When It Comes to Sea-Level Rise, Size Does Matter

Nov. 13, 2013
I live at the beach in South Florida, an area considered by many to be at the greatest economic risk from sea-level rise in the world.

I live at the beach in South Florida, an area considered by many to be at the greatest economic risk from sea-level rise in the world. According to a 2009 Antarctic Science article, the melting of all of the world’s ice sheets and glaciers would cause sea level to rise approximately 212 ft above its current level. The average elevation in Broward County is 6 ft above sea level—less at the beach—and we have a large number of single-family homes and low- and mid-rise condos, mine included, all of which would become artificial reefs in that scenario. Fortunately, that’s not the immediate threat. The imminent danger is the steady rise in sea level. And it doesn’t just affect those living in coastal areas. Because it causes saltwater to infiltrate aquifers, it impacts those living inland as well.

Is there a link between climate change and sea-level rise? I believe there is. Physics tells us if the energy put into the Earth’s climate system exceeds the output, the energy balance will change, and the climate will be driven to a warmer state. How do warmer global temperatures affect sea level? We only have to rely on some pretty fundamental physics: When ice sheets and glaciers are heated above their melting point, they do just that—they melt. The ice, which was a white solid (high albedo), becomes in deep water a dark liquid, absorbing heat and melting further. The resulting increase in water temperature melts even more ice. You get the picture. What caused the initial warming—nature or man—doesn’t really matter.

Although I live, work, and play in South Florida, I didn’t fully appreciate the seriousness and significance of sea-level rise until I heard oceanographer and global ocean explorer John Englander lead a panel discussion as part of a local U.S. Green Building Council program. If you haven’t read John’s book, “High Tide on Main Street,” I suggest you do, particularly if you live in a coastal area. To me, the most striking point John made was that, even if we stop emitting greenhouse gases today, the sea level will continue to rise for a very long time. It’s a process not easily or quickly reversed, although that is not to say we shouldn’t continue to do what we can.

Don’t dismiss this as another of those problems we can leave to our children to solve. Shortly after moving to South Florida, I saw the effects of a spring tide and an offshore storm occurring simultaneously: a super high tide that lifted our boat to the top and almost over the seawall of our slip. A gentle tug on the bow line would have pulled it into the yard! The concurrence of rising sea level, normal tidal changes (caused by the alignment of the sun, the moon, and Earth), and a storm surge can be catastrophic. Remember Hurricane Sandy last year?

About the Author

Larry Clark

A member of HPAC Engineering’s Editorial Advisory Board, Lawrence (Larry) Clark, QCxP, GGP, LEED AP+, is principal of Sustainable Performance Solutions LLC, a South Florida-based engineering firm focused on energy and sustainability consulting. He has more than two dozen published articles on HVAC- and energy-related topics to his credit and frequently lectures on green-building best practices, central-energy-plant optimization, and demand-controlled ventilation.