Vermont’s maple syrup threatened by climate change

First US state-level climate assessment says maple syrup production will decline as weather warms

Pic: Sterling College/Flickr

Pic: Sterling College/Flickr

By Gerard Wynn

Hotter summers and heavier rainfall in Vermont will threaten the maple syrup industry, but also see some crop benefits, the first US state-level assessment of climate change impacts found this week.

The climate assessment aimed to bring home to Americans the local and personal risks of failing to curb carbon emissions.

The University of Vermont led the study, which partnered with federal and state agencies such as the National Oceanic and Atmospheric Administration and the Vermont Agency of Natural Resources.

It was based on the recent US “National Climate Assessment”, the third and most recent in a series published by the United States every four years and mandated by the US government in 1990.

The national assessment last month said that climate change was “moving into the present”, having widespread, visible impacts on the US people and economy, a view the Vermont report echoed.

“Climate change is no longer a thing of the future; it is affecting Vermont today,” the state assessment said.

“The Vermont Climate Assessment (VCA) is the first state-scale climate assessment in the country and speaks directly to the impacts of climate change as they pertain to our rural towns, cities and communities, including impacts on Vermont tourism and recreation, agriculture, natural resources and energy.”

“Wetter winters and extended dry spells in summers will place more stress on important tree species such as sugar maple and red spruce, which have already experienced periods of decline in Vermont.”

“Of particular significance are adverse effects to agricultural production, including dairy, fruit and maple syrup, more frequent flooding and heavy downpours, and negative influences on winter recreation industries due to reductions in snow cover.”


Climate change is a polarising issue in the US Congress, with the vast balance of support for climate action from Democrats.

It was unclear to what extent the Vermont Climate Assessment was driven by local congressmen, including two senators, a democrat (Patrick Leahy) and independent (Bernie Sanders), and democrat member of the US House of Representatives, Peter Welch.

US President Barack Obama failed to pass a draft climate bill in his first term, a failure that analysts have attributed to the Republican Tea Party’s success in mobilising grassroots opposition. A focus on local, state-level climate risks might counter such opposition.

It was also unclear to what extent other US states may follow the Vermont initiative.

Vermont is the sixth smallest US state by area and the second smallest by population.

Its climate report highlighted increasing local climate impacts, including more frequent and intense downpours, a longer frost-free growing season and higher night-time temperatures.

“The state’s average temperature has increased by 1.3F since 1960; the most recent decade was Vermont’s hottest on record. Rainfall records show that heavy rainfall events are becoming more common and pose threats of flooding.”

“As a result of warmer winters, the time that Vermont’s rivers and lakes are frozen each winter is decreasing by 7 days per decade. Spring has started 2 to 3 days earlier per decade which has increased the growing season by 3.7 days per decade. Due to warmer temperatures and longer growing seasons, Vermont has already transitioned from hardiness zone 4 to zone 5 from 1990 to 2006.”

Regarding future impacts, the report saw an average temperature rise of another 3F warming by 2050 under a low emissions scenario, higher than global average warming recently projected by the Intergovernmental Panel on Climate Change.

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