burkett, coordinator of global change science for the U.S. Geological Survey.


Whether climate change will increase the frequency or intensity of hurricanes remains controversial. Whatever the effect on storms, evidence is mounting that climate change is quickening and big changes may happen in surprising jumps.


'It's not a linear increase, but a very rapid increase in the last 20 years,' said Tom Crisman with the Patel Center for Global Solutions at the University of South Florida.


Sea levels are rising twice as fast as early computer models predicted, says Brian Soden, climate change scientist at the University of Miami's Rosenstiel School of Marine and Atmospheric Science. New calculations are estimating a three-foot rise by the end of this century, he said.


'A real concern is that the models are underestimating the rate of rise,' he said. ``If we have another decade of [satellite] records, we may have a better idea.'


The Florida Keys, tiny islands just a few feet above sea level, are the most vulnerable. Since 1930, the ocean has risen about nine inches around Key West, says Harold Wanless Jr., a geologist with the University of Miami. That island city lies an average of six feet above sea level.


'It's running right at a foot per century, and we're 75 years into it,' Wanless said.


On a barrier island, such as Miami Beach or the Florida Keys, a one-foot rise could put water 200 to 2,000 feet inland, Wanless says.

Beneath the Florida Keys, a lens of fresh water covers the salt water. As the seas rise, they push the fresh water up, especially in times of drought. As the salt water rises, the roots of trees that thrive in fresh water are then in salt water.


On Sugarloaf Key, ghostly pine stumps sit like grave markers among salt-tolerant buttonwoods, bearing witness to the insistent upward push of salt water.


Salt-sensitive pines have migrated to the highest ground on Big Pine Key, says Mike Ross, ecologist at the Southeast Environmental Research Center at Florida International University. Of the 13 different habitats in the Florida Keys, Ross says the pinelands have the greatest biodiversity, and Big Pine is the sanctuary for the dog-size Key deer.


On Florida's Gulf Coast, salty seas creeping inland are killing forest denizens in the Waccasassa Bay State Preserve Park, says Jack Putz, a University of Florida professor of forestry who measured what happened to forests from 1973 to 2003.


'The whole forest is going,' he said. ``It was quite alarming, because in the last five years, the rate at which it is dying has increased more than we predicted.'


Drainage of the Everglades in the 1960s and '70s diverted fresh water from the marshes into canals, creating a man-induced sea-level rise. Salt water moved inland and mangroves traveled with it. Now those upstream mangroves have moved farther into sawgrass. If sea-level rise reaches 23 inches by century's end, Everglades National Park expects to have 50 percent of its freshwater marshes inundated, reducing an entire ecosystem, says Dan Kimball, park superintendent.


Rising seas also threaten South Florida's underground freshwater drinking supply. If rainfall fails to replenish the underground aquifer, salt water enters the aquifer and turns fresh water brackish. As the Everglades loses its freshwater marshes to salt water, parts of the aquifer would become saline.


Saltwater intrusion into the eastern edge of Biscayne aquifer already has caused newer well fields to be moved west, says Doug Yoder, director of the Miami-Dade County Water and Sewer Department. As seas get higher, 'one expectation would be that we might have to deal with more brackish water as our water supply,' he said, raising the cost of making water fit for drinking.


Flooding, already a problem in urban South Florida, is also likely to worsen.


'If sea level goes up, [water managers] need to keep groundwater levels that much higher to keep salt water from intruding, but you get to the point where groundwaters are so high, there's no place for storm water to go,' Yoder said. ``So we would get more frequent flooding from what might now be a normal rain.'


As Florida warms up, the tropics are expanding into Central Florida, says USF's Crisman.


Temperatures in 20 Florida lakes have risen since 1970, meaning, he says, ``From mid-Lake Okeechobee south, you are in the tropics.'

That means more exotic pest plants, such as melaleucas, are moving north, as well as more insects and plant diseases.


'In North Florida, it means a longer growing season and, on the negative side, more bugs,' said Len Berry, director of the Florida Center for Environmental Studies.


And as the tropics expand, there will be demands for more electricity and air conditioning, he said.


Half of all the carbon dioxide released is being absorbed by the oceans, says Chris Langdon, a scientist at the University of Miami's Rosenstiel School who first revealed the threat to corals from ocean acidification in 2000.


That CO2 is causing oceans to become more acidic, reducing concentrations of calcium and carbonate ions used by shellfish, corals and other marine creatures to build shells.




As concentrations of CO2 in the oceans increase exponentially, Langdon expects a 50 percent to 80 percent decline in reef formation.


'I don't think they can hack it,' he said.


Threats to the coral reefs are also threats to both tourism and commercial fishing, two key Florida industries. The changing chemistry of the ocean is a double whammy for the corals, which already have suffered serious bleaching by hot seas for 15 years. Since 1996, when a reef-monitoring system was established, Florida Keys National Marine Sanctuary has declined by more than 35 percent.


'The outer reefs are most vulnerable to climate change and bleaching,' said Billy Causey, director of the sanctuary. ``In the last two decades, they have shown enormous declines.'


In some areas only 2 percent of the corals are living, while the average is less than 10 percent.




The reef system, which is a refuge for commercially important fish such as snapper and grouper, now has two important components, elkhorn and staghorn corals, on the federal threatened list, with climate change, pollution and disease topping the list of dangers.


Beginning May 9, scientists, professors and politicians will meet in Tampa for three days to look for solutions for Florida.

Crisman, co-chair of that conference, says there is a lag time between when we take action and when we get an ecosystem reaction.


'If we were to stop all air contamination now, we won't get cleaned up for decades,' he said.


'But it's not all doom and gloom,' he added. ``If I believed that, I'd shoot myself. When you take an action, a system puts down a new memory. From my perspective, [halting climate change] is about lag time, not doom and gloom.'


© 2007 Miami Herald Media Company. All Rights Reserved.