Sub-freezing temperatures stray from global warming trends

Though this winter's snow and sub-zero temperatures seem to be much worse than the normal Boston winter, until a decade ago, frigid air and icy winds were the norm in the Northeast during this time of year.

Over recent years, winters may have become milder because of global warning, but this year, the trend was disrupted by weather from Russia. According to a report by the National Oceanic and Atmospheric Administration, a sagging jet stream from Siberia allowed immense amounts of cold air to sink farther south into the US and may have caused the sub-freezing temperatures in the New England area and much of the Southeastern states

For about the past 15 years, winter weather has become progressively warmer with less snowfall, according to William Moomaw, a professor of international environmental policy at the Fletcher School of Law and Diplomacy. Current conditions are normal when looking at them in a historical context, he said. "The last ten years have been the warmest on record, both nationally and globally," he said.

The gradual shift has made many Boston-area residents both unaccustomed to and unprepared for the low temperatures. Students who are feeling the icy chill have begun wearing their long underwear, thick jackets, and wool socks _ clothing they didn't need in previous years.

"It's definitely been a much colder January than it had been in previous years," junior Michael Schoenfeld said. "I can't go outside as much and it takes 20 minutes to warm up my car."

Bitter cold gripped the eastern two-thirds of the country Friday, choking northern harbors with ice, shutting down schools and setting more record low temperatures.

The increasingly icy waters shut down some ferries to Boston and New York, forcing commuters into trains and buses.

The Coast Guard was running icebreaking ships through Massachusetts waters to make way for commercial ships. The Northeast gets the bulk of its home heating oil by water.

Further south, residents of North Carolina's Outer Banks were digging out of up to a foot of snow on Friday. But citrus growers in Florida breathed a bit easier because overnight temperatures stayed a shade above the threshold where serious crop damage can appear.

Across the South, temperatures fell to the teens and single digits, with an unfamiliar dip below the freezing mark as far south as interior South Florida.

Record lows for the date included 16 degrees in North Myrtle Beach, SC, well below the 26 degree mark set in 1991.

But this year's temperature drop not expected to disrupt the process of gradual warming in future years. According to Paul Kirshen, a civil and environmental engineering professor in the School of Engineering who has studied global warming and its effects on the Boston area, "We are going to see more periods of unstable weather in the future. We can no longer expect the same climate."

In addition to the effects on weather patterns, many other effects of global warming are noticeable. Sea levels are rising, heat stress deaths occur more often in warm months than it did in the past, and the energy demand throughout the Boston area fluctuates greatly.

If the weather patterns continue on their warmer trend, however, students can look forward to less arctic conditions in the near future.

The Associated Press contributed to this article.