In Old Saybrook last week, a newly formed municipal panel met for the first time to contemplate how to help this low-lying coastal community cope with what one member likened to a natural disaster happening in slow motion.

"I see sea level rise for Old Saybrook as being the most important natural hazard," Sandy Prisloe, the town's environmental planner, told the 12 other residents and town officials gathered Thursday for the first meeting of the Sea Level Rise Climate Adaptation Committee. "Future storms will create more and more damage. How can we be proactive to mitigate problems down the road?"

Committee members shared personal experiences with flooding at their waterfront homes during Tropical Storm Irene and Superstorm Sandy, saw maps showing 30 percent of their community could be swamped the next time severe weather strikes, and considered the financial and social costs of inaction.

"If we lose 30 percent of our town, this town would be vastly different. This isn't just a coastal issue," said Roger Yust, who works as an engineer and planner at the Naval Submarine Base in Groton. "We're not going to be able to just build our way out of this."

Walter Smith, Conservation Commission chairman and acting chairman of the new panel, said the group's charge is to work for the next year on actions the town should take to handle the rising waters. The group would then take the recommendations on a six-month "road tour" to educate all parts of the community about it. After that, it would be up to town officials and residents to implement the steps.

"We want to make sure this town is viable and sustainable 20 years from now," he said.

Coincidentally, the panel's first meeting came just two days after release of the National Climate Assessment, a federal report examining current and predicted impacts of climate change, including sea level rise and increased flooding.

Combining the work of 300 scientists and other experts along with 13 federal agencies, the report is divided into sections examining impacts and challenges for 10 different parts of the country. It emphasizes the need for the entire nation to reduce fossil fuel emissions, the main source of carbon dioxide buildup that is in turn the main cause of climate change.

Its conclusion, said Don Wuebbles, professor of atmospheric science at the University of Illinois and one of the lead authors, is that "climate change is happening now, and the evidence gets stronger all the time." Wuebbles and other authors spoke to reporters during a conference call Tuesday.

Radley Horton, research scientist at Columbia University, was one of two convening lead authors of the chapter on the Northeast. One of the main challenges for this populous, highly developed region, he said, is the vulnerability of its aging infrastructure, including large sections of major transportation corridors such as Interstate 95 and the Amtrak rail corridor that sit in flood-prone coastal areas.

Sea level along the North Atlantic coast has risen about 1 foot since 1900, according to the report, as land-based glaciers melt and water molecules expand with warming average temperatures, pushing marine and river waters ever farther inland.

Sea levels are projected to rise an additional 1 to 4 feet by 2100, the report notes, with the increase in the coastal Northeast exceeding the global average.

Horton noted that the region is also experiencing more frequent intense rainstorms that further increase flood risk. Between 1895 and 2011, average annual rainfall rose by about 5 inches, or more than 10 percent, the report states, and about 70 percent of that increase came during heavy downpours that saturate floodplains and overwhelm drainage systems, he noted.

As apocalyptic as the report's findings may sound, he added, he remains hopeful that the nascent efforts of communities across the Northeast will gain momentum.

"The vast majority of climate action plans and mitigation strategies are at early stages," he said. "But there are opportunities for us to reduce greenhouse gases and to adapt."

Change at state,  local levels

In Connecticut, examples of these first forays can be found at statewide and local levels, from the new panel in Old Saybrook to revised road and bridge design standards being used by the state Department of Transportation to incorporate new flood and storm data.

That is influencing how a new bridge over the Yantic River at Sherman Street in Norwich is being designed, said Barry Ellison, the city's public works director. The $7 million project would replace two spans originally built more than 50 years ago.

"The increased frequency of flooding is certainly being considered in the six or seven alternative designs being contemplated," he said. "The water has been up against the bottom of the bridge three times in the last 10 years."

Adam Whelchel, a lead author of the Northeast section of the report, is also director of science at the Connecticut chapter of The Nature Conservancy. Over the last three years, his organization has been working with towns along the Connecticut coast to help them understand and prepare for climate change effects, creating a Web-based tool that maps where rising seas would encroach. It has also helped to identify and protect tidal marsh areas for protection and expansion inland, such as Barn Island in Stonington. Marshes preserve important natural habitat and act as buffers against flooding in residential and commercial areas.

