Ixodes scapularis


As Vermont’s climate gets warmer and wetter from climate change we will need to plan for potential health impacts that these changes will have on Vermonters. There will likely be more dangerously hot summer days, more pollen in the air, and more days of the year when ticks that carry Lyme disease can be out and biting.   

Across the United States and around the globe, serious health issues are already on the rise as a result of changes in climate. This is one more important reason to work together to reduce greenhouse gas emissions.

How Hot is Too Hot?

We already know that Vermonters are at greater risk of serious heat-related health impacts and even death when the temperature reaches the mid-to-upper 80s.  During the decade between 2004 and 2013, Vermonters were eight times more likely to visit emergency rooms for heat complaints on days when the temperature reached 87°F or greater, and on these very hot days there was an increase of one additional death per day among those over 65 years old.  

Although 87°F may not seem very hot, Vermonters may be particularly at risk because we don’t experience hot weather very frequently. Many Vermont homes do not have air conditioning, and many Vermonters work and play hard outside on summer days that are usually pretty mild.  In addition, Vermont has a large population of older adults, who tend to be at higher risk for heat illnesses. 

In the future, we can expect more days each year when temperatures reach unhealthy levels.  On average over the past 30 years, there have been about six days per year when temperatures reached or exceeded 87°F.  Projections by climate scientists show that we can expect an average of 15 to 20 of these hot days per year by 2050, and 20 to 34 by the end of the century.

Tick and Mosquito Borne Diseases on the Rise

Link to Vermont Department of Health Tick Tracker
The VT Department of Health Tick Tracker
Reported cases of Lyme disease and anaplasmosis, both transmitted by blacklegged  ticks (commonly called "deer ticks"), have increased in Vermont in recent years. Over 380 confirmed cases of Lyme disease have been reported each year since 2011, up from 60 or fewer before 2006.  Vermont had the highest incidence rate of Lyme disease in the nation in 2015. Confirmed and probable cases of anaplasmosis have also increased from 3 in 2010 to 139 in 2015. Diseases transmitted by mosquitos, such as eastern equine encephalitis and West Nile virus, have also been reported in Vermont in recent years

Warming conditions are one of several factors that have contributed to an increased distribution and abundance of black-legged ticks in northern states that can transmit pathogens causing Lyme disease, anaplasmosis, and other diseases. Climate change is expected to further expand the black-legged tick northward range and lengthen the tick activity season, likely leading to an increased risk of tick-borne diseases in Vermont in the future. Warmer and wetter conditions will likely increase mosquito abundance and activity, and may facilitate the introduction of mosquitos that can transmit pathogens not currently found in Vermont.

More Pollen Means More Allergies

Climate change is lengthening the growing season in Vermont, a change which may also extend the length of the pollen allergy season.  Recent research from the Midwest reported that the ragweed pollen season has increased by over two weeks since 1995 in northern states.  The longer growing season, combined with increased plant growth due to higher levels of carbon dioxide in the air, is likely to increase the allergenic pollen in the air we breathe.  Further increases in allergy triggers could result in widespread respiratory impacts to Vermonters.  

The prevalence of asthma in Vermont adults increased by about 50% between 2000 and 2010.  Adult asthma prevalence in Vermont has been significantly higher than the national rate since 2007, and was the 5th highest in the U.S. in 2014.  About 67,000 Vermonters report having asthma, including about 13,000 children. Further increases in allergy triggers could have widespread respiratory impacts to Vermonters.

 Learn More

These are just a few of the current and future health concerns affected by our changing climate.  Learn about others -- from safety risks from flooding to exposure to cyanobacteria (blue-green algae) --  at the Health Department’s Climate & Health website

The Health Department’s website also has much more information about hot weather, tick and mosquito borne diseases, and drinking water protection.  The Health Department also has a tick tracker where Vermonters can report on tick encounters, providing the Department and the public with valuable information about locations and types of ticks found in Vermont.


Water Quality

Farms & Forests

Tourism & Recreation

Link to Plants and Animals