By Ludwig, Fred
We all take some things for granted: The shoreline will stay about where it is now. The weather will follow the rhythms of the seasons, delivering disasters every now and then, but in predictable ways.
Such assumptions often form the foundation of community design. But like supporting structures of concrete or masonry, expectations can also crumble under too much pressure. If climate change ushers in very different conditions, communities someday may face a range of problems from coastal inundation to drought to flash floods.
Whether they're on the coasts or well inland, officials are starting to wonder how to cope if a new climate brings severe changes. "A lot of states are just trying to get their heads wrapped around this right now," says Kacky Andrews, executive director of the Coastal States Organization, based in Washington, D.C.
Discussions about how to adapt are being fueled by a changing political climate and a convergence of immediate problems. Estimated sea levels rose more than half a foot in the 20th century. Coastal planners and property owners face erosion damage. A spate of fierce hurricanes has reminded U.S. coastal communities--and insurers--of their vulnerability.
Some effects may be unavoidable. According to the Intergovernmental Panel on Climate Change, sea levels could continue to rise for centuries even if greenhouse gas levels stabilized. IPCC scientists concluded this year the planet is likely to see more heat waves, hurricane intensity, and forest fires. Higher temperatures may increase disease transmission and strain electricity supplies. The panel predicted additional sea-level rise of seven to 23 inches in the 21st century.
Coastal communities may face a fundamental choice: Do they try to fortify their shores to keep waters at bay, or sound the retreat and just let the sea advance? In general, communities are likely to mount a defense of heavily developed areas, notes James Titus, the U.S. Environmental Protection Agency project manager for rising sea level. He says officials are likely to choose retreat as an option for undeveloped lands.
In partly developed areas where future uses are uncertain, the choice is harder to predict. But those areas are where planning can make the greatest difference--especially ahead of development.
"You can make the decision, rather than letting the decision just sort of evolve out of unintended consequences," Titus says. He has been preparing maps that will show lands likely to be protected from rising seas.
Some important actions can wait. Sea walls may not have to go up until they're needed. But communities that decide on retreat may want to set rules well ahead of time to try to keep development and infrastructure inland.
Love it or leave it?
People have always been drawn to the water, building the foundations of civilization along the Euphrates, the Tiber, and the Aegean. But the dangers of the sea have also long had a place in human consciousness, whether in the form of mythical monsters of the deep or real storms and floods.
In the U.S., about 5,000 square miles of dry land lies within two feet of high tide, according to the EPA. That includes costly development and critical infrastructure. Rapid sea-level rise could swallow some awfully expensive real estate.
New maps compiled by the San Francisco Bay Conservation and Development Commission showed a roughly three-foot sea rise would deluge two airports and parts of downtown. A study by the Pacific Institute in Oakland concluded in 1990 that options for protecting the city from the extensive damage of such inundation would include elevating buildings and freeways, erecting levees, and replenishing beaches.
With some $2 trillion in insured exposure on its heavily populated coasts, Florida is the state most vulnerable to natural disasters, according to the New York-based Insurance Information Institute. The state's economy and sun-soaked lifestyle would suffer under a severe sea-level rise that would inundate large areas. Despite the state's rigorous hurricane-resistant building codes, hurricanes in 2004 and 2005 led to soaring home owner insurance rates. Florida lawmakers this year allowed the state insurer to write more policies in response.
Other Gulf Coast states have faced similar problems--and those problems could worsen if climate change brings even worse hurricane damage. "I think what we'll see is a slow trend in building decisions and buying decisions, wherein the costs of risk associated with living in certain areas will impact those decisions," says Nebraska Department of Insurance Director Tim Wagner, who testified at an April workshop for the Florida cabinet (the governor and three other top officials).
At the southern end of the state, Miami-Dade County is pondering its choices. "As a low-lying coastal community, however much time there is (to adapt), we probably have less of it than people living in a lot of other parts of the country do," says Doug Yoder, deputy director of the Miami-Dade Water and Sewer Department.
The county's new Climate Change Advisory Task Force is addressing a range of issues, such as fears about the water supply. South Florida gets most of its water from the giant limestone sponge beneath it--the highly porous, highly productive Biscayne Aquifer.
Use of the aquifer is now being curtailed to protect the Everglades, so managers have been looking elsewhere to meet the needs of rapid growth. But the aquifer, just a few feet down in places, is especially vulnerable to contamination. With rising seas, it may also be vulnerable to saltwater intrusion. Miami-Dade County expects to create alternative systems for about one-quarter of its water supply within 20 years, including a desalinization process in production by 2012, Yoder says.
