As New York City gets hammered with another blockbuster snowstorm, one that could end up in the top-five snowstorms – the inevitable question arises – how do these massive snow dumps happen as the planet is warming due to climate change?
And if it seems like we are seeing more of these blockbuster storms, especially along the East Coast, it's true.
Once this storm drops its final flakes, it will almost certainly make six of the top-10 largest snowstorms in New York City history occurring in the past 15 years. With 150 years of records in the books, one would expect to only have about one top 10 storm in the past 15 years if things were distributed evenly.
This is a trend that is playing out in much of the country and is an expected consequence of global warming.
"The frequency of extreme snowstorms in the eastern two-thirds of the contiguous United States has increased over the past century, according to NOAA, and "approximately twice as many extreme U.S. snowstorms occurred in the latter half of the 20th century than the first."
There are several reasons for the increased snow totals, with the main ones being warmer-than-normal ocean temperatures and added moisture available in the atmosphere.
Warmer air can hold more moisture, and warmer oceans allow for more of the moisture-rich air to enter the snowstorms. The same principle is responsible for larger rainfall totals and increased flooding in hurricanes and summertime storms.
While individual snowstorms may have larger snow totals in a warming climate, especially along the coasts, this does not mean winters are seeing more snow overall. Most locations are expected to see less snow, on average, during winters in the future.
This trend has already been observed with shorter snow seasons and more winter precipitation falling as rain across much of the country.
Looking at the same New York City snow history, even with six of the top 10 biggest snowstorms coming in the past 15 years, the annual snowfall average has dropped from around 31 inches/year to about 25 inches/year in those 150 years.
So, in short, climate change means less snow overall — but more comes in quick bursts.