What's behind New York fires? Climate change, land use and history

Enjoy complimentary access to top ideas and insights — selected by our editors.

(Bloomberg) --Wildfires that are raging across New York and New Jersey highlight a new threat to one of the world's most affluent regions. 

Climate change is regarded by scientists as the pre-eminent factor driving long-term changes in weather, and the New York region is experiencing a severe drought — the Big Apple experienced its driest October on record. Dry, hot weather underpins fire danger across the globe today. 

The blazes also have their roots in issues that are a century or more in the making: Evolving land use and a stew of invasive plants, insects and diseases have combined to transform the natural landscape, leaving it ready to burn.

While small compared with many of the wildfires that regularly devastate the US West, the blazes in the Northeast are increasing risks in one of the most densely populated parts of the country that also boasts some of the priciest real estate in the world. The fires have sent plumes of smoke skyward visible from Manhattan and have raised breathing risks from New England to New Jersey. 

A fire currently raging across New Jersey's Passaic County and New York's Orange County had consumed 5,000 acres, closed roads and was just 10% contained as of Tuesday evening, according to an update from New York Governor Kathy Hochul's office. The blaze is one of 537 that New Jersey's forest fire service has been called to respond to since early October—a 1,300% increase over the same period last year. In response, New Jersey officials issued a statewide drought warning Wednesday, urging residents to conserve water for firefighting efforts. 

Hochul said in an X post on Tuesday afternoon that New York State was managing 11 confirmed wildfires, as a blaze in the Bronx Tuesday halted Amtrak service between Penn Station and New Haven, Connecticut, and caused disruptions on the Boston-New Haven route. Amtrak said in an advisory that service was still suspended as of 2 p.m. local time Wednesday, with no estimates for when tracks would reopen.

And brush fires broke out in at least two New York City parks: Inwood Hill Park in upper Manhattan and Brooklyn's Prospect Park, near the upscale Park Slope neighborhood. The Inwood fire was reported around 2:30 local time Wednesday, according to the New York City Fire Department, which deployed 45 fire personnel to extinguish a "large area of brush."

A fire reported last week in Prospect Park was brought under control, but Mayor Eric Adams said fighting the blaze was difficult because the wind blew around burning leaves. The fire department used drone technology to identify hotspots.

The origins of the transformed landscape date back to before the Civil War, said Mark Ashton, senior associate dean of Yale University's Forest School. In the 19th century, most of the US Northeast was almost completely cleared for agriculture. When farming shifted to other parts of the country, the abandoned land began to reforest from 1850 to 1900. The landscape is now thick with a lot of 100-year-old trees and very little plant diversity.

That made worse fire threats that were sparked by this year's dry weather. 

A summer and fall of drought and dry winds pushed through the region, and now there is "near to record-setting high fire danger," the US Storm Prediction Center warned. That risk extends from Massachusetts to New Jersey and is forecast to linger in the coming days. 

No Rain

In recent weeks, the skies have squeezed out almost no rain, leaving the nearly 94% of the land from Maine to West Virginia abnormally dry and leading to one of the widest droughts across the Northeast since 2002, according to the US Drought Monitor. In the 12 Northeast states on the Drought Monitor's map, more than 56% of the land is in drought. Parts of New Jersey, New York, including Long Island, Pennsylvania and Connecticut, had a record dry October, according to the US Centers for Environmental Information. 

Read More: Climate Fight Is Failing to Hit Its Deadlines, Now Comes Trump

The older trees that blanket the landscape are prone to sucking water out of the ground, which can make droughts worse. 

On top of that, the climate in the Northeast US is very similar to parts of Asia and Europe, so invasive plants and their hitchhiking insects and diseases are able to thrive in the region. That's an issue that's plagued the area all the way back to the early days of the Industrial Revolution. Its location and its history have made "the Northeast is the epicenter for invasive insects and plants," Ashton said. 

When humans first arrived in the Northeast, the land was covered with ice and was mainly a tundra. Then forests came later. People's attitudes about fire changed in the late 19th and early 20th century, when it was viewed not as a tool to clear dense forest, but as a threat to homes and property.

Adding to these issues is that Earth itself has warmed, which has led to a situation where rain events have become more intense — but also spread out over time. The Northeast typically was a region where rain was steady and plentiful, but in recent years drought has become more common.

 "There is a climate-change effect of more precipitation, with interludes of long periods of drought," Ashton said.