News•January 9, 2014
The Front Lines of Climate Change: Charleston's Struggle
By Bobby Magill
The Front Lines of Climate Change:Global warming is, by definition, global, but the impacts of climate change will touch everyone on a local level. How each community responds will depend on its unique mix of people and geography. This story is part of a Climate Central series that looks at how communities are facing the challenges ahead.
CHARLESTON, S.C. — Local legend has it that the Atlantic Ocean begins here, where the Ashley and Cooper rivers come together to form Charleston harbor, overlooked by a city skyline dotted with church steeples and stately old homes.
Geographically, Charleston is the capital of the South Carolina Lowcountry, a city weaved from marshy islands and peninsulas. The Atlantic has long sent floodwaters into streets at high tide, particularly where wetlands and creeks were filled centuries ago to make room for development. The city is notorious for flooding during storms that drop more than an inch of rain, flooding made worse by the tides and rising water tables and sea levels.
A “groin,” a structure containing sand and helping to prevent it from washing away, deteriorates at Folly Beach, S.C.
Credit: Bobby Magill
Situated in the middle of the South Carolina coast and steeped in history, the city played a major role in the American Revolution and was the site of the first battle of the Civil War in 1861. Today, the Charleston area is home to nearly 700,000 people, a busy seaport ranked eighth in the nation for value of cargo handled and a popular tourist destination for its prominent place in American history, its charm and its beautiful beaches.
Charleston is also among the East Coast’s most vulnerable metropolitan areas to rising seas and a changing climate, which may threaten nearly $150 billion of infrastructure along the South Carolina coast. In the past century, the Atlantic has risen more than a foot along the coast near here and could rise an additional 5 feet by 2100, according to research on climate change’s impact on the Southeast released in November and used as part of the Third National Climate Assessment.
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Climate change will touch every American community in some way. Water may become more and more scarce for Los Angeles, Las Vegas and Phoenix and snow may decrease in the Sierra Nevada and the mountains of the Southwest. Sea level rise threatens to inundate low-lying Miami and other coastal cities. Snowpack in the Colorado mountains could melt earlier and faster, making water more difficult to capture for both drinking and agriculture. New York may be more vulnerable to hurricanes and other extreme weather.
These are the places that dominate the news. But while New York City and South Florida are developing plans to withstand and adapt to a warming world, most Americans do not live in the biggest metro areas. How those many disparate communities across the country plan or fail to plan for what's ahead will determine how well they weather climate change.
Charleston, a vulnerable city in a region highly skeptical of climate change, symbolizes the challenges many smaller cities face. Here, the difficulty in acknowledging the reality and science behind climate change itself complicates planning for the risks it poses.
A City At Risk
Climate change is a significant threat to the Lowcountry. Today, high tides flood the edges of the city — tidal flooding that has destroyed homes on barrier islands south of the city. Scientists are unsure if the Lowcountry will become wetter or drier because of climate change, but the future is likely to be much warmer in the Charleston area, which could see an additional 30 days of temperatures higher than 95°F by 2070.
Up to 5 feet of sea level rise will threaten the richness of the Lowcountry’s estuarine ecosystems, with marshlands stressed by seawater inundation. Beach erosion will need more remediation, and there will be tax implications for landowners who lose property to rising seas. All development along the coast will become endangered by hurricane storm surges made more severe by higher sea levels. Costs to modify roadways to withstand sea level rise could mount up to $3 million per lane mile.
That is what scientists believe is in store for the Lowcountry in the coming decades, said Kirstin Dow, a climate hazards and vulnerability specialist and associate professor of geography at the University of South Carolina, and co-editor of the 2013 “Climate of the Southeast United States” technical report submitted for the Third National Climate Assessment.
“It’s important if you’re living on the coast or near the coast or interested in the economic well-being of South Carolina to pay attention to what’s happening here,” she said. “The threats are real. We’re going to see it in the cost of maintaining structures on the coasts. It’s not something we’re going to be able to escape.”
Homes built up to the high tide mark at Folly Beach, S.C., have to shore up their foundations to keep them from eroding away.
Credit: Bobby Magill
The way rain falls in the area is also changing, and the city’s drainage system is struggling to keep up, said College of Charleston biologist Phil Dustan, who studies the ecological effects of sea level rise in the region.
“Every time it rains, it floods,” he said, adding that the region gets the same amount of rain annually, but it falls in fewer but more intense rain storms. That is consistent with climate change-related trends across the U.S. and much of the Northern Hemisphere. “Rain bombs,” he said, overwhelm the city’s low-lying areas and the city’s drainage system.
Charleston has several floodwater pump stations that slowly drain the flooded streets, pumping the water into tunnels 140 feet below ground, sending the water beneath the Charleston Harbor.
But that system can only do so much, and even though it can handle a lot of water, it takes time to drain all the streets.
