Rising tides
On the way back to the hotel, we had an interesting discussion about the accelerating rate of sea level rise and coastal residents. It would have been interesting to knock on doors and ask people what they know about sea level rise and human contributions to it. The response would probably have been something to the effect of, “Why should I be worried about sea levels in 50 years when I’m worried about high tide right now?” To which my honest response would have to have been: good point. But it got me thinking… what’s the appropriate outreach strategy for issues of climate change and sea level rise?
Sea level rise is a tricky problem in climate change research. It’s not that the sea level is rising – that’s been happening since the end of the last ice age. The problem is that the rate at which the sea level rises is accelerating. In 2007, the Intergovernmental Panel on Climate Change (IPCC) published an estimated total global rise in sea level of about 7-23 inches (18-59 centimeters) by 2090-2099. It’s a wide range, but the difference comes from various scenarios of how fast we’re emitting the harmful greenhouse gases that contribute to climate change. However, the IPCC didn’t factor in issues with melting ice sheets. Pfeffer, Harper, and O’Neel published a study in 2008 that suggests including the ice flow dynamics raises our most plausible estimate of global sea level rise by 2100 as about 31 in (80 cm). Unfortunately, they also state that they can’t rule out a potential sea level rise of about six and a half feet (2 meters) by then. Of course, it’s a matter of someone conducting further research that supports or refutes the Pfeffer et al. estimates, but it’s still a scary thought.
As if this doesn’t sound complicated enough, remember that we’re talking about global sea level rise here. When we’re thinking of the impacts sea level rise has in the Carolinas, we’re really concerned about regional sea level rise. Local factors, like the local elevation, whether the land is rising or sinking, and human modifications (among other things), are what determine the change in sea level you may see along Folly Beach or in the marshes of the Albemarle Sound. And we don’t know much yet about how changes in sea level rise (even small ones) affect erosion rates or patterns, meaning that we don’t really know how erosion from coastal storms will change the shoreline, either. As a result, the maps of sea level rise that decision-makers have to work with, which superimpose sea level rise models on today’s topographical maps (like the ones you currently see online), may not reflect what would really be inundated.
So from an outreach standpoint, what do we do? Planning for sea level rise is easier now – even if a region works on a 20 year plan for growth, the growth that occurs between now and 2030 affects growth from 2030 to 2050, and so on until that foot or two of sea level rise catches up to you. But the information we have to give people is OK at best from a scientific standpoint (and less than OK in areas of the Carolina coastlines where we don’t have the most up to date data on elevations). Regardless, we at Sea Grant are hearing growing buzz from planners and officials along both the North and South Carolina coasts who are thinking about sea level rise. This puts us yet again in the position where we have to move forward with planning even though we have imperfect information – i.e., we have to make do with what we have so far. Nate Kettle, a CISA grad student at the University of South Carolina, and I are putting together the second in a series of “Frequently Asked Questions about Climate Change” that focuses on answering questions residents in the Carolinas may have about sea level rise. After that, we’ll see what our Sea Grant stakeholders ask for during the needs assessment I’m about to conduct (more on that later).
And as for pictures like the ones I took at Nags Head? The owners of those homes might not care – but by presenting these pictures along with a little education on sea level rise, perhaps it’ll give some of the property owners a few houses inland something to think about.
