Placeholder Image

字幕列表 影片播放

  • 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

  • themselves and the trends change, that's climate.

  • The crisis we face was once called Global Warming".

  • And while the atmosphere and oceans are warming,

  • it's more accurate to call the phenomenon

  • "Global Climate Change".

  • Some places may get more rain and floods.

  • While other places may see more heat waves and droughts.

  • But everywhere, the waters will be rising.

  • Cape Sable is the southernmost point in the

  • United States mainland and covers the western portion

  • of Everglades National Park.

  • Scientists have been studying Cape Sable for years and

  • tracking the changes caused by climate change.

  • Since the 1930's, we have been measuring and

  • studying what's happening at Cape Sable.

  • And it is a really awesome place,

  • not only for science but to visit.

  • The scientists love Cape Sable because it is an undeveloped

  • part of Florida, which you can compare directly

  • to developed parts of Miami.

  • What we have seen happening at Cape Sable since the 1930's,

  • is sea level is rising and up to 80 times a year now,

  • high tides are pushing over the marl ridge line and salt water

  • is now pushing into what used to be a fresh water lagoon.

  • Fifty to sixty percent of land-based Everglades

  • National Park is below 3 feet in elevation.

  • This wild place where plants and animals rely on healthy

  • freshwater flow for survival is facing an inundation

  • of salt water.

  • When we think about the animals and the plants that

  • will be affected by the sea level rise along Cape Sable,

  • we're going to be thinking a lot about some of the plants that

  • are unable to migrate or move.

  • Birds, perhaps, can move somewhere else,

  • as long as they can still find habitat and food,

  • and perhaps that's saving grace for the endangered

  • Cape Sable Seaside Sparrow.

  • But there're gonna be plants that are unable to migrate

  • quicker than the sea level is rising.

  • We already see the mangroves are marching inland;

  • and that's because the sea level is rising,

  • the salt water is overtopping some of the natural barriers.

  • The mangroves are moving inland as the sea level rises.

  • If mangroves are moving in, they're obviously displacing

  • some habitat.

  • So the salt water tolerant mangroves,

  • they're displacing the fresh water habitats,

  • like the pinelands, the Cypress areas,

  • and the fresh water sawgrass prairie.

  • One thing that might slow this salt water

  • intrusion into the freshwater Everglades

  • is the implementation of Comprehensive Everglades

  • Restoration Plan, or CERP, which is a 30-year project to restore

  • a more natural water flow across central and south Florida

  • and throughout the Everglades.

  • So, there's a lot less fresh water pushing south and if we

  • can restore the flow of clean, fresh water from the north part

  • of the Everglades through Lake Okeechobee,

  • down the Florida Bay and the other southern estuaries,

  • that fresh water will actually help push back the encroachment

  • of salt water into the southern Everglades,

  • into the saw grass marshes and low-lying areas

  • of the southern Everglades.

  • So the more fresh water there is flowing south,

  • the longer the Everglades will persist as we know it.

  • Achieving the right timing,

  • quantity, quality and distribution of freshwater

  • through the Everglades is essential for the survival of

  • this national park and the flora and fauna that call the whole

  • Everglades region home.

  • The pulse of fresh water coming into the Everglades

  • for half of the year, means that the entire

  • ecosystem is dependent on the timing

  • and the quality of this fresh water.

  • If there is changes in the arrival of this fresh water

  • through the dry season or there's changes in the wet

  • season, that will have a direct impact on the environment.

  • Changes in precipita;tion patterns are projected

  • due to climate change; also predicted,

  • greater swings in the weather.

  • Highs may become higher, and lows become lower,

  • andthese extremes may last longer.

  • There may be longer periods between rain events,

  • and more intense storms when they finally arrive.

  • We are seeing things like significant cold spells that do

  • affect the wild life, the fish in Florida Bay and the fish

  • kills. We're also seeing the flip side of that,

  • warmer, excessive warm temperatures in areas,

  • we saw algal blooms and some fish kills that resulted from

  • higher than normal temperatures.

  • Rising sea levels and more extreme weather

  • events are not the only dangers;

  • warmer waters can cause widespread coral bleaching or

  • die-offs,; changes in ocean chemistry can impede coral

  • skeleton and shell development in marine life;

  • some areas will see larger and more frequent wildfires;

  • and mountains could lose their snow packs.

  • Some plants are expanding or shifting their habitat range,

  • and others are flowering earlier in the year because of warming.

  • This may lead to migrating birds arriving out of synch

  • with vital food supplies.

  • Some people point out that the earth has a history of natural

  • heating and cooling even before modern humans existed.

  • It's true that there are natural cycles;

  • but the speed at which the environment is changing is what

  • challenges the vitality and even the existence of many plant

  • and animal species.

  • It makes you think, long term,

  • about conservation strategies like land acquisition.

