James McGowan fondly remembers ice skating every winter while growing up in Flatbush, Brooklyn. It was during the 1950s and 1960s, when his father used to come home from work, spray in the yard and open the DIY trail for all the kids in the neighborhood.
“People were going to ice skate in the city as a regular activity after school,” said McGowan. In the past few decades, he has found it increasingly difficult to skate on the slopes or in the lakes scattered around the city – it just wasn’t cold enough.
Your experience is not just anecdotal. In New York City, the average annual winter temperature has increased by about 3.2 ° F since 1970, according to data from the National Oceanic and Atmospheric Administration (NOAA). And throughout the Northeast, winters are heating up three times faster than summers.
But at the same time, six of the 10 deepest snowstorms recorded in New York City have occurred in the past 20 years – a feat, as snowfall records date back to the 1860s, said Dominic Ramunni, a National Meteorologist. Weather Service in New York. This winter is no different. Nor’easter in early February brought 17.4 inches of snow, and Governor Cuomo declared a state of emergency. The storm was the 16th largest in the city, said Ramunni.
How can there be a harsh winter more often while it is also getting warmer?
Climate change, said Judah Cohen, director of seasonal forecasting for Atmospheric and Environmental Research, a climate risk assessment firm. While it is difficult to attribute any specific climate event directly to climate change, these seemingly contradictory trends can be explained by a warming planet. See how.
Higher temperatures from climate change are causing disruptions in the polar vortex, resulting in a more frequent severe winter in New York City, Cohen said.
The polar vortex is a large area of low pressure and cold air near the north pole and, under normal conditions, the circular flow of air keeps the cold climate concentrated in one area. But according to NOAA, the Arctic is heating up twice as fast as the rest of the planet, and Cohen’s research shows that when the polar vortex is interrupted by warmer air, cold air spreads to other areas of the globe, creating arctic explosions.
“You can think of it as a top,” said Cohen. “You hit the top, start to oscillate, start to meander. And where the polar vortex goes, cold air goes. “
An ice skater entertains a crowd with his hand springs in Brooklyn on January 18, 1923.
Underwood / UIG / Shutterstock Files
Higher temperatures during winter cause the air to retain more water vapor, while evaporation increases in warmer oceans and land. More humidity, more arctic bursts equate to more snowstorms than we’ve seen in recent years.
The result is that snowstorms in the Northeast are decreasing at the beginning and end of winter because of warmer temperatures, but there has been an increase in strong snowstorms in the middle of winter, said Jennifer Francis, senior scientist at Woodwell Climate Research Center, by means of an email. New York is not the only one to feel the effects of the Arctic disturbance, as parts of Europe and East Asia are also affected. This week, Scotland has had the coldest climate in 25 years, according to the Met Office, the UK’s national weather service.
Polar vortex interruptions do not happen every year, said Cohen, so there are still a few milder years like 2020. According to the National Meteorological Service, that was one of the warmest winters on record and about 4 degrees above normal. And when polar vortex interruptions happen, they don’t necessarily last all winter. That’s why we can see warmer winters and an increase in the frequency of harsh winter simultaneously, said Cohen.
Not everyone agrees with the theory that climate change can contribute to disturbances in the polar vortex, a point that even Cohen admits. Amy Butler, a research scientist at the NOAA Chemical Science Laboratory, said by email that she does not think the connection is clear between the weakening of the polar vortex and anthropogenic climate change because the polar vortex naturally has periods when these interruptions occur .
“When we look at future climate change scenarios, there are an equal number of model simulations predicting that the vortex will strengthen in the future … as there are predictions that the vortex will weaken,” said Butler.
The consequences of the harsh winter will not be felt evenly across the five districts. It will probably be more difficult for low-income New Yorkers who rely on public transport, for example. “What we are seeing with all types of disasters, including winter storms, is that impacts are often disproportionately felt in certain communities, in particular non-white communities,” said Andrew Kruczkiewicz, a researcher at the International Climate Research Institute. and Society at Columbia University.
Kruczkiewicz wants to know how far New York City is preparing for a more frequent winter in the future. The Mayor’s Resilience Office, which is responsible for planning the city’s adaptation to climate change, did not respond to Gothamist’s request for comment before publication.
Does all this mean that New York City’s previous weather habits are gone forever, frozen in the memories of outdoor ice rinks? Not yet, Francis said. The region has not made the permanent transition to a new climate zone, but she noted that summers are moving in this way.
New York could move from what is known as a humid continental climate to a humid subtropical climate by the end of the century, unless there is a rapid reduction in greenhouse gas emissions worldwide. This means that, at the end of the century, summer temperatures in New York may look more like those in Juarez, Mexico, according to an analysis by ClimateCentral.
Our final destination is difficult to predict, but Francis says we are likely to see a lot of variability. “As man-made climate change remains unshakable, New Yorkers must expect Mother Nature to have even more tantrums: large temperature fluctuations, heavy rainfall and persistent weather conditions.”
And Cohen said he does not expect the severe winter weather events we are facing now to ease anytime soon. “In the next 10 years, I see no reason for that to change. But after that, we don’t know. “
The weather forecast for New York City for the next week is consistent with this forecast: winter precipitation is expected until Thursday.