Extreme flooding in Montpelier, Vt., in 2023. Photo by Vermont Agency of Agriculture, Food and Markets via AP

Climate Change

Algae, Disease-Bearing Ticks, Erratic Snowfall, Tainted Oysters, Costly Insurance, Extreme Temperatures—Is Climate Change Ruining Our New England?

Boston University scholars in environment, public health, marine science, and more weigh in. “The scale of what we are signing ourselves up for is unprecedented,” one says

Climate change is here, all around us, affecting the four seasons that define New England’s identity and the activities we anticipate as the weather changes throughout the year: fall foliage and leaf-peeping. Quiet walks in the woods. Skiing down slopes of fresh powder. Swimming in beautiful lakes and at ocean beaches. Jogging along the Esplanade. Downing a dozen oysters at the end of a summer afternoon. 

These climate change trends that affect us directly also portend deeper changes. Declining snowpack doesn’t just cut into our skiing or winter hikes—it affects spring snowmelt and water supplies. Stress on forests affects more than fall foliage—it means forests may store less carbon from the atmosphere, at a time when we need it the most.

And if you’re worried about more hurricanes hitting your state or more floods in your town or more ticks bearing disease in your yard, those issues can become chronic stressors. Climate anxiety is just as real as climate change, and it can affect your mental and physical well-being.

It’s all happening because heat-trapping greenhouse gases, such as CO₂ from humans burning fossil fuels, are warming the planet. Climate scientists are near unanimous in saying we are heading for disaster unless we make profound changes to the way we live. 

Climate change deniers say it’s all a big hoax. President Trump says, “the ocean’s going to rise one-eighth of an inch over the next 400 years” and will bring us “more oceanfront property, right?” (Scientists say it’s more likely that his Mar-a-Lago resort in Southern Florida will see its manicured lawns regularly flooded within 30 years.) Even some who acknowledge the threat think its biggest effects will be felt elsewhere—Pacific island nations like Fiji, or Africa, or California—rather than New England.

But in fact, sea levels are rising in the Northeast, while storms and high tides gnaw at our coastline. And the changing seasons New Englanders know and love are growing increasingly erratic and blurring together in ways never seen. 

“The impacts of continued climate change are really different in Rhode Island, which has 400 miles of coastline at risk [for] sea level rise, versus Vermont, which doesn’t have any coastline, but where inland flooding is happening more often,” says Gregory Wellenius, director of the BU School of Public Health Center for Climate and Health, and an SPH professor of environmental health.

“Change is the constant, but the scale of what we are signing ourselves up for, and the speed, maybe is unprecedented,” adds David Demeritt, a College of Arts & Sciences professor of Earth and environment.

Climate change impacts the world. But here in New England—where our seasons shape how we live, where we brag about our proximity to mountains and oceans, to skiing and swimming—it’s being felt in very particular and meaningful ways. We asked BU scholars, in fields ranging from Earth and environment to public health and disease to marine science and biology, to describe what’s going on right now in New England—and where it’s heading.

The seasons and foliage

“Spring is starting earlier,” says Michael Dietze, a CAS professor of Earth and environment who leads BU’s Ecological Forecasting Laboratory. That means winter is ending sooner, offering less time for skiing or sledding, but more time for biking outdoors or gardening.

“The bad years are getting worse; increasing annual variability in climate is driving increasing variability in ecosystem responses.”

Michael Dietze

Photo via Unsplash/Peter James Eisenhaure

“It’s of sufficient scale that it’s often expressed in terms of days per century; now it’s like three or four days per decade,” Dietze says. “So maybe on the order of half a day per year, which, you know, adds up pretty quickly. In just my time here at BU, that would be a whole week earlier.”

Dietze has helped launch the Ecological Forecasting Initiative, a grassroots organization bringing together researchers, decision-makers, and other stakeholders to improve predictive science. “Much of the imperative to focus on ecological forecasting comes from the need to respond to the multitude of environmental problems facing society and the aspiration that environmental decisions be made with the best available science in hand,” its mission statement says.

Climatewise, “the bad years are getting worse,” Dietze says. “Increasing annual variability in climate is driving increasing variability in ecosystem responses.”

