by Michael Nunziata
Compared with the extreme weather of last year, this winter in the Mid-Hudson Valley has been a walk in the park so far. Here it is February and we’ve hardly seen snow. Last winter, the ground hid itself under a mattress of snow the day before Thanksgiving and refused to emerge until April. That was trial enough. But the thing I remember most clearly was February’s appalling and relentless cold. It seemed to take on almost a solid quality, like a downpour of iron nails. Freezing blasts of wind roared for weeks on end, and the thermometer fell to -10, -20, -30. I broke two shovels and began to believe that a new Ice Age had dawned. But unless one has, this winter in total will be milder than last year’s, however Arctic it may turn.
An Ice Age is defined as a glacial epoch, an age of glaciers; a long bracket of time when earth’s average temperature drops below freezing and stays there; an entire age when water has turned into ice. The most recent Ice Age kicked off roughly 110,000 years ago and only ended around 12,000 or so years ago—an unbroken run of more than a thousand centuries, or over a hundred millenia! (After last winter, I’m amazed to learn that we humans lived through it from start to finish. But we did.) Glaciers themselves are enormous masses of freshwater ice formed by compressed layers of long-accumulated snows. Icebergs belong to glaciers; they are simply the glaciers’ shivered edges, giant crystal ice cubes of Mother Earth’s purest water plunked down in the swirling, margarita-salt seas.
|A glacier in Greenland.
Those same salt seas and oceans hold nearly all the planet’s water: 97.5 percent of it, according to the United States Geological Survey. Freshwater makes up the leftover 2.5 percent. Glaciers and ice-caps are nature’s freshwater reservoirs, locking up about two-thirds of the earth’s freshwater supply. Incidentally, “freshwater” simply means water that is not saltwater. It does not mean that all freshwater is somehow fit to drink: due to poor soils, bad toxins and even worse practices in many parts of the world, much of it isn’t. But the water in glaciers and ice-packs is some of the purest water left on the Earth.
The remaining one-third of freshwater includes all the water in lakes, rivers, swamps, ground ice, permafrost, and groundwater deposits. It also includes the moisture in the atmosphere and in the soil, and even the water sloshing around within the confines of all living things. When you reflect that groundwater alone accounts for nearly the whole of this last portion of freshwater, when you try and work out the tiny, tiny fractions left over for rivers and lakes and raindrops and so on—the sources of biological life—you begin to see the incalculable worth and fragility of this remarkable and dwindling resource.
Glaciers cover one-tenth of earth’s surface, and are found on every continent except Australia. In the US, hundreds of glaciers dot the Pacific Coast ranges and Rocky Mountain States. Alaska alone boasts over 500 glaciers. There’s one in Nevada and still another as far south as California’s Central Valley. But we haven’t any glaciers of our own in New York State, not since the departure of the great Laurentide ice sheet, though its marks are all around us.
An ice sheet is a type of glacier, an enormous continental expanse of snow and ice. Only two ice sheets—in Greenland and Antarctica—still remain. At the height of the last Ice Age, the Laurentide spread from central Canada across the northeastern United States, stretching one long cold finger down the Hudson canyon, a deep gash in the earth left over from a still-earlier convulsion. The finger dug in its nail as it pushed down through New York State, gouging out Niagara Falls and the Finger Lakes and piling ahead of it enough rock and sand to create Manhattan and Long Island. At the end of the Ice Age the Laurentide melted away, leaving a trail across the state of pulverized stone and gravel, a perfect medium for aquifers and a splendid mineral base for our incomparable soils.
Nearly all of the world’s glaciers are shrinking. Sea-level rise projections for sustained glacial meltdown wander all over the chart: some experts say 40 feet; others say 60 or even 100. Less soothing is the news that such a frigid deluge might somehow dilute the warm Gulf Stream currents, bringing on a global cooling trend that would make last winter in New York feel like August in Miami.
Michael Nunziata practices water law in New York State.