If a hurricane as powerful as Hurricane Katrina were to sweep New Orleans decades from now, would it defeat the flood protection system in effect then? Design flaws that undermined flood walls in 2005 presumably would be fixed. But future sea levels might be much higher, especially given the city's heavy land subsidence, and rising waters may swallow even more wetlands in the years to come. Those wetlands are a first line of defense against a hurricane.
It is difficult to say how much capacity a hurricane protection system needs in order to account for the dynamic interactions of the Louisiana coast under a changing climate, says Richard Luettich Jr., director of the Institute of Marine Sciences at the University of North Carolina, Chapel Hill.
U.S. Army Corps of Engineers reconstruction engineers are still considering climate change, says Al Naomi, a Corps branch chief in New Orleans. Officials are building in extra capacity in some cases, under the assumption that the walls will still function 50 years from now, he says. State and local officials are emphasizing the importance of considering sea-level rise in the project.
The Coastal Protection and Restoration Authority, the agency chartered by the legislature to coordinate coastal restoration, is calling for wetlands restoration. More than 1.2 million acres of coastal Louisiana have gradually disappeared since the 1930s, the agency reports. Katrina and Rita alone removed 200 square miles of marsh.
River dams can choke off wetlands by halting the delivery of sediments and nutrients. In Louisiana, a study group formed by the Army Corps also blames canal dredging, oil development, erosion, rising seas, and geologic forces.
In addition to absorbing the force of storms, wetlands are vital parts of the waters along them, providing habitat, slowing erosion, and filtering pollution. Wetlands have shown a natural resiliency amid sea-level rise, often migrating inland--when the change is gradual. But if development blocks their path, wetlands may have no room to move.
Structures such as sea walls keep waters at bay but can cause the adjacent beaches to erode entirely. Other defenses such as bulkheads and revetments help protect private property against erosion but can upset the coast's natural balance.
On the Chesapeake
On the Chesapeake Bay and its tributaries, the thousands of miles of shoreline include a mix of swamps, marshes, and other wetlands with different levels of salinity. The sprawling, shallow bay is fed by fresh water pouring in from rivers such as the Susquehanna River in the north. Farther south, closer to the Atlantic, the water turns brackish. The changing waters provide distinct habitats that support at least 2,700 plant and animal species.
The Chesapeake has been part of the areas history even before it was mapped by Captain John Smith (of Jamestown fame) in 1608. Today, the bay still supports the economy of nearby communities, where the services range from kayak rentals to dockside restaurants offering all-you-can-eat blue crabs. The watermen of the Chesapeake speak their own dialects--speech preserved by their connection to the isolated bay islands well off the mainland, says Josh Voelker, of the Chesapeake Bay Program, a federal-state restoration partnership based in Annapolis, Maryland.
But the islands are eroding. Subsidence has combined with rising waters to drive the Chesapeake's level up about one foot over the last century, nearly twice the global average. Residents abandoned a number of shrinking islands throughout the 20th century.
"Sea-level rise is really threatening, and has already threatened, a lot of the way of life of the people in Maryland," says Zoe Johnson, Maryland Coastal Program natural resource planner. Also at risk are the tidal wetlands of the Eastern Shore, one of the Mid-Atlantic's largest expanses of coastal wetlands. The low-lying, almost-flat area rises only gradually away from the bay, exposing large areas to inundation.
Maryland has been doing extensive mapping--and calculating erosion rates--to aid shore management. It also promotes the use of "living shorelines" that combat erosion by restoring marshes, an environmentally friendly alternative to structures such as bulkheads.
The approach varies with the site but typically starts with clearing of debris, says Bhaskaran Subramanian, natural sciences manager at Maryland Eastern Shore RC&D Council, Inc., a group sponsored by soil conservation districts and nine county governments. The work can involve placing rocks out into the water, backfilling with sand, and planting marsh grasses, Subramanian says.
A required 100-foot buffer of natural vegetation allows no new development except access or water-related structures. The measure is part of Maryland shore restrictions enacted for the Chesapeake in 1984 and expanded to the state's Atlantic coastal bays in 2002.
On the Maine coast, state restrictions include a ban on seawalls and other shore armor for new development along the sand dune system. "The idea is to allow the system to function in a natural way," says Peter Slovinsky, a state coastal geologist. However, little of Maine's coast is beachfront. Looser restrictions apply on such areas as rocky bluffs.
