VERMONT CLIMATE OVERVIEW | Chapter 1
Report Findings: Vermont average temperatures have increased 1.3 degrees since record keeping began in 1960. The last decade was the warmest on record. Additionally, winter severity in Vermont has and will continue to decrease. Warming has been twice as fast in winter than in summer. As a result of warmer winters, rivers and lakes in Vermont have been observed frozen at a rate of 7 less 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. Temperatures in Vermont are expected to continue rising. Vermont’s annual precipitation has increased by 6” per century since 1895. The largest increases have been in the mountainous regions. More winter and spring precipitation is projected for Vermont over this century, initially increasing snowfall but, as temperatures rise, later increasing winter rainfall. Vermont’s natural climate varies across the state and the impacts of anthropogenic climate change will not be consistent across the state or over time.
CLIMATE CHANGE POLICY IN VERMONT | Chapter 2
Report Findings: The exact magnitude of global climate change will depend primarily on potential future amount of global greenhouse gas emissions.
Vermont can play a role in demonstrating systemic change for decreasing green house gas emissions. The Vermont State Government has been taking action towards emissions reduction programs since the beginning of the century. A constituent base that values climate change action across the state generally supports current legislation to advance the state goals of a 50% reduction in greenhouse gas emissions by 2028 and 90% of energy from renewable sources by 2050.
COMMUNITY DEVELOPMENT | Chapter 3
Report Findings: Certain types of extreme weather events have become more intense and frequent in Vermont, including short term dry spells, floods, and high-energy storms. As average annual rainfall has increased in recent decades, average annual flows in Vermont rivers have increased.
Rural and urban communities around Vermont are at risk of these impacts. Many communities have already been highly impacted and are engaged in processes to respond to climate change related transitions through formal planning. Community’s infrastructure systems are highly vulnerable to climate change. This vulnerability is exacerbated by the state’s mountainous, rural geography and small rural communities with limitations existing in transportation routes and communication systems. ENERGY | Chapter 4 Report Findings: Energy demand will rise as temperatures in both summer and winter increase. The temperature rise in summer and the increased use of air conditioning will likely outweigh the reduction in energy demand for heating in the winter. Increased risk of major storm events in Vermont will threaten energy infrastructure. In June and July of 2013 alone, 70,000 separate energy outages occurred in Vermont. In Vermont, forecasts to 2030 anticipate peak energy load increasing .7% annually due to increased demand for air conditioning. Adaptation through the use of renewable, local energy sources will be critically important as extreme weather events increase and threaten fossil fuel based energy supplies. Energy efficiency and conservation are key components of Vermont’s goal of 90% renewable energy sources by 2050. Energy policy attempts to leverage behavior change to accomplish energy efficiency goals.
WATER RESOURCES | Chapter 5
Report Findings: Warmer temperatures are leading to earlier thaw dates on Vermont’s rivers, lakes and ponds and snowpack in the mountains. Average annual stream flows are shifting and overall are expected to continue increasing in coming decades.
High flows are occurring more frequently. Under assumptions of high green-house-gas emissions scenarios, up to an 80% increase in the probability of high stream flows is projected by end of the century. January, March, July, August and October through December stream flows have increased while monthly averages for April and May have decreased. Climate models project more frequent high flow events (and flooding), particularly in the winter months as a greater fraction of winter precipitation will fall as rain or freezing rain rather than snow. While Vermont rivers have sustained higher levels of base flow over recent decades in summer months in contrast to other New England states, climate projections show increased potential for short-term dry spells.
FORESTS | Chapter 6
Report Findings: Increased temperatures will lengthen growing seasons and increase suitable range for certain Vermont tree species like oak, hickory, and red maple, but decrease suitable range for cold-tolerant species like spruce and fir. Changes in precipitation cycles (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.
Certain models project that by the end of the century, the northeast could be dominated by an oak-hickory forest, with spruce-fir forests being virtually non-existent and maple-beech-birch forests being driven north to Maine. Warmer temperatures will result in earlier bud burst and flowering periods for certain species, making them more susceptible to pests and pathogens. Warming temperatures may threaten plant and animal species in our forests by changing growing conditions that are unfavorable or that encourage invasive species. It is important to consider climate refugia where changes will be minimal and species can be preserved.
