Wednesday, May 14, 2008

Turtles and Other Signs of Spring

Skunk cabbage beginning to leaf out -- a sure sign of spring.
While out for my morning walk one day a few weeks ago, I stepped into the path of a tiny turtle, a delicate creature, about the size of my middle finger. Attempting to cross the street with a characteristic slowness, she was about two feet from her goal. Nearby was one of her siblings, unmoving -- flattened no doubt under the tires of a passing car. Knowing that a similar fate was more than likely for my little friend, I picked her up - gingerly, as she could be a snapper -- and set her in the grass at the side of the road.

Spring is turtle time - when the momma comes out of hibernation to mate and eventually find her way to a sunny spot in sandy soil to nest. Typically the babies hatch in late summer - as long as a skunk, raccoon, or other predator doesn't find them first. It takes 4-8 years for a turtle to mature to reproductive age, so my little friend was much too small to be a parent. Could last winter's unusually mild and dry conditions have altered the habits of our local turtles?

The stream in my back yard is flowing again, as it does every spring. But this year the amount of water passing by is so slight that in order to see it, I have to perch at the edge of the stream and watch carefully for movement. We had our garden tilled last week and the soil was fluffy and soft - hardly a trace of moisture within. I wonder how the dry winter and spring will affect the growing season.

I never gave much thought to the problem of global warming. After all, it's not supposed to make a major impact for a few thousand years at least. But it's interesting to see very concrete changes that can be attributed to the earth's rising temperature.

In the last hundred or so years, the temperature on the planet has risen about one degree Fahrenheit. That doesn't seem like a big deal - until you consider how it plays out. For example, researchers in Germany studying the budding, leaf-out, and flowering of trees have determined in the past thirty years, botanical spring is now beginning an average of six days earlier than it did in the past. And autumn is coming about 5 days later than before. Here in New England, it's hard to find someone to complain about that -a week and a half has been added to our growing season. But surely there are more serious consequences.

Experts tend to agree that the rising temperature on the planet can in some way be attributed to the burning of fossil fuels such as coal and oil, or rather the emissions this creates - that is, heat-trapping gases such as carbon dioxide. If we continue to produce such gases at the present rate, the global temperature is predicted to rise another two to six degrees by century's end. Again - not such a big deal if it means that spring will come even earlier.

But consider this: since the last ice age, about 20,000 years ago, guess how many degrees the earth has warmed . . . How much cooler was it on our planet back when glaciers were the predominant feature of the landscape? You'd think it would be a lot, but no. Since the last ice age, planet earth has only gotten between five and nine degrees warmer.

So in two hundred years, we might witness changes that before took - by modest estimate - ten thousand years? What does that mean? Studies indicate that it's already happening - oceans rising and an increased incidence and severity of droughts and floods. Like the floods the Midwest experienced in the nineties. Like the drought we in the Northeast are heading into right now.

Maybe it is a big deal after all.

Sources: nytimes.com; theturtlepages.crosswinds.net

by Kezia Bacon Bernstein, Correspondent
April 2002

Kezia Bacon Bernstein's articles appear courtesy of the North and South Rivers Watershed Association, a local non-profit organization devoted to the preservation, restoration, maintenance and conservation of the North and South Rivers and their watershed. For membership information and a copy of their latest newsletter, contact NSRWA at (781) 659-8168.

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