By Michael Caduto
In January of 2023 the World Meteorological Organization analyzed six different sets of weather data from around the world and concluded that 2014 through 2022 were the warmest years ever recorded. The increased heat energy from global warming has transformed Earth’s atmosphere into a meteorological engine that is driving the dramatic rise in both the frequency and severity of storms worldwide.
Among the recent cataclysmic and tragic impacts of this extreme weather is the flooding on a massive scale experienced by Pakistanis in 2022 over a vast land area 3 ½ times the size of Vermont. This antediluvian event threatens the health, safety and survival of more than 15 million people, including 10 million children. Massive international assistance of food and medicine is required to prevent widespread starvation and disease.
Following several years of historically unprecedented draught and fires in California—catalyzed by global warming—the extreme weather pendulum has now swung the other way. According to the Los Angeles Times, recent “megafloods” in early 2023 have killed at least 22 people, knocked out power to 100,000 customers and caused an estimated $1 trillion in damages.
Vermont is situated in the midst of a large region experiencing some of the most extreme temperature increases in North America as a result of the rising emissions of greenhouse gases. According to NOAA (National Oceanic and Atmospheric Administration), temperatures in Vermont have increased 3°F since 1900, with the last 12 years being the warmest on record. Rainfall now averages 6 inches more per year than it did in 1960. Extreme weather events have also increased in recent decades, vacillating between extended draughts and intense record-setting rainfalls, such as 2011s Tropical Storm Irene and the $700 million in damages and tragic impact on the lives of Vermonters. This trend is expected to continue, bringing with it more frequent and severe storms and warmer winters with fewer days of extreme cold. This winter it was late-January before many parts of Vermont experienced the first significant accumulation of snow.
How are these meteorological shifts affecting Vermont’s iconic rural activities and drivers of our domestic and tourism-based economies? Consider Vermont’s $50 million plus maple sugaring industry, by which Vermont produces a nation-leading volume of some 2.5 million gallons per year (2022). While modern technologies—such as plastic tubing, vacuum systems and reverse osmosis—have enabled maple sugar-makers to increase the volume of syrup produced, the sap-to-syrup ratio has declined precipitously. Research conducted at farms that have kept detailed records of their maple sugaring operations in the same sugar bushes for a century or more has revealed a dramatic drop in the sugar content of sap by nearly 30 percent since the 1970s—during the exact same span of time when atmospheric temperatures began to rise exponentially. In the 1970’s it took 25 to 30 gallons of raw sap to make 1 gallon of syrup. Nowadays, however, 45 to 50 gallons or more of sap must be processed in order to produce the same yield. This is due to stresses placed on sugar maples by conditions they are experiencing as a result of global warming and other forms of atmospheric pollution. For example, long-term research at the Hubbard Brook Experimental Forest has revealed that the growth of sugar maples decreases by 40% if their roots are exposed to severe cold when there is no snow pack—a drop in growth that continues for several years.
Whither Vermont’s fall foliage season, which brings in much of the state’s autumn tourist revenue of $460 million? Says Dr. Barrett Rock—professor emeritus of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire, “Serious change in our climate became really noticeable in the mid-1970s, as if a switch had been thrown at that time, including increased temperatures and reduced air quality. Significant changes in forest health also began in the 1970s and all data indicates that it is now occurring at an increasingly rapid rate. This corresponds well with what the climate change models predicted.”
The first hard frosts, which bring out the most vibrant leaf colors, used to occur around the third week in September. But in recent years, these frosts have arrived later. As Rock has observed, “There was a time when Columbus Day was widely recognized for planning a visit to New England for spectacular colors. Now the foliar change may not have even begun by early October, and frost sometimes comes as late as early November.”
Parallel trends have been reported by researchers at the University of Vermont as well as at the Harvard Forest Research Station in Petersham, Massachusetts. Cornell plant biologists found that stress placed on trees due to climate change and other forms of air pollution, such as high ozone levels and acid rain, is causing many leaves to brown off and die without much color change. Leaves are also more prone to being invaded by fungi and bacteria seeking sugar to feed on.
Drought, late-season warmth, and the cloudier days associated with climate change all have the effect of muting autumn leaf colors, which now often progress, as Rock has observed, “from green to pale yellow, followed by leaf fall. Stressed trees have difficulty making anti-fungal compounds, which makes it hard for them to create the beautiful bright colors.”
Vermont’s $1.6 billion ski industry is also feeling the heat, marked recently by surreal warm spells that keep melting and re-melting the snowpack. According to the findings of the Vermont Climate Assessment, depending on the level of carbon emissions in coming years Vermont’s ski season will be foreshortened 2-4 weeks by 2080. With snowmaking machines, most operations manage to generate sufficient snow cover on ski trails despite the paucity of natural snow. Still, the operational changes imposed by climate change—such as running snowmaking machines more frequently—reduce profit margins and increase the impact on aquatic environments due to the need to draw more water to make snow.
With change being the only constant on the horizon in the coming decades, the future success of Vermont’s traditional sources of seasonal revenue will depend on the state’s ability to adopt and prove resilient in the face of an increasingly warmer climate.
Photo: Michael J. Caduto