Starting in September the whispers of “I hear it’s going to be a bad winter” begin. It’s the most wonderful – or awful – time of year in the Northeast, depending on who you ask and what month you ask them. Snow, ice and the occasional blizzard fill the months between colorful leaves and blooming flowers. Some people embrace this weather, practicing outdoor activities and skiing, while others remain tucked away until the snow melts. Nowadays, it’s hard to pinpoint how early, or late that may be, even though we try! (Click here to read about ice out contests where people guess when ice out is going to be, and if this tells us anything about changing ice out patterns.)
Winter weather in the Northeast becomes wackier and more unpredictable every year. As many of us witnessed recently, a two-day blizzard with freezing temperatures can be followed by a 45-degree day. These kinds of swings can frustrate and confuse people, but what does this mean for the environment and how does it relate to overall patterns of climate change? Pinpointing the relationship between long-term climate change and short-term weather events can not only offer an explanation to our confusion it can potentially establish preventative actions.
In 2010 the U.S. Geological Survey (USGS) focused on winter climate studies in New England, gaining substantial evidence of hydrologic changes during the last 100 years, including trends toward earlier snowmelt runoff, a lower occurrence of river ice, and decreasing accumulation of snow on mountain regions.
Scientists have determined during the past 50 years, there has been widespread warming of global temperature, ranging from 2-degrees C (F) in some areas, to 5.50 degrees C (F) in others. According to the EPA, since 1970, the average annual temperature rose by 2°F and the average winter temperature increased by 4°F in the Northeast. One of the key effects of warming temperatures is increased snowmelt runoff. Forested habitats near rivers and streams, such as the Connecticut River Watershed, are particularly affected. In these ecosystems, snow plays an important role in temperature regulation, while also converting atmospheric energy into heat. Snow cover manages soil warming until snow melts, establishing a temperature range for biological activity. It serves as an insulator for soil, and reduces the extreme effects vegetation face from low temperatures. Snow coverage protects vegetation from drying out in the winter and from erosion of tissues by ice crystals.
A 2006 study by the USGS found that the total number of days of ice in 16 New England rivers each year had declined significantly in recent decades.
Snowmelt and precipitation events have a major influence on the hydrology (properties and movement of water) and chemistry of surface waters. On average, snowmelt contributions to hydrology are slower, compared to light-moderate rainfall, but this increases as temperatures increase. Flooding can occur whenever the rate of water input exceeds the ability of the soil to absorb it or when the amount of water exceeds natural storage capacities in soil, rivers, lakes and reservoirs. The likelihood of snowmelt-related floods increases each year, and studies have been, and continue to be done in areas such as Appalachia (by the Northeast Regional Climate Center) to measure the risk.
Early snowmelt can also lead to reduced summer stream flow while affecting groundwater supplies, particularly recharge zones. Groundwater is crucial to our water supply. Approximately 32 percent of public water suppliers draw water from groundwater sources in Vermont, New Hampshire, and Maine, and approximately 40 percent of the population derives its drinking water from private wells.
Fish and wildlife face threats from warming temperatures and increased snowmelt as well. Salmon, for example, spawn in colder waters during the winter season. These changes can shift the salmon’s migration and spawning patterns, more likely negatively than positively.
These warming temperatures are also melting sea ice and glaciers in arctic regions, threatening the livelihood of polar bears, ranging from reduced access to food, increased cannibalism and higher drowning rates.
The relationship between the Canada Lynx, a listed species, and the snowshoe hare is also being affected by global warming. Lynx depend on hare as their main pray, but as temperatures warm, and snow melts earlier, the ecology of snow is changing. Some lynx are adapted to crusty snow, giving them an advantage. Fluffy snow gives hares an advantage. As temperatures rise, fluffy snow is becoming crusty in some areas, throwing off the balance of this lynx-hare relationship, and ultimately having a negative effect on both animals.
A few degrees and a week or two not only have a cascading impact on our lives, but the ecosystems that surround us. Changes in weather patterns may interrupt our daily lives, but changes in climate are lasting. A disruption in these natural cycles may seem “wacky” to us, but potential for severe, altering changes in the water systems, wildlife, and environment we depend on are at risk.
On a side note, this wraps up my last blog post for my time as the Communications Intern for the Science Applications Department here at Region 5. I’d like to thank the USFWS for a great internship, and all of the followers for taking the time to read my blogs. I not only enjoyed writing these blogs about my interests and passions, but learned a great deal through my research on these topics. I hope you all took away something, whether it be an interesting fact, an inspiration to take part in a clean up like Source for Sea, or a newfound interest of environmental issues!