Many coastal communities in the U.S. are grappling with how best to protect low-lying areas from flooding as sea levels rise, but some of those efforts are generating disputes over costs, government regulations and the validity of climate-change studies.
Over the past century, the global sea level has risen about 8 inches, according to a draft climate report released earlier this year by a National Oceanic and Atmospheric Administration advisory committee. Many scientists say the rate of rise is accelerating as sea temperatures warm and ice caps melt. But some argue the rate has remained constant or is even decelerating. The climate report projects that sea levels will climb an additional 1 to 4 feet, and possibly higher, this century. If that happens, it could have deep implications for the 5 million U.S. residents who live in areas less than four feet above high tide, half of whom are in Florida, according to a 2012 report by Climate Central, a research organization that aims to measure the local impact of climate change.
The issue has gained urgency in the wake of last year's superstorm Sandy, which unleashed a destructive storm surge along the Eastern seaboard that many scientists said was exacerbated by rising sea levels. The debates in coastal communities revolve around how best to prepare for potentially devastating future storms while not overburdening tight budgets.
In the aftermath of Sandy, New York Mayor Michael Bloomberg set out to determine how the city could fortify itself. This past week, he unveiled a $20 billion plan to build a network of floodwaters and levees, among other things. While many politicians and residents lauded the proposal, some fiscal conservatives raised concerns about the price tag.
Similar exercises in other parts of the country have proved controversial. In North Carolina, the Coastal Resources Commission, a state agency that establishes policies on coastal development, issued a report in 2010 that predicted a sea-level rise of as much as 39 inches by 2100. That inflamed some coastal residents and business leaders who feared the projection would lead to higher insurance rates.
A nonprofit group in the state called NC-20, which focuses on coastal development from an economic perspective, challenged the commission's findings, citing researchers who contest that sea-level rise is accelerating. After intense lobbying by the organization, the state enacted a law last year that effectively barred use of the 39-inch prediction for regulatory purposes.
"It's about preventing damage to the economy from excess, egregious regulation," said Tom Thompson, NC-20's chairman. Environmental groups countered that it was an attempt to legislate away reality.
In South Florida, more-frequent flooding during high tide in some areas and other effects of rising sea levels have stoked a public debate. Four counties-Miami-Dade, Broward, Palm Beach and Monroe-formed the Southeast Florida Regional Climate Change Compact in 2010 to coordinate research on weather change and develop responses to it at a government level. Last year, the group released an action plan with 110 policy recommendations, including determining which utilities may need to be reinforced or relocated as a result of increased flooding threats.
The problem is that estimates of sea-level rise span a wide margin, said Nichole Hefty, chief of Miami-Dade's office of sustainability. "If we knew for certain it was going to rise a foot in the next 30 years, we could say, 'OK, let's look at a capital improvement plan,' " she said. Instead, officials are left with a tough choice: How much should they invest now to defend against a still-imprecise threat?
That question is at the heart of a dispute over a $1.6 billion upgrade of the Miami-Dade sewer system, which is old and prone to spills. The project is part of a consent decree announced this past week that settled an Environmental Protection Agency lawsuit over sewage overflows.
Biscayne Bay Waterkeeper, an environmental advocacy group, challenged the proposed agreement in federal court earlier this year, arguing that it failed to account for rising sea levels, leaving some coastal treatment plants prone to disaster in a storm. "To rebuild these systems at current elevation, with no hardening, no sea walls...is the height of irresponsibility," said Albert Slap, an attorney for the group.
Doug Yoder, deputy director of the Miami-Dade water and sewer department, responded that the county is indeed studying ways to protect plants against rising sea levels-such as elevating electrical systems-just not as part of the consent decree.
Up the Florida coast, another conflict flared recently over a regional planning group called Seven50 that includes seven southern counties, from Monroe to Indian River. The group, which includes public and private entities, aims to boost the area's economic competitiveness and in part is addressing the effects of climate change.
A number of Indian River residents decried the organization's work as an attempt to quash private-property rights by imposing sustainable-development initiatives on municipalities. Seven50's blueprint for economic prosperity is "a socialist document," said county commissioner Bob Solari.
He and fellow commissioners voted to withdraw from the group last December, after nearly 200 opponents of the effort packed a commission meeting to express concerns. The next month, the city council in Vero Beach, part of Indian River, did the same.
That sort of resistance imperils efforts to prepare for future Sandys, said Harold Wanless, a geologist at the University of Miami. Too often, he said, "people aren't willing to think through the reality of what's coming up."