CHATHAM — If nothing is done to stem climate change, Chatham won’t look the same by 2050.

“With a two-foot sea level rise...all the marshes are lost, and possibly the south side beaches are gone. It’s pretty serious,” energy and climate action committee member Sarah Griscom told the select board last week. The assessment puts in sharp focus the threats identified by a Cape-wide study the committee presented several months ago.

“The first briefing was sobering,” select board Chair Peter Cocolis said. “This is beyond sobering.”

In response to a global climate crisis, the town needs to take immediate local action, the committee reported. The group is calling for better local planning, more public education and tougher bylaws and regulations to make the town more resilient in the face of rising temperatures and sea levels.

Committee Chair Robert Wirtshafter said residents don’t need to wait to feel the impacts of global warming.

“We’re actually experiencing a lot of this right now,” he said. Coastal storms are stronger and more frequent, causing more rapid erosion of the shoreline. Some salt marshes are already suffering the drowning effects of sea level rise, and higher water temperatures mean more frequent algae blooms. On land, higher temperatures spell less rain and more stress to the aquifer and woodland habitats, which leads to more invasive species. Protecting the town’s natural resources, particularly salt marshes, is a top priority, he said. Not only do they capture carbon and provide protection from storms, “they’re critical to the town’s economic health, particularly fishing and recreation,” Wirtshafter said.

By the end of the century, the Cape Cod Commission projects a $50 billion economic loss to Cape Cod because of climate change, with Chatham footing a $3 billion share of that loss. If climate change’s effects go uncurbed, the town can expect to lose more than half a billion dollars in property tax revenue and $611 million in reduced beach tourism, while declining property values, road and building damage add to the economic toll.

In addition to reviewing studies and data, the energy and climate action committee has interviewed key town staff about what changes they anticipate.

“We have a very good staff of people who are really up on all the issues and the crisis, but in talking to them, they’re overwhelmed by what they have to do right now just to take care of their current situations,” Wirtshafter said. “They’re really not looking at 10 years from now and the sea level rise issues that will be coming.” For that reason, the committee is urging the town manager to create a cross-departmental working group to devise some coordinated solutions, he said.

“And some of these, we’re here to tell you, require urgent attention. Because if we’re going to have any impact at all, we’re going to have to do that now,” Wirtshafter said. The committee produced a detailed hazard assessment with a host of recommended action areas.

“The top four ended up being about marshes and the need for protecting those marshes, because they protect us,” Griscom said. Specifically, the committee recommends revised land use planning around certain waterfront areas.

“We should create a coastal resilience zone and restrict development within these protected areas,” she said. When salt marshes are slowly inundated, they seek to migrate to higher areas. If that land is available for them, they can be preserved. To that end, the town should consider buying certain coastal properties that provide areas for migrating salt marshes, she said.

Griscom said the town should also seek updated information on the effects of sea level rise on Pleasant Bay, building on a report done in 2017. “There’s been some interesting research coming down from the Center for Coastal Studies on the behavior of the outer beach,” she said.

In addition to protecting natural resources, the committee is recommending that the town redouble its efforts to reduce its own carbon footprint, with adoption of even more energy-efficient building code revisions and better infrastructure for electric vehicles. When it comes to the number of residential properties taking advantage of energy efficiency programs funded through Mass Save, “Chatham is among the worst performing towns in the state,” with only about 19 percent of those properties taking part – far below the state average of about 35 percent, Wirtshafter said. “This is an embarrassment to the town.”

Climate sustainability also touches housing, he said. When people cannot find affordable housing locally, they are forced to commute long distances, sometimes from off-Cape communities, and those commuter vehicles add to greenhouse gas emissions.

Select board member Shareen Davis said the cost of addressing climate change is “going to be impactful for our municipality.” She said it’s critical that the issue remain front and center for town government. Board member Cory Metters agreed.

“This is very important to the community,” he said. Metters said the town should establish benchmarks for progress and receive regular updates. When it comes to mitigating climate impacts, the key is “not just acknowledging it, but following through on it,” he said.

The board voiced its support for the committee’s continued work and for its recommendations for immediate action. Cocolis asked Wirtshafter to provide an update in no more than three months.

A storm surge inundates a house on Pleasant Bay. FILE PHOTO