AGRICULTURE AND FOOD SYSTEMS | Chapter 7
Report Findings: Warmer seasonal temperatures will result in later “first-fall freeze” and earlier “last-spring freeze”. This extended growing season can increase overall crop productivity and create new crop opportunities.
The potential negative effects include increased stress from weeds growth, disease outbreaks, and pest infestations. Higher CO2 in the atmosphere promotes photosynthesis and can potentially fuel the growth of many Vermont plant varietals. For Vermont livestock operations, summer heat stress could lead to slight decreases in livestock productivity. More pronounced climate change impacts come from pasture productivity and other production inputs such as feed costs and energy costs. Variations in seasonal precipitation combined with the increased frequency of high-energy storms could lead to extreme year-to-year weather variations with implications on farm business viability.
RECREATION AND TOURISM | Chapter 8
Report Findings: Within 30-40 years, average winter temperatures are expected to increase to the point that most winter precipitation will fall as rain, which will result in shorter-lasting snowpack and snowfall, reducing the winter tourism and recreation seasons. However, over the next 25 years, snowfall in mountainous areas may increase with increasing winter precipitation (a climate change “sweet spot”), which would have a positive impact on winter-related recreation and tourism industries.
The summer tourism and recreation seasons will lengthen, and increased temperatures combined with higher humidity further south are expected to drive more tourists to Vermont. Increased temperatures will encourage expansion of pest species, reducing the quality of the recreation experience and requiring increased monitoring and treatment. Fall recreational opportunities and tourism will lengthen with the warmer temperatures, creating expanded economic opportunities.
HUMAN HEALTH IMPACTS | Chapter 9
Report Findings: Associated physical impacts of climate change will prove to have a serious impact on the health of Vermont’s citizens including accidents from extreme heat and weather events, increasing rates of certain infectious diseases, respiratory stress, and food security concerns. The risk of injuries, illnesses, and deaths related to extreme heat and weather events may increase as these events become more frequent.
The burden of infectious diseases may increase due to changes in vector and zoonotic biology as well as changes in water and food contamination. Allergy and respiratory symptoms may increase in relation to increasing plant and mold allergens and irritants in air. Nutritious and sufficient food could be threatened related to food production changes in response to climate change. Some of the key drivers of health impacts include: increasingly frequent and intense extreme heat, causing heat-related illnesses and intensifying air pollution; and increasingly frequent extreme precipitation with associated flooding that can lead to injuries and increases in freshwater-borne disease.
TRANSPORTATION | Chapter 10
Report Findings: Flooding poses the greatest risk to transportation infrastructure in Vermont, but more acute erosion, extreme heat events and winter storms will also create damages. Increasing frequency in freeze-thaw events weaken bridges and frost heaves and potholes lead to higher burden in road construction costs annually.
Vermont’s rural nature compounds the complexity of maintaining a strong transportation network. The damages from Tropical Storm Irene’s flooding totaled over $200 million to Vermont’s State Highway system affecting over 500 miles of roads and 200 bridges throughout the state. Increases in precipitation exacerbate risk of fluvial erosion along roadways and washout of overstrained culverts. High soil moisture levels may lead to increased vulnerability of structural foundation for roads, bridges and tunnels. The transportation sector accounts for 44 percent of Vermont’s overall GHG emissions. Vermont’s transportation sector will need to focus on both mitigation of risk and adaptation to climate change impacts.
EDUCATION AND OUTREACH | Chapter 11
Report Findings: Despite many efforts and much progress, there is a long way to go in the use of education and outreach to help Vermonters mitigate and adapt to climate change through changes in their own behavior (energy usage, consumer behavior, etc.).
Over the past 15 years the Vermont State Government, and in particular the current Governor’s Office, has taken a lead role in promoting education and outreach with respect to climate change. Vermont’s institutions of higher education are also very active in conducting research and disseminating knowledge to both the scientific community and the public at large. The study of climate change is only partially, but increasingly, incorporated into K-12 education. Student knowledge of earth science lags behind that of biological and physical science. Combining climate change educational activities with appeals to Vermonters’ values, changes in material incentives through policy reforms, and strengthened social norms could induce more pro-environmental behavior