What better place to talk about the impacts of sea level rise than a coastal city on a barrier island on the Gulf Coast? That’s where I was two weeks ago – in Galveston, Texas, with 80 other Earth scientists at a conference sponsored by the Geological Society of America and the American Geophysical Union. Galveston was the site of the worst natural disaster in U.S. history, more than a century ago.
The Galveston seawall
You may have heard about the devastating hurricane that hit the island on September 8, 1900, destroying the city and killing thousands of people. As a result, the residents built a seawall that now extends for over 10 miles along the seaward shore. Halfway through the week-long conference we took a tour along that very seawall. It’s an amazing piece of engineering – 16 feet deep and 17 feet high – much more imposing than I expected. As I stood looking down the gentle curved concrete, I wondered how long this wall could hold back the ocean.
A 10-mile long seawall, begun in the early 1900s after the worst natural disaster in U.S. history, extends along the coast of Galveston Island. Photo: M. Fitzpatrick
Hurricane Ike: over a hundred years later and with sea level almost three feet higher
Walking the streets of Galveston, climate impacts became more real for me. Every second person I met had a story to tell about where they were and what they were doing when Hurricane Ike hit in the middle of the night on September 13, 2008. The damage was not nearly as serious as it was a hundred years earlier. But as I imagined folks in their pajamas, grabbing children and pets and seeking higher ground, I thought Ike would have been just as terrifying.
Ike was only a Category 2 storm when it made landfall (on a scale that goes to 5, that’s like being in the featherweight division), but the water still topped the Galveston seawall and resulted in massive flooding. Buildings throughout the city are still unoccupied. High water marks from Ike are sign-posted at several restaurants, near a street lamp and on a wall. These insignias were almost a foot above my head – and I’m not terribly short! If this was the resultant flooding at current sea levels what will it be like when the sea is even higher?
Coastal development along the shoreline of Galveston Island is already at risk from inundation during storm events. Photo: M. Fitzpatrick
Healthy natural buffers protect coastlines
The sea along the Gulf Coast is rising faster than anywhere else in the United States. Galveston has seen a 3-foot rise in local sea level since the late 1880s, due to a combination of impacts from global warming and from subsidence of the land surface. Higher seas mean higher storm surges and potentially more damage from flooding as explained in a new UCS infographic.
During the week at the conference, we heard experts from around the world explain that traditional defensive approaches – like building seawalls and levies – may no longer be adequate. We also need healthy natural buffers – such as barrier islands, tidal wetlands, and mangroves – that contribute to stabilizing and protecting coastlines.
Communicating coastal impacts to policymakers and the public
One of the outcomes of this important conference was a recognition that scientists need to be more closely involved with policy makers. The group of 80 scientists drafted a set of key statements, with these top line messages (watch for a link to the final statement in the near future):
- Global sea level is rising at an accelerated rate overall in response to climate change.
- Current rates of sea level rise in many regions are unprecedented in the last several thousand years.
- Sea level rise will exacerbate the impacts of extreme events, such as hurricanes and storms.
- Society must learn to anticipate, live with, and adapt to the dynamics of a rapidly evolving coastal system.
To find out how sea level rise affects our coasts, here is a brief overview developed by UCS. In a blog from last week, my colleague, Rachel Cleetus, describes what steps experts from five different coastal states are already taking to address the challenges posed by rising seas and how they are increasing local preparedness.