Rising Sea Levels
Should we be thinking about reserving spots for our great-grandchildren on glass-bottom boat tours of New Orleans and Manhattan? How much could sea-levels rise, and when? Could it reach Ohio? University of Dayton professor Bob Brecha takes a look at the extreme possibilities of sea-level rise in the future.
Imagine a map of the United States. Think about the southeastern part of the country, from the Texas Gulf coast to Louisiana past the mouth of the Mississippi and then around the Florida peninsula. Now imagine if the ancient Greek hero, Odysseus, instead of wandering around the Mediterranean, had managed to make a voyage as far as Florida - he would have seen essentially the same coastline as today; nothing has really changed in the geography - but it is going to.
Climate change means that sea levels are rising and will rise more. The coast of the southeastern US will look drastically different. Most of Florida has an elevation less than about 100 ft. above sea level. Cities like Little Rock, Arkansas, Raleigh, North Carolina and Washington, DC are little more than 200 ft. in elevation. I mention these numbers because we know that glaciers and ice caps are melting. If all the ice were to melt - most of it is on Greenland and, especially, Antarctica, it would add about 200 ft. to the planet's oceans.
So Florida, in the distant future could become a collection of very tiny islands. The mouth of the Mississippi would move to around Memphis, Tennessee. Our descendants living in Ohio will be safe, and could still visit New Orleans, perhaps with ocean-front cafes on the upper flowers (now with water terraces) of some of the tall buildings.
I believe that people living 2500 years from now will also be part of our culture. Our actions today are on a path to radically change the world.
Of course, this could never really happen, could it? Well, there is evidence from the far past that the earth was often ice-free, but long before homo sapiens were around. In fact, it is possible to get a rough idea of how much higher than average earth temperature was at those times of ice-freeing conditions. A good estimate would be about 8 to 10 degrees Fahrenheit warmer it is now. Continuing our current path of carbon dioxide emissions could lead to a global average temperature increase of approximately that magnitude. Good-bye Florida, New Orleans and New York City.
Before looking at beachfront property in Little Rock or Raleigh, it's important to realize that the complete disappearance of earth's ice sheets would take a few thousand years - typical geological times - so many people don't worry about it. When I think back 2500 years to the time of Odysseus, I know that his adventures are part of our culture. I believe that people living 2500 years from now will also be part of our culture. Our actions today are on a path to radically change the world.
A theme running through ancient literature is that man's fate is often in the hands of the gods. In the modern world, we understand natural systems pretty well, and we have the power to prevent the worst of climate change and preserve, literally, the world as we know it.
Bob Brecha is a professor of the renewable and clean energy program at the University of Dayton.