Fall is changing just as much, but more erratically, which can be influenced by a wide variety of factors, including temperature and moisture, the scientists say. “Spring leaf out is a much better understood process than leaf fall,” Dietze says. “The autumn leaf fall is much more variable and harder to predict from year to year.

“Our traditional whack of color at some point in October could at least be much more spread out, and could be harder to predict,” he says. “You’ll have more variability where some years are quicker and some years are more gradual, depending on the climate variability.”

Fall foliage brings in significant tourist dollars and is anticipated by residents every year. But foliage is “really sensitive to environmental conditions,” says Pamela Templer, a CAS Distinguished Professor and chair of biology, whose work focuses on environmental change.

“As you know, we have leaf peepers, people driving up from New York City and elsewhere. It’s iconic. So anything that changes that is going to have an impact on the economy,” she says.

“If the trees are super-stressed, they’re likely to drop their leaves early, and not give us the vibrant colors that we expected.”

Pamela Templer

Photo via Unsplash/Jeff Mako

“If you’ve had an extreme drought, if you had extreme rain, if you had a pest outbreak—it’s hard to say. There’s so many different factors,” Templer says.

“There’s a sweet spot there, and we can miss it on either side, due to climate change.”

Different forests, new pests

In terms of forest health, “New England is actually getting off easier than most everywhere else,” says Dietze. “In the West, you have gradual climate change and you have forests that have been decimated by wildfire, decimated by drought. Forest survival is a question out there. The thing that’s coming back after a forest is a shrubland, or a grassland, or something like that.” 

The forests here are changing, just slower. 

“Hemlocks are kind of iconic,” Dietze says. “These big evergreen trees with little needles, and they tend to be large stems very well spaced out. When you’re among them, they’re just beautiful forests.”

But hemlocks are threatened by the hemlock woolly adelgid, a destructive insect that arrived in North America from Japan in the 1950s and has now followed the warming climate as far north as Maine and Nova Scotia. It sucks the sap out of the trees, drying them up and stopping new growth, eventually killing many. Typically the hemlocks are replaced by faster growing birches. 

“It’s going to be a hardwood forest instead of a conifer forest,” Dietze says, “and it’s going to have a very different feel to it, which affects not just people walking through it, but also the birds and amphibians and animals that live there.”

“Birches take up a lot more water, so that dries up local streams and has cascading effects on animals like salamanders,” says Templer, whose lab focuses on the effects of environmental change on carbon, nitrogen, and water cycles in ecosystems. “You change what lives there, you change what’s happy there. So yeah, our ecosystems are going to change.”

One of Dietze’s graduate students is studying a spongy moth (Lymantria dispar dispar), formerly known as the gypsy moth. In its caterpillar stage, the spongy moth eats the leaves of many species of trees and plants, decimating forests. Its population had been successfully managed with biocontrol agents, including a fungus. But in 2016 and 2017, New England saw its first major outbreaks in three decades.

“We’ve been able to show that drought, and particularly multiyear dryness, is a strong predictor of spongy moth outbreak,” Dietze says. “Attributing it is a challenge, though, trying to figure out how much of that is due to trees being stressed, and how much of that is due to the caterpillars and larvae being able to survive due to mild winters, and how much of that is the drought affecting the survival of the biocontrol agent.

“But we can definitely say that if you have milder winters and dry springs and dry summers, that you set yourself up for a greater likelihood of a spongy moth outbreak. Which is very damaging to the tree stock.”

“There will be winners and losers in forest composition,” Templer says. “We’re worried about our beech trees, with beech leaf disease coming in.”

Beech trees, “a huge presence” in New England’s forests, have survived beech bark disease for many decades, Templer says. But beech leaf disease appears to be different. Within a few years of infection, the trees die, and there are no saplings. “It’s too early to say it’s climate change–related, but that’s the fear,” she says.

“If we lose this species, people don’t realize. You’re going to be driving up I-90, and you’re going to see barren areas or the understory of the forest just gone.”

Pamela Templer

Photo by Mikhail Peace

She says the disease has already been spotted in every town and city in Massachusetts and New Hampshire: “And these kinds of things are likely to increase over time as it gets warmer.”

Mosquitoes, ticks, and disease

“Let’s start with mosquitoes,” says David Hamer, a School of Public Health professor of global health and a Chobanian & Avedisian School of Medicine professor of medicine.

