North America produces the world’s maple syrup. What happens when it gets too hot?
Each year in North America, usually beginning sometime in mid-February, winter begins to unfurl its grip and allow spring to breathe itself into the gaps. In the maple syrup-producing pockets of the continent, sunrise moves the thermostat above freezing and sunset swings the pendulum the other way towards frozen nights. Those days are known as sugaring days—the period of four to six weeks when producers gather sap and turn it into the maple syrup that will top our pancakes, infuse our bacon, and sweeten our teas.
In recent years, maple products have undergone a mini-boom, due to our desire for alternatives to high fructose corn syrup; marketing creativity (instead of coconut water, how about some nice maple "water"); and an expanding Asian market. At the same time, however, sugaring days, and the syrup they produce, have grown more volatile due to weather variations linked to climate change.
Freakishly warm winters like this one—in March, NOAA announced that this winter was the warmest on record for the continental United States since record keeping began in in 1901—make it harder on the northeast's maple syrup producers, or sugar makers, are they're known colloquially. It's a reference to the past when maple sap was boiled all the way down to sugar instead of syrup.
"Most sugar makers are genuinely concerned," said George Cook, a maple and farm safety specialist at the University of Vermont Farm Extension. Cook works with sugar makers in Vermont, the state that produces the most maple syrup in the United States, to bring science-based practices to improve their production. "They're obviously looking at what's happening globally and recognizing that if the trend of the northern part of North American continues so that it's getting warmer, the range of the land that is best for the growth of sugar maple trees is going to move north."
"If you don't have those freezing nights and thawing days for a period of for a period of four to six weeks or so the sap is not going to run," he said. "And if you don't get the weather you don't get the sap. We're extremely dependent on the right weather."
"As strange as this winter has been, so has the sugaring season."
Right now, the United States and Canada have the monopoly on global maple syrup production because they're the only place with a climate suitable to wide scale cultivation. The issue isn't simply growing sugar maples—you can find them growing as far south as Tennessee—but getting the sap to run.
"There are some boundaries to the zone of maple syrup production," said Daniel Houle. Houle is a researcher for the ministry of forest wildlife and park in Quebec, and coordinator for the forest resources program in Ouranos a consortium of regional adaptation to climate change. "Up north the climate is too cold for the maple trees to live, and in the south the trees may grow well but you don't have the weather that would allow that you to collect the sap."
This is why the footprint for maple syrup production—as far south as Pennsylvania, north through the Eastern Canadian provinces, and west to about Michigan—is smaller than the footprint for maple trees. And, it's a footprint that's about to get smaller, Houle told Motherboard. "Places like Pennsylvania won't be suitable for maple syrup," he said.
In other places, like the southern part of Québec, the sap will still flow, but the season will likely be shorter, and the frequencies where the weather is less suitable more likely. Overall, Houle's research has found that due to climate change, maple syrup production could see a 15 percent decrease by 2050 and a 22 percent decrease by 2090.
Cook says it's too early in the season to know how producers fared this year. Producers further north and at higher elevations still have sap running, and the official numbers aren't in yet. Plus, it's been an odd season. Some producers found themselves putting in taps as early as December. The sap started to run towards the end of January, such an early start that it smashed tapping records that had endured for more than a century. "As strange as this winter has been, so has the sugaring season," he said.
The product itself has been different as well. Lighter syrups, the kind favored on pancakes and in drinks, are usually produced earlier in the season. Darker syrups, with a stronger maple flavor typically used in baking, are typically produced later in the season. This year's weather has moved the needle toward the darker syrups.
"While some folks have been able to make a nice light product," said Cook, "others have been plagued by a darker-than-average syrup because of the warm weather."
If it's getting too warm in the south, why not just move production further north? "The potential for moving north exists," said Houle, "but there are barriers. You already have another forest there. And the climate is warming much faster 10 to 20 times faster than a tree can migrate."
Producers can also tap trees earlier in the season, said Houle, but tapping them too early could invite bacteria or reduce the yield. "You have to do a kind of compromise," he said.
Maple syrup producers are lucky that compromise is possible at all, however.
"Crops along the tropical belts like cocoa and coffee depend on even temperatures throughout the year," said Kristy Lewis, year climate security science manager at the UK's Met Office.
Those crops can't move to higher or lower latitudes because that introduces seasonality, and they need consistent temperatures. They can only move higher up the mountain until there's no more mountain to move to. "... It will be difficult to know where else you can grow them in the world if you can't grow them in the tropics," she said.
We often think about climate change in terms of what it will do to the weather. If we think about its relationship to food at all, it's in terms of quantity—will we have enough. Increasingly, the questions we should be asking ourselves is not just will we be able to eat, but what will we be able to eat.