WHAT'S HAPPENING TO WINTER IN THE NORTH

National Wildlife Federation - Global warming is having a seemingly peculiar effect on winter weather in the northern United States. Winter is becoming milder and shorter on average; spring arrives 10 to 14 days earlier than it did just 20 years ago. But most snow belt areas are still experiencing extremely heavy snowstorms. Some places are even expected to have more heavy snowfall events as storm tracks shift northward and as reduced ice cover on the Great Lakes increases lake-effect snowfalls.

Even as global warming slowly changes the character of winter, we will still experience significant year-to-year variability in snowfall and temperature because many different factors are at play. Milder winters disrupt ecosystems in some surprising ways. Bitter cold temperatures naturally limit the spread of pests, diseases, and invasive species.

The absence of extreme winter cold across the mountainous West has enabled an explosion of mountain pine beetles and caused a massive die-off of pine forests. Some important plants-for example, walnuts, peaches, and cherries- require a certain exposure to cold in order to flourish. Plants and animals also can be caught unawares when milder conditions are punctuated by severe winter weather. Across the Great Plains and Southeast United States, a cold snap in early April 2007 caused more than $2 billion in crop losses after an unusually warm March led to premature crop growth.

Large economic uncertainty and potential losses are in store for many communities, especially in regions where winter recreation provides significant tourism revenue. Many ski resorts will see shorter, rainier seasons, which will negatively impact the $66 billion dollar industry and the tens of millions of Americans who ski each year. Lakes across the Midwest are freezing later and have thinner ice, often leading to ice conditions too dangerous for safe ice fishing. Roadway snow removal and wintertime flood management also will be complicated by more erratic winter weather; government agencies may have to account for much more year-to-year variability.

Sally Stockwell, Maine Audubon - Warmer winters mean we could see populations of moose, lynx, and pine marten all decline, as these species are adapted to cold temperatures and heavy snowfall. U Maine scientists also predict populations of our state bird, the black-capped chickadee, will become less common or even disappear from much of the state except western and northern Maine. . .

In northwestern Minnesota the moose population has dropped precipitously in the past two decades from 4,000 to 100 moose. After 7 years of study, biologists from the Minnesota Department of Natural Resources suspect the ultimate cause of the decline is climate change.

Moose become stressed from the hot weather and die from diseases like brainworm or from heavy. Warmer winters increased deer populations, which carry a brain worm that is harmless to whitetails but fatal to moose. Warmer weather also increases winter ticks that bother moose so much they rub off both the ticks and their thick protective hair, leaving them vulnerable to death from exposure.

Warmer weather along with healthy populations of deer in southern Maine is already leading to a rapid spread of the deer tick and Lyme’s disease throughout Maine.

More southern species like the Carolina wren and opossum are moving into Maine and surviving our winters where they never could before. Other species that are more common south of the border will likely expand north into Maine.


Heavy rainfall on top of snow will lead to increased problems with ice jams and flooding, and washouts of culverts that can’t handle the increased flow, interfering with travel of fish and other aquatic animals up and downstream. This could be especially problematic for our prized wild native brook trout and salmon.