With a longer warm season, mosquito season can start and last longer, Hamer says, increasing the risk of diseases, like West Nile virus and eastern equine encephalitis, that are already here. But that’s only part of the problem as New England’s climate warms.

“What fascinates me is the progressive march north of Aedes albopictus, the tiger mosquito,” says Hamer, who is colead for climate change at the Center on Emerging Infectious Diseases. “This is a species that is competent to transmit dengue fever, chikungunya, Zika, and potentially other [of] what we call arthropod-borne viruses, or arboviruses.”

Last year, Hamer was contacted by the media when there were 40 cases of dengue fever in Massachusetts, but eventually it became clear that these were all people who had been to the tropics and caught it there. But the insects are “definitely moving northward,” Hamer says. Recently, the Massachusetts Department of Public Health has identified tiger mosquitoes in two different areas in the state. It has also been found in Vermont, though not yet in Maine or New Hampshire, he says.

“It is just a matter of time,” Hamer says. “The risk for introduction and spread of these viruses is progressively increasing, and this is a direct effect of the Aedes and the changing climate that allows it to develop.”

Then you have ticks.

“Tick-borne diseases are a complex story,” Hamer says. “It’s somewhat influenced by climate, but it also is a function of the white-footed mouse and deer populations. The mouse is sort of a natural host for procuring the ticks, but they can jump to deer, and the deer and mouse ranges have expanded. That means that the ticks are moving further north.”

Lyme is by far the most common tick-borne disease, but the risk of anaplasmosis and babesiosis has expanded throughout New England and New York State, Hamer says. Maine collects ticks across the state and analyzes them for all three of those diseases, as well as other, much less common illnesses, like Powassan virus.

“There’s a lot more disease or a lot more affected mosquitoes in the South, but you find it all the way up to the top of Maine now, and I don’t think that was the case 20 years ago.”

David Hamer

Photo by Jimmy Chan

One of Hamer’s patients got babesiosis working in his backyard in Jamaica Plain. In Massachusetts, historically, babesiosis was found primarily on Nantucket, Martha’s Vineyard, and a bit on Cape Cod, Hamer says. Now “it’s definitely more widespread in Eastern Mass, and Connecticut. And probably Rhode Island, as well. And so we are putting that down to the changes in tick lives that we are talking about.”

Even more mundane ailments are getting worse because of climate change, Dietze says. “One question about a longer growing season with an earlier start is, ‘Is there more pollen in the air?’ It’s thought that people with allergies are having a tougher time now.”

Snowfall is down 

“Skiing is getting increasingly unreliable,” Dietze says. “This winter has been so bitterly cold that I actually have skied in Mass, but that is a clear anomaly relative to many years of very mild winters.”

And even this year’s cold winter is not inconsistent with global warming, Dietze says, because higher year-to-year variability is actually predicted by climate models.

“Before that, I can’t remember the last time I was actually able to ski in Massachusetts,” he says. “You have to drive all the way to Maine, and even there, there’s not reliable snow.”

“We went up to Maine for New Year’s last year, and there was basically nothing to ski on.”

Michael Dietze

Photo via iStock/WoodysPhotos

“Long-term measurements of seasonal snowpacks indicate increases in mid-winter snowmelt and earlier snowpack disappearance in the northeastern U.S.,” was the title of a December paper in the journal PLOS Climate, echoed by many others. The Boston Globe reported recently that New England winters are now three degrees warmer than during baby boomers’ childhoods, and our winters are warming twice as fast as summers.

There will still be snowstorms and even snowy winters, but the trend is downward. And that’s bad for the ski industry.

“What is happening in the ski industry is a visible regional example of the physical risks of climate change, which businesses in virtually all industries are confronting in some capacity,” says Sarah Armitage, a Questrom School of Business assistant professor of markets, public policy, and law.

The industry brings in billions of dollars and creates many seasonal jobs in New England. 

“Climate change and its anticipated impacts pose a significant threat to the current and future stability of the ski industry across New England,” according to a University of New Hampshire study. New England has lost hundreds of ski areas in the last few decades, especially smaller ones—although how many are directly attributable to climate is unclear. Resource-intensive snowmaking is ever more important, but even that depends on the weather being cold enough. 

