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  • This week on Waterways;

  • Global climate change and rising sea levels in south Florida.

  • Florida's coastline beckons people from all

  • over the country, and the world.

  • A beachfront home in Florida; a vacation spot on a Key West

  • canal; a Miami waterfront condominium;

  • Being close to the water is very desirable for many people.

  • The closer to the water, the more valuable the property.

  • But Florida is disappearing.

  • Sea level rise is submerging the coastal communities of Florida,

  • and jeopardizing investments and the state economy.

  • Along with the personal and financial loss of property,

  • comes a loss of habitat and wildlife.

  • Climate change is real and is impacting the people and the

  • landscape of south Florida.

  • In the past there were some fairly dramatic

  • periods of sea level rise that caused the native

  • Americans and other indigenous people around

  • the world to rapidly and dramatically change where they

  • lived and move inland and upslope.

  • But again, for the last 3 thousand years or so,

  • the sea level has been quite stable and we have moved into

  • the shore and invested and built our homes started our businesses

  • and built all this infrastructure,

  • everything from roads to bridges and power lines and everything

  • else which makes our modern society possible.

  • But relatively recently, the trend in sea level rise has

  • been a rapid acceleration.

  • Between 1000 BC and the year 1900 sea level rose

  • about one-and-a-half inches every 100 years.

  • In Florida, in the past 100 years alone,

  • sea level has risen more than 8 inches.

  • The National Oceanic and Atmospheric Administration,

  • or "NOAA" the leading U.S.

  • agency studying climate change and sea level rise estimates

  • global sea level will rise between 8 to 80 inches by 2100.

  • The exact amount will be determined by the amount of ice

  • sheet losses and increases in ocean warming.

  • Under the worst case scenario, by the year 2100,

  • 56% of developed area in south Florida could be

  • under water at high tide.

  • Early in the morning of Monday, October 24th,

  • 2005, the people of south Florida huddled inside homes and

  • hurricane shelters, bracing themselves for the thirteenth

  • hurricane in a record-breaking storm season.

  • Hurricane Wilma had reached Category 5 strength winds,

  • but by the time it passed the Florida Keys,

  • the storm was downgraded to a category 3.

  • Wind gusts up to 120 mph wreaked havoc in the Keys,

  • but it was the flooding after the storm

  • that caused the most damage.

  • Not since Hurricane Betsy in 1965 had the Keys faced such

  • drastic flooding.

  • We got interested in sea level rise,

  • when hurricane Wilma in 2005 flooded almost the entire

  • Florida Keys with seawater.

  • And Big Pine Key, where we're now sitting was no exception.

  • In fact, my yard was under water by about 2 feet,

  • and we were able to see what and visualize what sea level rise

  • would look like, for the first time.

  • Though the eye of Hurricane Wilma passed

  • just north of the Keys,

  • sparing the island chain from the highest winds and heaviest

  • rains, the ocean surrounding the islands rose quickly,

  • inundating many island communities in two to three feet

  • of water in less than 15 minutes.

  • Coastal flooding in Key West typically occurs when water

  • levels reach 3 ft above mean sea level.

  • When storm tides for Wilma reached up to 6.5 ft above

  • sea level, almost the entire eastern

  • half of Key West was under water.

  • In 2007, Chris Bergh of The Nature Conservancy initiated a

  • research project to identify impacts of sea level

  • rise in the Florida Keys.

  • They created digital models illustrating sea level rise

  • scenarios from 7 inches to 4.6 feet to reflect the best

  • available range of sea level rise for the year 2100.

  • We got very concerned about it and we decided we should take a

  • look at the elevation of the islands in the Florida Keys and

  • then use what is called "Bathtub Modeling" to digitally using

  • computer simulations, artificially raise the elevation

  • of the ocean by different increments.

  • Since more than ninety percent of the Keys' land area is

  • less than five feet above sea level, scenario mapping

  • tools helps illustrate the potential dangers facing

  • our communities from rising sea levels.

