If you’re thinking it’s been unusually warm for, oh, the past 15 months or so, you’d be exactly right.
Since reporting for the Herald on March 2 that Bellingham International Airport recorded its warmest February ever, the months of March, April and May have also been above normal. With May 2015 in the books, that makes 15 consecutive months in which the overall average temperature for the month was warmer than normal.
Last year, it turned out, was tied for the warmest year on record in Bellingham since records were first kept, in 1949.
March was exceptionally warm, at 4.5 degrees above normal. The average temp was 56.7, compared to a normal average of 52.2. Normal is defined as the average from 1981 to 2010. April was just a tad warmer than normal, at plus 0.7 degrees. May was appreciably warmer than average, at plus 3.6.
Rainfall from March through May has been below normal, especially the past two months. For the three months total, rainfall was at 79 percent of normal. The brown grass along your city sidewalk or in your rural field might be telling the tale of the past two months: April and May have been especially dry, at 37 percent of normal (1.9 inches of rain out of an expected 5.17 inches).
What is all this weather talk doing in a politics blog? Even the weather — more accurately, the climate — hasn’t escaped the clutches of politics in recent years. With 15 consecutive months of warmer-than-average weather, and a snow-free Ski to Sea that caused race organizers to cancel the two skiing legs, one might be apt to point to human-caused atmospheric warming as the cause.
Kayaktivists protesting Arctic drilling in Bellingham during Ski to Sea weekend bore signs that made the no snow on Baker-fossil fuel burning-global warming connection. A protest organizer referred to the connection in an interview with the Politics Blog.
But in climate, one year does not a trend make. While the winter of 2014-15 did set a low snowpack record in many parts of Washington state, and the cause was warm temperatures rather than a lack of precipitation, global warming shouldn’t be seen as the culprit, said Cliff Mass, professor of atmospheric sciences at the University of Washington. (Disclaimer: I took classes taught by Mass while I was a Ph.D. candidate in atmospheric sciences in the 1990s.)
Some will be quick to blame global warming from increasing greenhouse gases, but that is an unlikely explanation of a sudden, one-off year like this. Greenhouse gas induced changes would be expected to develop more gradually.
Random, natural variability is more likely the cause.
Of course, some will have other explanations: aliens, secret government weather control projects gone wrong and other ideas we won't get into.
There is simply no analog for last winter and this spring in the Northwest. It stands by itself. And that is why folks (and the media) have to be very, very careful in assuming what the impacts of this weird weather will be.
Mass, incidentally, is a sharp critic of the media, activists and some scientists for overstating the threat of global warming, particularly when it comes to unfounded attempts to link this very real climate phenomenon to an individual weather system. In some cases, Mass says, the exaggeration of the effects of climate change is for political purposes. (Mass thinks Bill McKibben of 350.org is “ perhaps the worst offender” when it comes to linking an individual extreme storm or heatwave to global warming.)
As for the media, Mass says they too often repeat what they are told and don’t check the facts:
The media has to do more homework on the claims of GW/extreme weather connections. All too often they simply quote and replay the baseless claims of advocacy groups, or juxtapose stories on extreme weather events and the potential for extremes under global warming...leaving their readers to reach their own, and often incorrect, conclusions.
Mass is not to be confused with a climate change denier:
I believe the science is fairly clear...the impacts of global warming due to human-enhanced greenhouse gases will be be very significant, that the effects will increase gradually at first, but then accelerate later in the century. There will be substantial impacts on extremes, but the magnitudes and spatial distributions will be complex, and we don't necessarily have a good handle on it at present.