Experts study global warming concerns after Juno
In the wake of the underwhelming winter storm Juno that just passed, the wrongly predicted weather event sparked a discussion about how global warming impacts weather and consequently, other environmental concerns such as agriculture.
Global warming involves the output of greenhouse gases into the atmosphere, where these gases trap heat acting like a blanket to slowly warm the planet.
Global warming increases the environment’s warmth and moisture, especially over the oceans during storms, said Kevin Trenberth, a distinguished senior scientist in the Climate Analysis Section of the National Center for Atmospheric Research.
Trenberth said this phenomenon makes for heavier precipitation, which causes stronger but possibly fewer storms with longer gaps in between.
Future weather predictions are hard to tell because of variability, Trenberth said. Important components of this are the El Niño and La Niña. Both are part of the El Niño-Southern Oscillation Cycle, according to the National Ocean Service.
The ENSO Cycle is a scientific term that describes fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific, according to the NOS.
The NOS site says El Niño and La Niña occur every three to five years and can last from nine months to years. During El Niño, unusually warm waters in the Pacific cause warmer winters — La Niña is the opposite.
“This past year has been one of a weak El Niño,” Trenberth said. “This goes against the expected big El Niño that was supposed to happen after the last one a few years ago, which emphasizes how unpredictable weather can be.”
He said the implications of this trend include more snowfall in midwinter, particularly December through February, and less snowpack by April.
“Snowpack relates to accumulated amount plus melt — and extra melt comes into play,” Trenberth said. ”The increases in some storms are probably more than offset by more rain at the start and the end of the season.”
It is getting warmer throughout the year in the state of New Jersey, said David Robinson, a professor in the Department of Geography.
Despite this trend, there does not seem to be a reduction in snowfall, Robinson said. He said New Jersey has been known to have its fair share of heavy snow events in the past decade or two and there should be no fear of a shorter winter season.
“Evidence in recent years includes the major snow of October 29, 2011 or the snowstorm in early November 2012, just 10 days following Sandy,” he said.
New Jersey will continue to see some heavy snowstorms in the future, though the timing of them will vary as well as the frequency per year. Robinson said current 30-degree storms might become merely rainstorms decades later.
A problem with being accurate about winter trends in New Jersey is the freezing point, Robinson said. Just a few degrees above or below can make a huge difference in winter conditions.
He said the Garden State just happens to be where the temperature often straddles the freezing point from late fall to early spring.
Moreover, the region-wide agriculture would have to deal with persistent weather patterns, whether it involved prolonged abnormal heat, cold, drought or precipitation, said Jennifer Francis, a professor in the Institute of Marine and Coastal Sciences.
“Unfortunately, we can’t predict reliably which pattern will occur at any particular location,” she said. “[In] some winters, we could get stuck in a persistent stormy pattern, but depending on the location of the jet stream, that could mean rain or heavy snows.”
Robinson said New Jersey agriculture should not be impacted much if there is less snow. He said less than half of precipitation falls as snow, and there is no need for a long duration snow cover. Snow packs are not necessary to provide water to reservoirs, either.
If there is an abundance of winter precipitation, issues may arise that cannot be foreseen. Robinson said models suggest winter precipitation in this area will not change much. He said at most, there might be only a slight increase.