“The declining snowfall has big consequences across New England, not just for people’s ability to go skiing, but also hugely for the economies of the many communities across the region that depend on people looking for winter recreation,” says Wellenius. “There are also health consequences for that. People don’t have money, they don’t buy the same food. Maybe they drink more. Maybe there’s more domestic violence. And you’ve got to think the economic stress leads to mental health consequences.”

Similarly, warming summertime temperatures lead to more algal blooms and more frequent closure of beaches or fisheries, and so threaten the economic well-being of many seasonal communities, he says.

“The impacts aren’t just economic, they threaten the health and well-being of people across the region,” Wellenius says.

“Kids of 20 or 30 years ago used to be able to depend on snow days to look forward to and get excited about, and now they’re not getting many.”

Pamela Templer

Photo via Unsplash/Andrew Spencer

“That’s a bummer. I know it’s like, the world moves on,” Templer says. “But that’s a real thing that’s changing, another part of the story that we like that’s being taken away.”

Maple syrup season

“Maples are one of our most iconic groups of species, right? We get maple syrup from them, and they’re beautiful in the fall, so they’re very highly valued here in New England,” Templer says. “But their roots are really at the surface of the soil. Now, all of a sudden, we’re not getting as much snow, and they’re more exposed to the freezing air temperatures, so they themselves freeze.

“And in all of our research we’ve shown that they don’t like to be frozen in winter. They get damaged more than other species. They don’t take up as much nutrients, like nitrogen or phosphorus.”

Studies by the University of Vermont and others show that climate threats to maple producers range from extreme storms to erratic frosts and early warming that can prematurely stop the sap run. Long-term health of the tree population affects the industry’s future.

Templer says that’s bad news since forecasts assume the forests will be there in the future to help slow warming. “And what we’ve documented is that just changing the winter climate alone will reduce how much carbon they take up in the next growing season by up to 40 percent,” she says.

Oceans and oysters

“Over the last few decades, the waters off the coast of Massachusetts have warmed more than almost anywhere in the world,” according to the November 2024 report “Climate Change Impacts on the Marine Environment in the Greater Boston Area,” by the Marine Environment Team of the Greater Boston Research Advisory Group. “This warming is expected to continue over the next 30 years, with an additional surface warming of 1 [degree Celsius] to 2.5 [degrees Celsius] across most of the domain by 2050 and up to 4 [degrees Celsius] by 2100.”

“Over the last few decades, the waters off the coast of Massachusetts have warmed more than almost anywhere in the world.”

Marine Environment Team of the Greater Boston Research Advisory Group

Photo via Unsplash/Ozzie Stern

“The phrase we always use is that it’s going to be a very different environment,” says Marine Environment Team leader Bruce Anderson, a CAS professor of Earth and environment, whose research includes global and regional climate change and large-scale ocean-atmosphere interactions.

The team studied marine environments from the nearshore tidal flats and coastal waters to Georges Bank and the Gulf of Maine, as well as how the environments depend on larger ocean systems, including the Gulf Stream and the Labrador Current. The most immediate effect they’re already seeing is on marine life.

“We’re seeing a large shift, with more species from the mid-Atlantic. They’re being caught particularly south of the Cape, but also in the Gulf of Maine,” Anderson says. “We’re starting to see blue crab, which means our waters are as warm as Maryland, effectively. And we’re seeing a large migration out of the region of cold-water species—cod, for instance—which are moving further north and being caught further north. Same with lobster.”

In the long run, these changes can disrupt the fishing industry, or at least cause it to pivot. But wait, there’s more for seafood lovers to worry about. Mussels and other shellfish can be adversely affected by the acidification of seawater caused by the ocean absorbing increasing levels of carbon.

As warmer ocean temperatures have spread farther north, so has the potential for problems with local shellfish.

“There are certain ocean temperature ranges that are ideal for Vibrio,” a bacteria in shellfish that can cause a severe gastrological illness, says Hamer. Varieties such as V. parahaemolyticus grow naturally in the ocean, but thrive in warmer waters and can affect clams, mussels, and oysters. 

“Those Wellfleet oysters that we always thought were safer than the Gulf oysters may not be anymore,” Hamer says.

“A couple of years ago, for the first time they had Vibrio infections in the state of Washington, and the same thing’s been happening on the East Coast. You’re finding it much further north,” Hamer says, including in New York, Connecticut, and Massachusetts. And besides getting possible illnesses from contaminated shellfish, if people have direct contact with water and have a wound, the bacteria can get into the wound and cause a pretty nasty infection.

