"Warm Winters Upset Rhythms of Maple Sugar"

In the New York Times

...Dr. Perkins and Tom Vogelmann, chairman of the plant biology department at the University of Vermont, said that while new sap-tapping technology is helping sugar makers keep up syrup production, for now, at some point the season will become so short that large syrup producers will no longer get enough sap to make it worthwhile.

“It’s within, well, probably my lifetime that you’ll see this happen,” Professor Vogelmann said. “How can you have the state of Vermont and not have maple syrup?”...

“In the ’50s and ’60s, 80 percent of world’s maple syrup came from the U.S., and 20 percent came from Canada,” said Barrett N. Rock, a professor of natural resources at the University of New Hampshire. “Today it’s exactly the opposite. The climate that we used to have here in New England has moved north to the point where it’s now in Quebec.”

...Still, he said, “I think what we’re experiencing is a tragic, disastrous change.” He added that he tapped too late last year and made only 1,800 gallons of syrup, instead of his usual 2,500. This year, he said, “in the first week of January, heaven sakes, it was 60 degrees in Vermont.”