"There is a growing awareness of what the risks are," Whelchel said.

Communities including East Lyme, Stonington borough, Waterford and Old Lyme are starting to factor climate change into their decisions about future investments in everything from culverts to pump stations to dune restoration, he said.

"But as far as hard-core projects, on-the-ground stuff, we're still light on action," he said. "We're still in the planning phase."

Most of the attention thus far, he added, has been given to the hazards of intense storms, sea level rise and flooding. Towns also need to focus on the threat of more frequent and prolonged heat waves, as well as the public health implications of climate change, such as higher pollen counts that exacerbate asthma and infestations of Asian tiger mosquitoes that carry West Nile virus, Whelchel said.

At the state level, the Connecticut Climate Change Preparedness Plan has been in place since 2011. Last summer, the state Department of Energy and Environmental Protection began working on a list of action items to make the state more resilient to severe storms. Among the initial actions to come out of the effort is the formation of the Institute for Community Resilience and Climate Adaptation at the University of Connecticut's Avery Point campus in Groton. Announced in January, it will help municipalities, businesses and homeowners prepare for climate change impacts.

Juliana Barrett, extension educator at Sea Grant, also at Avery Point, said a key project is the creation of a coastal hazards website. Communities will be able to use the site to better withstand future intense storms, she said.

"We hope to have it ready by the end of this summer," she said.

Another response is the creation of Stormwise, a partnership of power utilities, the U.S. Forest Service and UConn's Department of Natural Resources. Thomas Worthley, associate extension professor at UConn, said Stormwise came together after the severe storms of 2011 and 2012 to determine how the state can maintain its landscape yet reduce the incidence of power outages caused by fallen tree limbs.

"There are three basic ideas," he said. "A tree that has space to grow will be healthier. Trees tend to grow towards the light. And if a tree is allowed to move in the wind, it develops wind firmness."

Research is taking place at the UConn forest in Storrs and two other sites to determine optimal tree spacing, how trees move in the wind, and the mix of tree sizes and species best suited to roadsides, Worthley said. The overall goal, he said, is to enable the state to co-exist better with its trees, which are a highly efficient and ever-more-necessary means of capturing carbon dioxide from the atmosphere.

"We envision building a community culture that embraces the idea that we do have to manage the land," he said. "And if you have a healthy forest that's growing, it's going to capture more carbon."

Funding a limitation to changes

At the Southeastern Connecticut Council of Governments, which represents 22 communities, climate change issues are becoming a more frequent topic, said James Butler, executive director. One key obstacle, he said, is finding the money for the planning and upgrades needed.

"The conversations are happening," he said. "But funding is going to be a huge limitation."

In 2012, the council updated its Natural Hazard Mitigation Plan as required by the Federal Emergency Management Agency, with each town writing its own section. In the executive summary for the plan, flooding is identified as "the primary hazard in the region."

"It talks about flooding and how to mitigate it," Butler said. "We know floods are becoming more frequent due to climate change."

Old Lyme, which is part of the Lower Connecticut River Valley Council of Governments, is in the midst of updating its Natural Hazards Mitigation Plan. A draft copy released in March mentions sea level rise, loss of tidal marsh habitats and flooding as major concerns.

It recommends the town pursue purchase of vacant lands prone to flooding, relocate vulnerable critical facilities, better manage stormwater, elevate roads, help shoreline homeowners raise structures out of floodplains and update planning, zoning and building code regulations to account for rising sea levels and floodwaters.

Similar recommendations were made in a 2011 report in Groton. Deborah Jones, acting director of planning in Groton, said that report and a growing awareness of climate change are influencing town decisions and are being incorporated into an update of the town's plan of development and conservation.

"It's part of everybody's plans," she said.

One example, she said, was the town's purchase of property adjacent to tidal marshes on Thomas Road just over a year ago. One of the main arguments made for the purchase, she said, was the need to keep the land as open space so the marshes could migrate inland with rising seas.

The Nature Conservancy's Whelchel said that while thinking about and planning for the impacts of climate change are an essential first step, there is no time for foot-dragging once decisions are reached.

"The longer we wait, the greater the consequences will become, both socially and economically," he said. "Climate change is not something in the future. It's here now. If we ignore it, it's at our own peril."

j.benson@theday.com