It may feel like winter today, but just a few days ago, temperatures were at record highs. Last month was one of the top 10 warmest Novembers ever recorded in Boston.
Last month was one of the top 10 warmest Novembers ever recorded in Boston.
The 60-degree days were great for people watching their home heating bill or cutting down Christmas trees in short sleeves, but it doesn't sit well with Newburyport artist Erin Stack.
"It's sort of weird to be sweating in the middle of November," she said. "I think it's pretty palpable climate change. For me, I'm glad it's cool today. It's really caused me a source of anxiety."
Stack is certainly not the only person who connected the warm weather to global warming.
But is there really a scientific connection?
"The best answer is that one warm November doesn't make global warming and one cold November doesn't negate it," said Bill Moomaw, a professor of international environmental policy at Tufts University's Fletcher School. "What it's really about is the pattern over time."
The pattern is that New England is getting warmer. We now typically have 16 fewer days with snow on the ground than we did 30 years ago, according to a study co-written by University of New Hampshire scientists and a nonprofit advocacy group. Lilacs bloom four days earlier. River ice is breaking up an average of 11 days sooner than it did in the 1940s. In Massachusetts and New Hampshire, average temperatures have risen 2 degrees in the last century.
Last month was one of the top 10 warmest Novembers ever recorded in Boston.
The 60-degree days were great for people watching their home heating bill or cutting down Christmas trees in short sleeves, but it doesn't sit well with Newburyport artist Erin Stack.
"It's sort of weird to be sweating in the middle of November," she said. "I think it's pretty palpable climate change. For me, I'm glad it's cool today. It's really caused me a source of anxiety."
Stack is certainly not the only person who connected the warm weather to global warming.
But is there really a scientific connection?
"The best answer is that one warm November doesn't make global warming and one cold November doesn't negate it," said Bill Moomaw, a professor of international environmental policy at Tufts University's Fletcher School. "What it's really about is the pattern over time."
The pattern is that New England is getting warmer. We now typically have 16 fewer days with snow on the ground than we did 30 years ago, according to a study co-written by University of New Hampshire scientists and a nonprofit advocacy group. Lilacs bloom four days earlier. River ice is breaking up an average of 11 days sooner than it did in the 1940s. In Massachusetts and New Hampshire, average temperatures have risen 2 degrees in the last century.
Greenhouse gases are in the news as Massachusetts argues a global warming case before the Supreme Court and Al Gore's global warming documentary "An Inconvenient Truth" comes out on DVD, so it's only natural for one to wonder if greenhouse gases are behind the balmy weather we've experienced.
Bruce Anderson, a professor in the geography and environment department at Boston University, agrees that it's impossible to make a direct connection between last month's weather and global warming, but climate models predict that this is the kind of unseasonable weather global warming creates.
"I guess this would be not a harbinger exactly," Anderson said, "but it certainly is the type of weather phenomenon that we're likely to see in the future."
Meteorologist Walter Drag with the National Weather Service in Taunton, though, is skeptical of such predictions.
"We're certainly in a cycle of warming," Drag said. "What's causing it we're not sure. ... There's enough information out there to say we are in a cycle of warming over the last two to three decades. That doesn't mean it's going to go on forever or that it couldn't abruptly reverse."
An El Nino pattern appears to be developing in the Pacific Ocean, which could mean a slightly warmer winter in New England, but even that is unpredictable, Drag said.
"Right now it's been warm, but as far as we're concerned, it's not going to be a dominant theme throughout the winter," he said.
Paul Kirshen, a Tufts professor who studies the potential impacts of climate change, is already planning for a warmer future, record-setting November or not.
When he put an addition on his house a few years ago, he made the gutters bigger than he had to because heavy rainstorms are predicted to become more frequent, Kirshen said. He made the eaves overhang a little farther for more shade.
"That's cheap," he said. "It's nothing."
Local governments should make the same preparations, he said, because it's much cheaper to do it now than to wait until sea levels are higher and storms are more violent to change existing buildings. For example, he argues that building codes should be adjusted to require new subdivisions to have more water-storage capacity in anticipation of heavier rain.
On a personal level, anything you can do to use less energy will help, Moomaw said. Don't leave your Christmas lights on overnight. Try to drive 30 fewer miles each month. Buy a fuel-efficient car.
Stack, the Newburyport artist, was eager to hear if climate-change experts actually connected the warm weather to global warming. Even though they don't, she said, it doesn't change the fact that people are noticing the changes in the environment little by little and are starting to pay more attention to the environment.
"This is how change will happen," she said.
Did we set a record?
It's funny how we remember unusual weather but quickly forget the ordinary. Last month may have been one of the warmest Novembers on record, but do you remember what the weather was like in October? How about September?
According to National Weather Service data, October weather was typical. The average monthly temperature was 54.3 degrees, which is just one fifth of a degree higher than normal. September was typical, too. The average temperature was 64.6 degrees, which is a tenth of a degree colder than normal.
Average monthly temperature for November in Boston is about 44.9.
Year%Average temp.%Departure from normal%Highest temp.%Lowest temp.
2006%48.7%3.6 degrees warmer%69%32
2005%45.9%1 degree warmer%70%21
2004%44.3%0.6 degrees cooler%66%24
2003%45.9%1 degree warmer%76%27
2002%42.9%2 degrees cooler%70%19
Source: National Weather Service
Why was November so warm?
The warm weather in November was due to the North Atlantic Oscillation, a weather phenomenon that pushes around the jet stream over the Atlantic Ocean. The jet stream is a flow of air in the atmosphere. Storms tend to follow its path, which is why it is also know as the storm track. The North Atlantic Oscillation tends to push the jet stream into a position and hold it there for 10, 20 or 30 days.
Around the beginning of November the North Atlantic Oscillation pushed the jet stream north of us. That held the cold air and storms to the north and bathed the region with warm air from the south. Now that the jet stream has moved back, more seasonal winter weather is on its way.
Source: Bruce Anderson, a professor in the geography and environment department at Boston University
What the experts say
Climate scientists agree, you cannot link any one particular weather event to human-generated global climate change.
Even if the chemistry of the atmosphere hadn't been changed by human activity, you could still have an unusually intense hurricane or a warm November once in a while. How can you prove this event wasn't just part of the natural cycles of weather?
What they can say is that their models predict this type of weather will become more common as climate change intensifies. A warm November may not be proof of global warming, but it is a reminder for some people of what may lie ahead.
We asked climate change scientists what else in their daily lives gives them pause and draws their attention to the warming trend:
"Just the fact that some of my spring plants in my yard are coming up right now in November does disturb me a little bit."
Bill Moomaw, a professor of international environmental policy at Tufts University's Fletcher School. He has also noticed the decline in snowfall has made it a little harder to do winter sports.
"I can't cross-country ski as much as I like in my backyard," said Paul Kirshen, a research professor in the civil and environmental engineering department at Tufts University. "But on the other hand, it's not as uncomfortable running in the winter as it used to be."
"What hit me were the storms we had last spring," said Bruce Anderson, professor in the geography and environment department at Boston University. He got so much rain at his apartment that it saturated the brick in his chimney and water wept out. "It made me realize that these heavy, heavy precipitation events, these heavy rains, are a preview of the type of storms we can expect to have in the future."
