• NATURAL SELECTIONS:
Winter storms and climate change.
As Roxborough digs out of last week’s 8 inches of slush and ice dumped by winter storm Stella, the staff at the Schuylkill Center has been asking an important question: what is the relationship between this storm and climate change, if any?
After all, we’d just come out of the warmest February in the more than 100 years of Philadelphia record keeping, and four February days peaked above 70 degrees, something that also has historically never happened before. In fact, February set 11,700 local weather records across the country. Our trees had started leafing out already, especially crab apples, in late February, crazy early, and the first recorded toad crossed Port Royal Avenue on March 1, one of the earliest such sightings in our short history of helping Roxborough toads cross the road.
And Washington’s famed cherry blossoms were set to open last week, also among the earliest dates for that ever.
With all of us assuming March would continue this progression, of one of the earliest springs in memory, imagine our surprise when it snowed twice in March, first two weeks ago and then Stella, suddenly two snow days in back-toback weeks.
First, we should not be surprised at a March snowstorm; we’ve had snow even in April before. Second, we can never pin one weather event on climate change — no one event is proof of anything. With weather, one pays attention to long-term trends for discerning patterns.
And the corollary of this is last week’s storm is likewise not proof that climate change is a hoax invented by, well, I’m not sure who. One event neither proves nor disproves anything.
Let’s think this through for a moment. One of the working theories of climate change is that, as the atmosphere warms, more water evaporates into the sky.
Makes sense, yes? Warmer skies hold more water, and the earth’s surface is two-thirds water. More water is evaporating in a warming world, and that water has to fall somewhere, so perhaps climate change means an increase in precipitation — and in winter, precipitation means snow.
Consider this. In Philadelphia, since weather records began in the late 1800s, four of the top 10 storms recorded have fallen in the 2000s, only in the last 17 years. And another was recorded in 1983 (about when the last M*A*S*H episode ran, right?) and a sixth in 1996. I moved to Philadelphia in 1982 to work at the Schuylkill Center, and in my 30-plus years of living in the region, I have seen six of the top 10 winter storms.
Likewise, I’ve seen at least five 100-year rainstorms, storms that statistically should occur only once every 100 years (and one labeled a 500year storm). In 30 years, I should not have seen even one. Yet I’ve seen five 100year rainstorms and six of our largest snowstorms.
In a similar vein, New York City has had seven of its top 10 snowstorms since 1996; Boston six of its top 10 in that same period. Baltimore and D.C. have suffered five of their top 10 in this time period.
So a large winter storm — created by an energetic atmosphere with a lot of water in it — seems increasingly the norm.
Many climate scientists have also noted that climate change increasingly means a “weirding” of our weather — that the erratic climate creates dramatic mood swings in Mother Nature. So a feverishly warm February yields to a snowy early March — and suddenly this week’s temperatures are back in the 50s and will hit high 60s on Saturday.
Out my kitchen window is a forsythia bush that was set to bloom early, and then Stella hit, freezing and killing the about- -to-open flowers. I’m curious if it can rebound, but this may be a spring without forsythia, which will be odd (the plant should be fine next year — this is just a one-year hiccup). While this is mildly annoying for me, for farmers, these late winter storms are horrific. Lots of fruit trees, like New Jersey’s famed peaches, were flowering early, and this storm killed the flowers — which become the fruit. Cranberries and blueberries are likely in trouble, too. So farmers are unnerved by the increasingly erratic weather.
DC’s cherry blossoms may rebound, but one report I heard indicated half of the flowers have been killed. So it will be a substantially different experience this year.
Climate change is a far more serious phenomenon than our politicians in D.C. indicate. If correct — and factual nonpolitical realworld measurable data indicates weather is changing more rapidly than models predicted — crops will fail, cities will be submerged, people will be sicker, storms will become more violent.
So no, Stella alone is not proof of climate change. But so many hard winter storms in just the last 20 years?
Like snow, the data is accumulating to quite some depth.
First, we should not be surprised at a March snowstorm; we’ve had snow even in April before. Second, we can never pin one weather event on climate change— no one event is proof of anything. With weather, one pays attention to long-term trends for discerning patterns.