Wildfires

Climate change has stoked disastrous wildfires in California and other western states for years, by alternating torrential rainfall that produces plenty of vegetation with droughts that turn that vegetation to dry kindling. Red flag warnings go up, and too often a spark ignites a deadly conflagration.

Smoke from wildfires in Canada affected the air quality over New England a couple of times recently. But the region has largely avoided the fire threat until the drought season of fall 2024, when numerous brush fires erupted in Massachusetts. More acres burned in the Bay State (almost 4,000) than in the previous two years combined. Few areas have done much preparedness planning, Demeritt says.

Fortunately, the biome of most of New England’s forest is different than in the ones out west.

“For the most part it’s generally pretty wet,” says Demeritt, whose research focuses on environmental policy, in particular the management of flooding, wildfire, and other environmental risks. “The deciduous vegetation around here is pretty soggy. Even the spruce-fir forests of northern Maine are pretty damp. It takes some doing to kind of dry them out enough to really burn them.”

He says that “nobody around here remembers a year like last year, with heat and drought.” Still, as the climate warms, that “hydrological whipsaw of wet years and dry years, there’s some suggestion [fires] are going to become more common. It’s not like California and the Southwest, where you’re looking at decades-long droughts, but it will become more of a problem. And I think it’s a problem that is not on a sufficient number of people’s bingo cards around here.”

Climate-induced insurance woes

The one industry that might feel the biggest impact from climate change is insurance—which directly impacts everybody’s pockets. This winter’s California wildfires could cost insurance companies $10 billion, “threatening to upend an insurance market that is already under profound financial strain,” according to the New York Times. In New England, the problem is water.

“The home insurance industry has really been bleeding money, and not just for the big perils they know about and buy reinsurance for—like hurricanes in Florida and wildfires in California—but, like, really intense convective rainfall and hailstorms in the Midwest,” says Demeritt. “New England has been about the only region where they’re not losing their shirts.”

But rainstorms and related flooding hit hard in Vermont in 2024. Monthly nuisance flooding from king tides in the downtown Boston waterfront, and from shore roads up and down the coast, predict bigger problems for many low-lying areas, including much of downtown Boston and the Seaport. The wolf is already at the door, where rising oceans and more intense storms have been threatening and sometimes destroying waterfront properties from Plum Island to the elbow of Cape Cod.

“Everyone wants to live at the beach, [but] insurers are alive to this and it is going to start to get much more expensive and potentially quite difficult [to insure those properties.]”

David Demeritt

Photo by David Kanigan

“Insurance companies have increased premiums and many of them have managed their own risk by not providing coverage. They’ve moved away,” says ​​Mark T. Williams, a Questrom School of Business master lecturer in finance, specializing in risk management.

Basically they have exited from certain states or regions, particularly high-risk zones along the coast. What they consider to be “uninsured zones,” Williams says. “And that’s created a new risk, as it’s forced states to fill this void and reluctantly become the insurer of last resort.”

Where they are still writing policies, “because of climate change, natural disasters have become amplified, not only in frequency, but also in severity of dollar loss,” Williams says. “And with less insurers willing to insure, and event probabilities rising, premiums have skyrocketed.”

Williams tells the story of one coastal homeowner in Rhode Island who was surprised by a 15 percent premium increase for last year. So the homeowner shopped around to four other insurance companies. Two said they wouldn’t insure the property at all. And two said they would write a policy—for double what the homeowner was currently paying.

The problem of getting affordable insurance, or any insurance at all, is catching up with Massachusetts homeowners the way it has already caught up with many in California and Florida, Williams says. And it’s not just at the coast. Last year’s torrential rains and recurring flooding in Vermont may mean that homeowners in places like Montpelier may face the same issue.

“Eventually insurers will just say, ‘Enough. We’re not paying.’ And so you can have your million-dollar beach home, but don’t count on financing it with a mortgage,” Demeritt says.

For well-off New Englanders, that means you buy the second home knowing full well that it might fall into the ocean one day, and you’d have to eat the cost and go on living.

“If you have sufficient cash resources,” Demeritt says, “and it’s a wealthy country, you can just treat your beach home as a consumable.”

In other words, enjoy it while it lasts.