One of the great paradoxes of global warmning in the geological past of
the planet is that each episode has led to another ice age. In very
simple terms, what happens is that the polar ice caps melt with rising
atmospheric temperatures, releasing vast quantities of cold water into
the major ocean currents of the world. These currents cool down the
middle lattitudes of the planet even as the polar regions continue to
warm up. With cooler mid-lattitude temperatures, more snow falls each
winter, and the melt-off takes place later each spring, until, finally,
the time comes when the winter's accummulation does not entirely
disappear the following summer - and the glaciers begin to form once
again. Ironically, the glaciers will cover the mid-lattitudes even
while the polar oceans remain open - at least for a time.
This is not of immediate concern, although the geological record tells
us that the process is amazingly rapid once it is fully under way. I
mention it at this time to underline the complexity of the topic that
we call "Global Warming" and to illustrate that, like so many things in
the natural world, we have only a superficial understanding of the
entire process.
What is of immediate concern is what we are going to do about the next
fifty years or so.
As I write this, it is early October. In the more than thirty years
that Carla and I have been growing most of our own vegetables, this is
the latest we have ever gone without frost. I realize that we benefit
from the "heat sink" in our front yard - the Restigouche Estuary - and
that others, back inland just a kilometer or so, have had frost; but
even there, they have not had the killing cold that was to be expected
by early October even five or six years ago. In the spring, we know
that we can plant some cold-tolerant crops with relative impunity even
in early May. We have not had a late hard frost to set such crops back
in several years. In all, our growing season has expanded by several
weeks. This summer we had a good crop of melons, all field ripened; by
far the best crop of grapes ever (until the robins discovered them),
field ripened tomatoes, peppers, and other crops that until very
recently we had to regard as "occasional." I would be a liar if I said
that I did not enjoy this "softening" of the seasons.
And yet, I am somewhat alarmed by it, especially when I think beyond my
own narrow world into the larger one, "out there". There are those who
have said to me, "No problem - we will simply be able to farm further
north" as though potato fields will blossom in the tundra of northern
Quebec or Labrador and corn will flourish in the Gaspe Mountains. But
there is a fundamental problem with this optimistic view and that is
that, even with adequate warmth and moisture, it will take hundreds of
years for soil to develop on the rocks and muskeg to grow such crops.
In the past, as glaciers retreated, plants followed as soil was
released and built up; like most things in the natural world, this was
a slow and rather stately process.
In the current scenario, we are pushing things so quickly that natural
systems cannot keep up, with the horrific certainty that our present
agricultural lands will be destroyed by heat and drought ( and that is
already happening, all over the world) long before northern soils will
be ready to take their productive places. Every proposal to avert
potential disaster, such as massive irrigation projects, can only work
in the short term, while contributing to the problem in the longer
term.
Last week, I suggested that many people have shifted from thinking in
terms of "if" to "when". I think that it is imperative that we all do,
because it is only then that we can begin to make plans to counteract
the worst consequences that our immediate descendants - our children,
grandchildren and theirs - will face. We may not be able to stop what
is, perhaps after all, a natural process, but we can slow its progress
so that it resumes its normal pace. In so doing, we will give our
descendants critical time to work toward their own solutions. Perhaps
we may even rediscover the essential importance of living in some sort
of equilibrium with the world around us.
At the very least, I would like to think that our descendants looked
back on us as people who cared, who recognized their mistakes and who
began to work toward some solutions to them. I shudder to think of how
they will regard us if we don't even try.
This article appeared in the Campbellton Tribune, in Mike's "Grains of Sand" column.
It is reproduced with Mike's permission.
Global Warming! part two...