Robinson discusses climate change with Garden State’s organic growers
New Jersey State Climatologist and Rutgers Professor Dr. David Robinson kicked off a series of virtual talks on the second day of the Northeast Organic Farmers’ Association annual conference on Jan. 31.
The Hillsborough-based Robinson is also an earth scientist and geographer, and he is frequently consulted by news media for comments on weather events in the Garden State.
He was appointed state climatologist three decades ago by the then-dean of the Rutgers Agricultural Experiment Station. Robinson studies climate change, drought, flooding, issues related to agriculture, transportation, public safety and commerce and has served on a number of national committees.
The Rutgers Ag Experiment Station runs a network of 65 weather stations from High Point Monument in Sussex County down to West Cape May in Cape May County.
Weather stations are scattered in rural areas, including Rutgers-owned research farms as well as urban and suburban areas.
“We have about 300 weather observers and about 100 of them report in every day,” he said.
“New Jersey has a wide-ranging, wonderful climate system,” Robinson said.
“We have the benefit of being in the middle latitudes, so we have all four seasons to experience. We can get all sorts of extremes.”
These extremes include weather events like flash floods, minor tornadoes and brush fires in the Pinelands region and elsewhere around the state.
“We can go from plenty of moisture to a flash drought very quickly. It can turn on a dime. You can get a hot dry spell of four to six weeks in the middle of the summer,” he said, “and we cannot forget the worst of the worst which has to do with our maritime location.”
He referred farmers to a website Robinson and his team keeps updated, www.njclimate.org.
Recapping weather records from 2020, he said the first half was on the dry side, and then along came Tropical Storm Fay on July 10 and then a much wetter second half of the year. 2020 was also marked by the hottest July in 126 years of record keeping.
“The fact is, in the last century or so, New Jersey has gotten warmer; if you look at [records from] the last forty or so years, it’s warming even faster,” he said. 2020 was not the warmest year on record, that distinction goes to 2012.
“New Jersey is getting warmer and with that we’ve had a longer growing season and frost-free season,” he said. The growing season is now over a week longer in the northeast than compared with the first 60 years of the 20th century.
Robinson also pointed out how great the variation can be from season to season, and said a cool year now is equivalent to a warm year of 100 years ago.
By way of variability, he pointed out last year, the last freeze at Atlantic City marina was March 1, “while the last freeze at our station up in Walpack in Sussex County, an extreme northern point in the state, was June 1. That’s a three month difference to the start of the growing season.”
By contrast, the first fall freeze in Walpack was Sept. 19 to end the growing season.
It was around Nov. 15 at the Atlantic City marina.
“The growing season in coastal New Jersey is five months longer than in the hills and valleys of northwestern New Jersey,” he said, “but you people know all this, the people who know our weather the best are farmers, mariners and aviators.”
Other trends from 126 years of weather record keeping that he and others at Rutgers have identified include 6 to 7 percent more precipitation. The two wettest years were 2018 and 2011, and he noted 2011 was punctuated by Tropical Storm Irene at the end of August that year.
What do all these weather stats mean for the state’s growers?
“You have to be prepared for a wider range of possibilities with your annual precipitation than you did 100 years ago,” Robinson said. “Five of the seven largest floods of the last century have occurred since 1999.”
As a climatologist one has to be a lot more patient than a meteorologist, he said, but climate change is real and it’s happening in the Garden State.
“That’s the what. The why is humans are responsible for climate change. When you look at the records you can’t see a signal until the 1970’s and early 1980’s, and until that time you simply can’t explain the change that has occurred by saying it’s natural variability.
“This is based on many models and many observations” from around the world, he said.
While far from a perfect analogy, “when you’re cold you put a blanket on your bed, eventually the heat will make its way out. What we’ve been doing with these greenhouse gases amounts to an extra blanket on your bed. We have more dust, soot, solid particles in the atmosphere and they absorb solar radiation, heating the atmosphere and adding to warming.
“For the Mid-Atlantic region, it looks like steadier increases in precipitation, particularly in winter, maybe not so in summer, and hotter dryer summers can be a worry if you don’t have the water resources or irrigation,” Robinson said.
More moisture in the atmosphere means we can get an awful lot of snow, so when a trigger comes along, it’s kind of all or nothing, he said.
“When it gets cold enough to sustain snow, you can get more snow, so we’re going to be seeing more extremes in flooding, drought, heat waves and such, in future years.”