Editor’s note: Nantucket’s 2024 Climate Summit is this Wednesday, Sept. 4. As the island begins implementing the nearly $1 billion projects outlined in its Coastal Resilience Plan, as the town and Land Bank plan a major redevelopment of Washington Street along the harbor, and as private landowners and organizations consider their own responses to climate change and rising sea levels, the Current is publishing a three-part series this week on the impacts of climate change on Nantucket, the island’s response and potential solutions. Read part one below and stay tuned for part two on Wednesday.

The daffodils are blooming too early for Daffodil Day, the hydrangeas on the island were dead and flowerless for most of last summer, and ticks are more prevalent than ever. These may be different problems, but they have at least partly the same cause: climate change.

As an island surrounded by rising sea levels and exposed to increasingly intense storms, Nantucket is particularly vulnerable to climate change. And erosion is not the only issue of concern.

While the effects of warmer air and water are rarely as dramatic as a collapsing bluff or floodwaters gushing down Washington Street, they can be just as worrisome and even more pervasive, affecting everything from fish to flowers. As oceans warm, fish move north, altering populations near Nantucket. And flowers, which often use temperature signals to determine when to bloom, sprout earlier, calling into question the timing of celebrations like Daffodil Day. Cranberries, meanwhile, ripen later—perhaps even too late for the Cranberry Festival—because temperatures take longer to drop in the fall.

Dr. Sarah Bois, director of research and education at the Linda Loring Nature Foundation, knows this as well as anyone. The foundation, she says, has been studying the effects of warmer weather on plants for years. But not because they’re worried about Daffodil Day. There are much more serious ecological problems that arise when plants bloom earlier in the season.

“Every plant has different strategies for getting pollinated and spreading its seeds, and it’s not like it chooses one strategy,” Bois said. Those strategies rely on different pollinators, which may respond to signals that have nothing to do with temperature. If the flowers bloom and the pollinators they depend on aren’t there yet, that’s a problem.

“The relationships that have developed over thousands of years between these species can be destroyed by climate change,” Bois said. “We will not see a species completely wiped out or destroyed. What we will see is diminishing returns for different crops. Species may become less robust and more vulnerable to other threats.”

“We’re seeing such a shift in the way things interact,” added Jen Karberg, director of research and partnerships at the Nantucket Conservation Foundation. “It’s having cascading effects on the ecology of the island.”

One plant that is particularly vulnerable to temperature changes is seagrass. Although it does not rely on pollinators, higher sea temperatures can stress and even kill the plant.

“That’s kind of the big problem because seagrass is a keystone species for this ecosystem,” said Emily Molden, executive director of the Nantucket Land and Water Council. “We’re definitely going to see significant impacts from these rising water temperatures.”

Seagrass slows erosion, reduces flooding and provides habitat for many species of animals, including scallops, making it an important component of the health of Nantucket’s waters. Since 1994, one-third of the island’s seagrass has died. Studies point to many reasons for this decline, including nitrogen from fertilizers washing into the harbor, but one of them is warmer water.

Some species, like the harmful algae that clogs local ponds in summer, thrive in rising temperatures, but they form an uninviting group. Their members include ticks, cockroaches, clothes moths and poison ivy – the latter Bois calls the “superstar” of climate change.

“We’re noticing more certain insects, more certain diseases,” said island landscaper Steven Collette, who works for Ernst Land Design. “There’s always something new to worry about.”

Collette has no doubts about what is causing the increase in pests.

“It’s all related to the fact that it’s getting warmer,” he said. Normally, pests like ticks freeze and die in cold winters. That’s no longer the case.

“We are not losing pest populations as much as we used to,” he said.

Invasive species, many of which posed little threat to their native competitors in cooler climates, also often thrive when temperatures rise. From ivy to broom, invasive species are displacing native species around the island and taking over ecosystems. Lone star ticks, which can cause a fatal red meat allergy in their hosts, may also have migrated to the island as a result of climate change. As their numbers skyrocket, sightings have gone from remarkable to routine. Soon they may be almost as ubiquitous as deer ticks, which thrive even in warmer weather.

However, temperatures do not rise evenly. A warm January can be followed by a cold February, leaving plants unprepared and vulnerable to frost. These are the very events that damaged so many hydrangeas on Nantucket last year.

Precipitation follows a similar pattern. Nantucket has experienced several severe droughts in recent years, which have increased the risk of dangerous wildfires and destroyed some sensitive plants. Overall, however, precipitation on the island is actually increasing. It’s just that the precipitation is not falling evenly throughout the year, but all at once.

“We have drought, drought, drought, and then our soils are dry. And then we have a significant rain event in the winter, maybe a northeast storm or something like that, where we get a whole lot of precipitation at the same time,” Bois explained.

This is the perfect recipe for a flood. The water can’t penetrate the ground fast enough, so it fills the streets and pours into basements. And because the ground is dry and loose, the water carries huge amounts of debris with it, massively increasing erosion as it eventually flows into the sea.

From floods to droughts, flowers to fish, climate change is affecting nearly every aspect of life on Nantucket. While these impacts are invisible and occur slowly over decades, they are still transforming the island.

“Everything,” said Karberg, “is just getting a little more extreme.”