The Great Lakes myth
A new Great Lakes water study has come out and it has some very interesting things to say about the changes that we are about to experience as global warming heats up the heartland of Canada and the US.
As you may know, we use prodigious amounts of glacial water to irrigate the dry middle region of North America. Our combined population of some 300 million souls is fed from the corn and other grains grown in the heartland that supports the plant and animal agribusiness of both Canada and the US. And it can only be done with water. Some of it comes from rivers that flow from the north, where winter traps snow and then releases it in the spring melt. Most of it comes from the ground. There is a vast aquifer, the Ogallala Aquifer that exists under the states of Nebraska, the Dakotas, Kansas and Colorado. This is very old water, coming from the melt of the vast Ice Sheets that covered much of North America during the last ice advance and has been there for more than ten thousand years. It is now being pumped out of the ground in prodigious amounts to support agribusiness and irrigate the vast grain tracts of the midwest. Hydrologists tells its days are numbered because there is nothing replace the water that is pumped out. And while necessary to support the food production that feeds us, we are rushing headlong into times when the glacial paleowater is no longer there for the taking.
This is not new news. It has been known that this situation is not sustainable for a number of decades. The backup plan, diverting some of the huge Great Lakes water into the drier states, as the aquifer dries up, has been also kicked around and has been the source of much fretting and hand wringing. And with good reason. Mess with watersheds and you may get more than you bargained for. Back in the 1960s, the former Soviet Union, in one of its infamous cash crunches, decided to divert a few of the rivers that supplied the mighty Aral Sea, then the fourth largest lake body in the world, to supply water to grow cotton and bring in much needed money into the economy. In a decade the Aral Sea shrank to a fraction of its former size, creating massive salt plains from the evaporate, which then blew in to the surrounding region with a vengeance, poisoning a huge area with salt, including the planned cotton growing regions. The Aral Sea never recovered and today you would think hydrologists would have learned a few things because of that.
But business is business and Great Lakes water diversion schemes continue to rear their ugly heads. In the face of that comes a new study. This one, one hopes will give us pause. It appears that the much vaunted water of the Great Lakes, one of the largest supplies of the stuff anywhere in the world, are also remnants of that last Ice Age, and are in an agonizingly slow replenishment cycle. It takes more than one hundred years to replace the water in the lakes from the natural cycle of rain, snow melt and inflow. Any diversion would widen water area and increase the already tortoiselike replenishment time. And because we have now witnessed reduced inflow rates and increased evaporation rates because of climate change even these numbers are not static and exacerbate the slow destabilization of an already fragile balance.
So we are caught in a bind. We cannot live without food and daily the number of mouths to feed are increasing. And all the while we continue, business as usual, floating plans that would put us at further risk, while we pretend that we can ignore the facts.
Water is precious and not just a commodity to be treated as though it is in infinite supply. We must begin to manage our population, our wants and our greed, the changes are coming whether we like it or not.
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