The opposite problem
"Our water management systems are built assuming the climate of the last 100 years is going to happen in the next 100 years," notes Rosina Bierbanm, dean of the University of Michigan School of Natural Resources and Environment.
With climate change, that would be a bad assumption. Just as coasts may get too wet, some inland areas may get too dry. The Great Lakes, the world largest freshwater system, could see a drop in water levels due to evaporation.
Such a decline could affect global shipping and the communities on both sides of the U.S.-Canadian border. Even a small drop in overall water levels can force ships moving through the shallow channels to reduce their loads and make more trips, says Thomas Croley, National Oceanic and Atmospheric Administration research hydrologist. Lower levels could also force relocation of docks.
Evaporation and a drop in precipitation could strain water supplies, especially in the West. Water managers there already struggle with population growth and over-allocated water resources. They rely on the snowfall and snowmelt to replenish rivers through spring and into summer. But these days the water is melting earlier in the year, reducing flows during the hot months when communities need it most.
Some states are calling for more conservation. This year, a California senate bill that included two new reservoirs and $200 million for conservation programs was voted down in committee, but the administration vowed to bring the measure back. The 2005 version of the California Water Plan, issued every five years, included a broader-than-normal range of options, including desalinization and water banking.
Another problem: Water managers along some western rivers must also protect endangered fish habitat.
In Washington, the threatened Chinook salmon population has dwindled below 10 percent of its historic numbers in the Snohomish River basin. A 2005 salmon recovery plan outlines a 50-year restoration effort. But a NOAA study released this April noted that higher Snohomish River water temperatures and the altered flows caused by climate change will make recovery targets harder to reach. Researchers predicted declines in spawning populations of 20 to 40 percent compared to current conditions, although restoration efforts could offset some of the decline.
King County is helping to improve Snohomish habitat, and it is looking to stretch its water supplies. Plans call for the county's $1.7 billion Brightwater Treatment Plant, now under construction, to produce seven million gallons of reclaimed water a day by 2010. The project is part of the county's climate plan, issued in February.
More than 100 goals in the 178-page document include measures aimed at adapting to sea-level rise, flooding, and water supply strains. The plan calls for upgrades to the county's 500 levees and revetments and a countywide fee to fund flood control. Changed conditions will be worked into designs of roads, bridges, landscaping, and efforts to protect water quality in Puget Sound and its tributaries.
The county issued the report after hosting a climate change conference in 2005 and forming an interdisciplinary global warming action team last year. The conference led the county and the Climate Impacts Group at the University of Washington to create a guidebook on climate change for local and regional governments. Publication was pending by ICLEI--Local Governments for Sustainability. The group expects to have the book available on its website by late summer.
Overall, the Intergovernmental Panel on Climate Change predicted drought in the Southwest and heavier precipitation in the Northeast, but whatever ultimately happens, precipitation is expected to arrive in stronger storms.
Many older communities in the Great Lakes and Northeast use combined sewer systems that carry both wastewater and stormwater. When rain is heavy enough to overwhelm the systems, a toxic brew of untreated sewage and industrial wastewater can pour out into rivers and lakes.
Some of the systems are 100 years old, says Joel Scheraga, national program director for EPA's Global Change Research Program. If climate change brings stronger storms, that could undermine the effectiveness of systems designed for past conditions, a draft report from an EPA study reported last year.
"You don't want to make the investment (in a new system) with the belief that it will meet the EPA standards, and then discover 50 years from now after the climate has changed that the systems aren't performing as you anticipated," Scheraga says.
Conditions on the ground
When it comes to land use, the nation is likely to adapt to the global threat of climate change at the local level. That means the response could be a policy patchwork that varies not only from community to community, but perhaps even from one plot of ground to another, depending on specific environmental, political, and economic conditions.
Under the federal Coastal Zone Management Program, which is voluntary, the 34 states, territories, and commonwealths that participate get federal matching grants, but each devises its own approach to preservation and development. "States love the flexibility that provides," says Kacky Andrews of the Coastal States Organization.
The program awards about $66 million in annual grants for work along the oceans and Great Lakes, a figure that has been flat for several years. The coastal states group typically requests $90 million. Many coastal managers called for more funding last October and November, when NOAA sought input in a comprehensive program review ahead of planned congressional reauthorization of the Coastal Zone Management Act. Local officials cited climate change as a key emerging issue. NOAA says it doesn't know when to expect a reauthorization bill.
