Last month, a group gathered in a conference room beneath the Marriott Marquis hotel in Washington D.C. They were there to discuss a question that’s relevant to all coastal residents: We know climate change is causing sea level to rise, but just how much will the water go up?
The discussion was one small part of a massive Earth sciences conference organized by the American Geophysical Union. For five days, roughly 25,000 scientists descended on Washington, many of them to discuss why and how the climate is changing.
But the group gathered beneath the Marriott was different. They were among the few attendees whose job was not to study climate change, but to figure out what to do about it. This was a session for practitioners—city planners and engineers, for instance—and the scientists they work with. In other words, the people tasked with making sure cities remain intact as the world changes around them.
At Rockaway Beach in Queens, New York, for instance, they’re building a seawall buried inside a sand dune…
Sea level rise is one of the issues that keeps these folks awake at night. In recent years, estimates of the worst-case scenario have varied wildly—from under one meter to over three meters of sea level rise by 2100—and changed frequently.
“And this is really challenging,” said Philadelphia Chief Resilience Officer Abby Sullivan. How’s a practitioner to know how much water will come knocking at the door when scientists change their minds every few years?
Take the Army Corps of Engineers’ plan to protect the New York/New Jersey area from another Superstorm Sandy-like event, for example. The Corps is tentatively planning to spend $52 billion on seawalls, levees, breakwaters, and the like to protect New York City and surrounding areas from another event like the 2012 storm, which caused widespread flooding and $19 billion in damages.
“People are spending just scads of money based on this problem,” said climate scientist Timothy Bartholomaus from the University of Idaho. If working with a more accurate prediction of sea level rise can save even a fraction of a percentage of the cost, “I think that sounds like a really worthwhile investment,” he added.
At the same time, revamping design plans every time climate scientists come up with a new estimate of sea level rise would be an overreaction, some participants said. At some point, practitioners have to stop planning and actually do something.
To strike a balance between caution and pragmatism, one has to be willing to bend a bit and consider risk tolerance on a project-by-project basis, said William Veatch from the U.S. Army Corps of Engineers.
At the same time, “We are in the army, so of course we have regulations,” Veatch said. He proceeded to describe the regulations the Corps uses to incorporate flexibility into regulations, but things got far too convoluted for this reporter to follow.
His examples were more straightforward. At Rockaway Beach, in Queens, New York, for instance, they’re building a seawall buried inside a sand dune to protect against storm surges. It’s easy to add height to the wall and the dune later if need be, so they’re planning for relatively minor sea level rise to keep the cost low.
An elevated roadway, on the other hand, is hugely difficult to raise once it’s been built, so here they’d plan for the worst-case scenario.
Figuring out how to turn scientific publications into this type of risk-benefit analysis is a lot of work for overburdened practitioners. Sullivan said she sometimes does this work “at 11pm, you know?”
She asked the group whether there should be a central U.S. government agency that reviews new scientific evidence on sea level rise, decides whether it’s mature enough to warrant consideration, and issues advice to practitioners. In the United Kingdom, the country’s national meteorological service plays this role.
The response was mixed, with some session participants thinking such a thing is sorely needed and others fearing that a central authority might try to impose a one-size-fits-all solution on a country that values individualism in all aspects of life.
As the session wound down, the tone was a funny contrast to the climate scientist’s habitual refrain of “When will people take us seriously?” Here, the message seemed to be, “How can we take this just seriously enough?”