“It’ll handle a 10-year storm event — 6.8 inches of rain in a 24-hour period,” Charleston Public Service Director Laura Cabiness said. “Really, if you think about what happens in Charleston, these nuisance floodings happen several times a year.”
As the climate changes, the Lowcountry can expect to see rain fall more intensely in short periods of time, something rainfall data is already beginning to show as “rain bombs” become more frequent, Dustan said.
The past two decades have seen increases in extreme precipitation events across the entire region, and urban areas are particularly at risk of flooding because there are many impervious surfaces, forcing water to run off pavement, according to the “Climate of the Southeast United States” technical report.
In Charleston, marshy areas that were filled for new development see the most flooding and get the brunt of the effects of a rising sea. In some areas, the land is actually sinking naturally as sediments — either soil deposited naturally or by humans to create more land to build on — compact over time. When land sinks, it increases the average level of the sea relative to the surface of the land in a specific area.
“All these fill areas are subject to subsidence, so not only are you getting increased tidal elevations, you’re getting subsidence of the land,” Cabiness said, adding that when streets in those areas are rebuilt, they’re often built higher than they were before, sometimes by a foot or more to account for future sinking.
Beachfront and marsh erosion has long been a problem near Charleston, and despite efforts to renourish beaches and stabilize beachfront homes, it is a losing battle with nature and a rising Atlantic, though that is occurring in some areas more than others, Dustan said.
“The long-term impacts from loss of land are a huge risk, especially as marshfront property owners inevitably harden shorelines to protect what they have and marshes lose the ability to migrate inland,” said Jessica Whitehead, coastal communities hazards adaptation specialist at the North Carolina Sea Grant at North Carolina State University and former coastal climate extension specialist for the South Carolina Sea Grant.
Action and Inaction
Sea level rise is also a serious concern for the Charleston area’s coastal wetland ecosystems, which are likely to see habitat loss, seawater encroachment, flooding and harm to water quality, according to a report the South Carolina Department of Natural Resources published in 2013, outlining the ecological challenges the state faces in a changing climate.
The report — released amid political turmoil within the agency partly because of its explicit admission that climate change is both real and manmade — makes clear that climate change’s impact on South Carolina will be dramatic and dangerous.
Among its findings: Some aquatic species could disappear from the state entirely. Algae blooms could destroy marsh grass along the coasts, poison shellfish and “bioaccumulate” toxins in the food chain, potentially killing both wildlife and humans. Biological “dead zones” could appear in coastal waters. Coral reefs could be harmed. Coastlines will continue to erode. And so on.
About halfway through the 101-page report, on page 56, the Department of Natural Resources declared this:
“Interest in the effects of climate change in the Southeast is increasing, but there are any number of impediments to understanding and predicting climate change, including public apathy and a lack of awareness, lack of outreach on adaptation options, lack of uniform access to information on current climate change risks and a lack of guidance on what information and tools are available.
“Climate change documentation and development of adaptation strategies also are limited primarily by a lack of funding, a lack of political will and a lack of government leadership. Leadership issues may be a result of division of authority across topics as well as geographic and political boundaries across federal, state and municipal governments. All of these factors impede development of effective climate change adaptation policies across the Southeast.”
After sending the report to Climate Central, South Carolina Department of Natural Resources officials did not respond to requests for comment about it.
“When the DNR comes out and says something like that, it’s huge,” Dustan said. “It’s bigger than you can ever imagine.”
Dustan said the report's direct acknowledgement of climate change and its possible effects was welcome change in a state government long resistant to drawing connections between human activity and climate.
Some streets in Charleston, S.C., see minor flooding at high tide.
Credit: Bobby Magill
Addressing climate change and its consequences in South Carolina has been wracked with controversy in recent years, as little action has been taken following the release of reports detailing the risks the state faces.
The state environment department’s Shoreline Change Advisory Committee issued a report in early 2010 acknowledging the role that climate change plays in altering the state’s coastline and made a series of recommendations for how coastal communities can adapt to sea level rise and a changing coastline.
The report recommended that as local cities and towns update their hazard mitigation plans, they include the risks posed by climate change, something that has never been required.
The 2010 report, which references sea level rise 43 times, was used as the basis for a state-appointed “blue ribbon” committee to recommend ways the state can revise its laws and regulations governing beachfront management. The state environment department created the committee to address a “crisis” on the state’s beaches, where little direction existed to deal with chronic erosion, gradual sea level rise, increased shoreline development, population growth and a lack of comprehensive beachfront planning.
The blue ribbon committee’s final report was released in early 2013 — without a single mention of climate change and only one reference to sea level rise. Beach renourishment projects and other efforts to stop erosion are major topics in that report, but its only reference to sea level rise is citing it as a reason the South Carolina Legislature passed a 1988 state law that regulated the management of the state’s beachfronts.