  • The Conservancy's online mapping tool available at

  • coastalresilience.org enables web users to simulate what Big

  • Pine Key, in the middle Florida Keys,

  • would look like with a sea level rise of one to four feet,

  • or simulate a storm surge such as the one from Hurricane Wilma,

  • or a combination of both rise and surge.

  • The mapping tool uses real world elevation data,

  • along with infrastructure locations, facilities

  • like hospitals and the habitat ranges of protected species.

  • You look at South Florida or anywhere else,

  • you say, "Oh, we'll move inland."

  • Well, maybe some places you can move inland,

  • South Florida, we have the Everglades.

  • The farther inland we get, the lower it gets, so

  • we're going to lose, we're going to lose it all this century.

  • Sea level is rising because the atmosphere and the

  • ocean are warming.

  • The Earth is warming because of greenhouse gases.

  • In 1824, French mathematician and physicist,

  • Joseph Fourier, discovered that some gases trap heat within the

  • earth's atmosphere.

  • These gases, like methane and carbon dioxide,

  • are called "green-house" gases.

  • Without greenhouse gases, life on Earth would be far too cold.

  • Greenhouse gases keep the sun's

  • heat from bouncing back into space.

  • But through human activity, the amount of greenhouse gases in

  • our atmosphere has soared.

  • Through the burning of fossil fuels- such as coal,

  • oil and natural gas- approximately ten billion tons

  • of CO2 are added to the atmosphere every year.

  • However, only six to seven billion tons of CO2 are removed

  • from the atmosphere by plants and oceans.

  • More CO2 is entering the atmosphere

  • than is being removed.

  • This imbalance is the fundamental cause of our

  • accelerated climate change.

  • For more than 100 years, NOAA has been monitoring rising sea

  • levels with tidal gauges that pepper America's coastline.

  • NOAA also operates environmental satellites that perpetually

  • monitor the planet.

  • Data from these satellites is used to measure numerous

  • environmental factors including the sea surface temperature of

  • the ocean, an indicator of climate change.

  • According to NOAA data, 2012 was the warmest year ever recorded

  • in the US since record keeping began in 1895.

  • The latest climate projections call for the globe to warm

  • between 3.2°F and 7.2°F by 2100, depending on the amount of

  • future greenhouse gas emissions.

  • As the atmosphere gets hotter, ocean temperatures also

  • increase, and warmer water has a

  • greater volume than cooler water.

  • So as the ocean heats up, it gets larger,

  • and sea level rises.

  • The warming of the ocean will maybe

  • add nearly another foot this century.

  • The melting of the Alpine Glaciers,

  • which is dramatic, that may add another 8

  • or 9 inches this century.

  • But the huge potential for the sea level rise is

  • the melting of the ice sheet.

  • Greenland has enough ice, that if it all melted,

  • it could raise sea level by 23-24 feet.

  • The West Antarctic ice sheet alone has enough ice to raise

  • sea level by 25 feet.

  • While the world's ice sheets won't totally disappear

  • by the end of the century, they are

  • melting at an alarming pace.

  • Single weather events can't be directly linked

  • to climate change.

  • A study published by the Proceedings of the National

  • Academy of Sciences, estimates that for every 1.8°F increase in

  • global temperatures, there could be up to a seven-fold increase

  • in the risk of extreme storm surge events.

  • There's a common misperception about

  • differences between "climate" and "weather",

  • so weather is what's happening now.

  • Right now, it's a little bit windy and it's a little bit cool

  • and not a cloud in the sky that's the conditions

  • at the moment.

  • And "climate" is the trend over decades or centuries.

  • So, in order for me to say that the climate has changed here,

  • I would have to have these relatively windy,

  • relatively cool, relatively dry conditions for many,

  • many, many days, weeks, months, and years on end before I could

  • say that the climate is trending towards cool and dry and windy.

  • You know, one snowstorm or one hurricane or one windy day does

  • not make climate change. But when those things multiply