We know from earlier civilizations that the lead indicators of economic
decline were environmental, not economic. The trees went first, then the
soil, and finally the civilization itself. To archeologists, the
sequence is all too familiar.
Our situation today is far more challenging because in addition to
shrinking forests and eroding soils, we must deal with falling water
tables, more frequent crop-withering heat waves, collapsing fisheries,
expanding deserts, deteriorating rangelands, dying coral reefs, melting
glaciers, rising seas, more-powerful storms, disappearing species, and,
soon, shrinking oil supplies. Although these ecologically destructive
trends have been evident for some time, and some have been reversed at
the national level, not one has been reversed at the global level.
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In a rather ingenious approach to calculating the human physical
presence on the planet, Paul MacCready, the founder and Chairman of
Aerovironment and designer of the first solar-powered aircraft, has
calculated the weight of all vertebrates on the land and in the air. He
notes that when agriculture began, humans, their livestock, and pets
together accounted for less than 0.1 percent of the total. Today, he
estimates, this group accounts for 98 percent of the earth's total
vertebrate biomass, leaving only 2 percent for the wild portion, the
latter including all the deer, wildebeests, elephants, great cats,
birds, small mammals, and so forth.
Ecologists are intimately familiar with the overshoot-and-collapse
phenomenon. One of their favorite examples began in 1944, when the Coast
Guard introduced 29 reindeer on remote St. Matthew Island in the Bering
Sea to serve as the backup food source for the 19 men operating a
station there. After World War II ended a year later, the base was
closed and the men left the island. When U.S. Fish and Wildlife Service
biologist David Kline visited St. Matthew in 1957, he discovered a
thriving population of 1,350 reindeer feeding on the thick mat of lichen
that covered the 332-square-kilometer (128-square-mile) island. In the
absence of any predators, the population was exploding. By 1963, it had
reached 6,000. He returned to St. Matthew in 1966 and discovered an
island strewn with reindeer skeletons and not much lichen. Only 42 of
the reindeer survived: 41 females and 1 not entirely healthy male. There
were no fawns. By 1980 or so, the remaining reindeer had died off.
Like the deer on St. Matthew Island, we too are over-consuming our
natural resources. Overshoot leads sometimes to decline and sometimes to
a complete collapse. It is not always clear which it will be. In the
former, a remnant of the population or economic activity survives in a
resource-depleted environment. For example, as the environmental
resource base of Easter Island in the South Pacific deteriorated, its
population declined from a peak of 20,000 several centuries ago to
today's population of fewer than 4,000. In contrast, the 500-year-old
Norse settlement in Greenland collapsed during the 1400s, disappearing
entirely in the face of environmental adversity. . .
You do not need to be an ecologist to see that if recent environmental
trends continue, the global economy eventually will come crashing down.
It is not knowledge that we lack. At issue is whether national
governments can stabilize population and restructure the economy before
time runs out.