A separate law, the massive Water Resources Development Act, would authorize a wide range of Army Corps of Engineers projects, including flood control, shoreline protection, environmental restoration, and work on the Louisiana coast. Cost estimates have varied, but a May report by the Congressional Budget Office projected that the version passed by the House would cost about $15 billion by 2022. A reconciliation bill was expected after the Senate approved the legislation in May.
With or without federal help, local policies can guard against hazards.
"You need good science," says Ken Topping, FAICP, president of Topping Associates International in Cambria, California. "You need good justifications for restrictions. And you need some measurable tools for making some adjustments to the land-use pattern."
For communities that plan an eventual retreat from advancing coastlines, setbacks can be incorporated into the subdivision process. Someday, though, land and water may meet. "Once the shore is up to the setback line, you're back to where you were when you had no policy whatsoever," says James Titus of the EPA.
So-called "rolling easements" are more flexible. Development is allowed, but property owners are told they cannot build anti-erosion structures, Titus says. The property owner is put on notice that he or she may eventually have to yield the right-of-way to an advancing shoreline.
The constant flood
Unwise floodplain development has already caused widespread flood damage nationwide despite technical advances and billions spent on flood control, according to the Association of State Floodplain Managers, based in Madison, Wisconsin. The group says that any new development should use detention storage or other measures to avoid flood hazards.
Property acquisition is one tool a community can use to cut down on risks. A 1995 flood in Topping's small community of Cambria, California, washed out a bridge, isolating part of the town. The community then created a 437-acre park in which recreational trails double as an emergency evacuation route. Community support helped the town pull off an $11 million land acquisition with funds from the state, private donations, and help from a land conservancy, says Topping, former general manager for the Cambria Community Services District (and a former Los Angeles planning director).
Emergency preparedness requires a team approach that includes planners, Topping says. "Planners are going to have to start thinking about contingency planning as part of what they do routinely, and also mitigation," he says.
The task isn't easy, given uncertainty over timing and scope of the impacts. Despite a large array of options, science cannot yet say how effective they will be at fully reducing risks, especially if the fallout is severe, the Intergovernmental Panel on Climate Change has concluded. Further, local restrictions can be politically tricky.
Still, scientists say that adaptation to climate change is unavoidable. Luckily, we have experience with it. A 2004 report by the Pew Center on global climate change notes that adapting to environmental change has been a fundamental part of being human since the dawn of the species.
"Adaptation to the climate changes that lie ahead could be one of the next great challenges to human ingenuity," the report says.
Funding and other help. NOAA: Coastal and natural resource management funding opportunities links are at www.csc.noaa.gov/funding/ natural_resource grants.html. Office of Ocean and Coastal Resource Management are at http://coastalmanagement.noaa.gov/funding/welcome.html. Programs include the Coastal Zone Management Program and National Estuarine Research Reserves.
EPA: Water funding and grants links: www.epa.gov/water/funding. html. Catalog of Federal Funding Sources for Watershed Protection: http://cfpub.epa.gov/fedfund.
FEMA: Grants and assistance programs: www.fema.gov/government/ grant/index.shtm. Pre-Disaster Mitigation Grant Program: www.fema. gov/government/grant/pd.
U.S. Fish and Wildlife Service: www.fws.gov/habitat/ActivitiesList.htm. Includes National Coastal Wetlands Conservation Grant Program.
National Fish and Wildlife Foundation: www.nfwf.org/AM/Template.cfm?Section=Grants. Private, nonprofit organization chartered by Congress.
Restore America's Estuaries: www.restorationmarketplace.com/?id=5. Federal Funding Guide compiled by national nonprofit organization.
See www.iclei.org/usa for the local government guidebook being published this summer by ICLEI--Local Governments for Sustainability.
Reading. Planning for Post-Disaster Recovery and Reconstruction, by Robert Deyle, Charles Eadie, Jim Schwab, Richard Smith, and Kenneth Topping. 1998. APA Planning Advisory Service Report 483/484.
CD-ROMs: Planning for Safe Growth, produced by APA Education and the Lincoln Institute of Land Policy, 2005. Disaster Recovery, produced by APA Education, 2005. Available at APA's PlanningBooks.com.
Fred Ludwig is a Chicago-based freelance writer who covered the environment and the courts as a reporter for newspapers in Utah and California.