  • It makes you think about instead of just trying to buy all the

  • land that is important for wild life to buying corridors that

  • would allow wildlife to move from the low lying areas to the

  • highest ground.

  • And it fundamentally made us rethink everything about our

  • conservation strategies in the Florida Keys.

  • There are two approaches to dealing with the effects of

  • climate change: mitigation and adaptation.

  • Both approaches will be necessary for

  • dealing with our changing world.

  • There may be technology developed in the future

  • that could remove carbon dioxide and

  • other greenhouse gases from the atmosphere,

  • but we cannot wait for a "silver bullet".

  • We must protect and restore the natural systems that remove

  • carbon dioxide from the atmosphere and oceans.

  • Coral reefs, mangroves, marshes,

  • seagrass beds, forests and grasslands

  • all absorb carbon dioxide.

  • Conservation of these areas contributes to slowing down the

  • changes ahead and directly benefits all of us.

  • Everything's happening faster, and, you

  • know, back in 2000, I wasn't sure how much I would see

  • of global warming in my lifetime.

  • But NOW, I'm wondering if I should be living where I am

  • because I'm in beautiful Coral Gables at 11 feet above sea

  • level, far from the ocean but not far from

  • the effect of sea level rise.

  • We will see sea level rise,

  • we will have to adapt.

  • So, everybody needs to get informed about this issue and

  • make decisions today with an eye to the future.

  • Sea level rise will affect roads,

  • railroads, airports, seaports, and pipelines.

  • The cost for rebuilding will reach hundreds of billions of

  • dollars if we cannot find a way to adapt.

  • Can we be smarter when we rebuild?

  • Can we adapt our cities?

  • What can we do to our house or an apartment building so that

  • the generators aren't on the bottom floor.

  • Can we be putting more gardens on a rooftop instead of a

  • heat-absorbing black top?

  • These are engineering questions.

  • These are questions for the community

  • and for individuals.

  • For the Florida Keys, adaptation will

  • be more difficult than other places.

  • A lot of people think that the solution to sea

  • level rise is relatively straightforward.

  • They say: "Hey, just do what Holland did,

  • or do what New Orleans did, and put up a dike around the Florida

  • Keys to keep the sea out.

  • The problem with that is that sea is not only surrounding the

  • Florida Keys, it's actually under the Keys as well.

  • And the rock that our island are made of is like a Swiss cheese

  • or a sponge. It's full of holes,

  • even if you put up a dike around the islands,

  • the water would still rise from underneath our very feet

  • through that porous limestone rock that we all live on.

  • Scientists with NOAA and other agencies are collecting

  • data to quantify and assess how and where climate conditions

  • have changed.

  • This information will help predict future changes, and

  • improve climate models for regional

  • and local decision making.

  • What we're trying to do more of is to be more is to be

  • more predictive and so we are working with a lot of our other

  • scientists and collaborators to develop predictive models and

  • some other tools that help us to understand what we might be

  • faced with in the next 20 years,

  • 50 years so we can start incorporating that information

  • into our planning process.

  • Our ability to collect information to see what's

  • happening out there on the landscape at any point in time,

  • and then make appropriate changes in our management

  • strategies to address our resources in the conservation,

  • is going to be critical to insure that we can fulfill our

  • mission and really protect all these

  • great resources that we have.

  • What is happening here in south Florida is happening

  • everywhere on the planet.

  • Half the world's population lives within 60 miles of the

  • coast; just about 3 to 6 feet above sea level.

  • The most important lesson to remember is that

  • we can all make a difference.

  • One of the things the Park Service is

  • trying to do is instill the realization that it is a human

  • caused issue and climate change will have human solutions.

  • And that is where individuals have

  • the opportunity to make a difference.

  • An individual can make changes in his or her lifestyle.

  • A small step can go a long way when

  • a lot of people are doing it.

  • I think the simplest thing to do is to just to start to learn

  • about the issue; think of ways that you can act and be a part

  • of the solution.

  • A lot of people that I know are thinking about and are actively

  • trying to reduce their carbon footprint.

  • We car pool; we make decisions about what vehicles we buy;

  • we buy carbon off-sets if we go for a flight somewhere.

  • Solar panels; insulation; turning off lights when leaving

  • a room. There are hundreds of seemingly trivial ways we can

  • reduce our carbon footprint. Am I optimistic?

  • I'm optimistic when I talk to the kids.

  • I have faith.

  • Absolutely!

  • It's a human caused problem; there will be a human solution.

  • For more information on climate change and

  • how you can help do your part,

  • visit www.climate.gov, www.nature.nps.gov/climatechange

  • and http://www.epa.gov/climatechange

This week on Waterways;

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級

水路》第268集--南佛羅里達州的氣候變化和海平面上升。 (Waterways Episode 268 - Climate Change and Sea Level Rise in South Florida)

  • 121 9
    richardwang 發佈於 2021 年 01 月 14 日
影片單字