It’s a similar picture at the local level.
The Charleston City Council created a “green committee” in 2007 to develop a city sustainability and climate change action plan.
The committee’s “Green Plan” was released in 2010 and set specific goals to temper the city’s climate impact: Reduce greenhouse gas emissions 30 percent by 2030. Make the city’s buildings more energy efficient. Establish a renewable energy goal of 15 percent by 2020. Create a sea level rise adaptation plan. And so on.
“The Green Plan was received by City Council, but was not adopted,” city of Charleston spokeswoman Barbara Vaughn said. “The City of Charleston’s comprehensive plan update, (the) Century V Plan, was adopted following the Green Plan’s creation and weaves within it many sustainability principles, many of which the city of Charleston has embraced for decades.”
The Century V Plan envisions the city adapting its land uses to hazards posed by non-specific kinds of coastal flooding and hurricanes, but it mentions nothing of climate change, sea level rise or how the city and its land-use goals could be affected by either.
“It has been quiet in terms of talking about climate change explicitly and thinking about what the state needs to do to prepare for it,” said Hamilton Davis, energy and climate director for the South Carolina Coastal Conservation League, a Charleston-based environmental group that was vocal in the city’s development of the Green Plan.
The city and the surrounding communities are primarily dealing with the beachfront and coastal erosion issues that they’ve been facing for decades without projecting into the future to consider what might happen to barrier islands, beachfront properties and coastal ecosystems as the sea levels continue to rise, he said.
“Developing and implementing policies related to sea level rise is challenging given the costs, community perceptions and the lack of global, national and state direction,” Vaughn said.
The city did not respond to requests for more details about those challenges and how it might overcome them.
Acting and Connecting the Dots
Finding solutions to climate change will involve convincing people there’s a problem to be solved in the first place. That’s one of the biggest challenges any city faces in figuring out how to prepare for climate change and how to find the money for what may be monumental projects to protect homes and businesses from drought, rising seas and other ravages of global warming.
Homes line the beach at Folly Beach, S.C.
Credit: Bobby Magill
Dustan said he sees Charleston’s flooding problems as evidence the city isn’t thinking far enough ahead to deal with climate change while residents in the area don’t even acknowledge the existence of it.
“What they’re trying to do is just get the water off the land as fast as possible,” Dustan said, referring to the city's floodwater drainage system. “I don’t think they’ve connected global warming and rain flooding events quite yet. They haven’t connected the urban heat island effect. They haven’t really connected those dots.”
One of the roots of the problem of getting communities in South Carolina to find solutions to these problems lies in the time scale in which the ravages of climate change are expected to take hold, Whitehead said.
Sea level rise is expected to accelerate over a period of decades.
“So, to ask other (city planning) staff and elected officials to look beyond their usual planning horizons to the time when we see the really big projected climate and sea level changes for the South Carolina coast represents a large shift from the way municipalities have planned in the past,” Whitehead said.
Progress to plan for the impacts of climate change in South Carolina can be done, but adaptation will prove tricky, she said.
“For example, wastewater operators have told us higher water tables and more frequent flooding events could lead to more pressure on pipes,” Whitehead said. “Older pipes may crack and even lead to inflow into wastewater systems, raising treatment costs. I’ve also heard municipal staff worry about the roads issue. More frequent flooding cuts off public access more frequently, and ultimately damages the roads. However, if you raise the road elevations, you risk flooding lower properties nearby, so there’s no easy adaptation solution.”
Charleston, Cabiness said, is doing a lot to address adaptation to a changing climate, “but nobody has combined it into a document that says, this is all the things we’re doing making us more resilient.”
She said Charleston is making smart choices, and that officials are thinking about how the climate will affect the city 50 years from now and what's reasonable to act on now.
“The challenges are trying to convince somebody it might be good to build a foot or two higher than ordinances and building codes require,” she said. “You’re asking people to spend more money on speculating on what’s going to happen in the future.”
People will be motivated to act when they have more information about how much it’s going to cost to adapt to the changes that are coming, Whitehead said.
“One thing I’ve learned in five years of extension work with coastal communities, it’s that if you want people to change behavior, you have to successfully make the case that the behavior change is both necessary and feasible,” she said.
The need for action is urgent because so much of the Lowcountry is at stake, Davis said.
“We've lost 1,200 acres of the barrier islands in the last decade,” he said. “Those are massive impacts. And then, of course, driving on places like the Charleston Peninsula during those heavy rain events, during the high tides, you get the sense that our infrastructure isn't capable of dealing with where we are today.”
Several years ago, Davis said, the north end of the Isle of Palms just up the coast from downtown Charleston saw beach erosion that was threatening million dollar homes and a golf course and, “that experience is going to be typical of what we'll see more and more of.”
Still, in a city of stately homes so close to a rising sea, that point has not yet been driven home to everyone.
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