http://www.commondreams.org/views02/0301-02.htm
Published on Friday,
March 1, 2002 in the Guardian of London
Goodbye Cruel World
A Report by Top US Scientists on Climate Change
Suggests That Catastrophe Could Be Imminent
by Jeremy Rifkin
We live in a world that has become so desensitised by watching
calamities unfold on global television - both natural and
human-induced - that it takes something really spectacular
even to get our attention.
And it usually has
to be visually dramatic to register, much less
elicit a deep emotional response - such as the tragic events of
September 11.
Recently, I came across
a frightening report published by the
US National Academy of Sciences (NAS) - the nation's most august
scientific body. Yet, because there was no visually provocative
content, the report had received only a couple of short paragraphs
tucked away inside a few newspapers.
Here is what the academy
had to say: it is possible that the
global warming trend projected over the course of the next
100 years could, all of a sudden and without warning, dramatically
accelerate in just a handful of years - forcing a qualitative
new climatic regime which could undermine ecosystems and human
settlements throughout the world, leaving little or no time for
plants, animals and humans to adjust.
The new climate could
result in a wholesale change in the
earth's environment, with effects that would be felt for
thousands of years. If the projections and warnings in this
study turn out to be prophetic, no other catastrophic event
in all of recorded history will have had as damaging an impact
on the future of human civilisation and the life of the planet.
A year ago the UN intergovernmental
panel on climate change
(IPCC) issued a voluminous report forecasting that global average
surface temperature is likely to rise by 1.4 to 5.8 degrees
centigrade between now and 2100. If that projection holds up,
we were told, the change in temperature forecast for the next
100 years will be larger than any climate change on earth in
more than 10,000 years.
The impacts on the
earth's biosphere are going to be of a
qualitative kind. To understand how significant this rise
in temperature is likely to be, we need to keep in mind
that a 5 degrees centigrade increase in temperature between
the last ice age and today resulted in much of the northern
hemisphere of the planet going from being buried under
thousands of feet of ice to being ice-free.
The UN study predicts
that a temperature rise of
1.4-5.8 degrees centigrade over the course of the
coming century could include the melting of glaciers
and the Arctic polar cap, sea water rise, increased
precipitation and storms and more violent weather patterns,
destabilisation and loss of habitats, migration northward
of ecosystems, contamination of fresh water by salt water,
massive forest dieback, accelerated species extinction and
increased droughts.
The IPCC report also
warns of adverse impacts on human
settlements, including the submerging of island nations
and low-lying countries, diminishing crop yields, especially
in the southern hemisphere, and the spread of tropical
disease northward into previously temperate zones.
The newly released
NAS report begins by noting that the
current projections about global warming and its ecological,
economic and social impacts cited in the UN report are
based on the assumption of a steady upward climb in
temperatures, more or less evenly distributed over the
course of the 21st century. But that assumption, they say,
may be faulty - there is a possibility that temperatures
could rise suddenly in just a few years' time, creating a
new climatic regime virtually overnight.
They also point out
that abrupt changes in climate, whose
effects are long lasting, have occurred repeatedly in the
past 100,000 years. For example, at the end of the
Younger-Dryas interval about 11,500 years ago, "global
climate shifted dramatically, in many regions by about
one-third to one-half the difference between ice age and
modern conditions, with much of the change occurring over
a few years".
According to the study:
"An abrupt climate change occurs
when the climate system is forced to cross some threshold,
triggering a transition to a new state at a rate determined
by the climate system itself and faster than the cause."
Moreover, the paleoclimatic record shows that "the most
dramatic shifts in climate have occurred when factors
controlling the climate system were changing". Given the
fact that human activity - especially the burning of
fossil fuels - is expected to double the CO<->2 content
emitted into the atmosphere in the current century, the
conditions could be ripe for an abrupt change in climate
around the world, perhaps in only a few years.
What is really unnerving
is that it may take only a slight
deviation in boundary conditions or a small random fluctuation
somewhere in the system "to excite large changes ... when
the system is close to a threshold", says the NAS committee.
An abrupt change in
climate, of the kind that occurred during
the Younger-Dryas interval, could prove catastrophic for
ecosystems and species around the world. During that particular
period, for instance, spruce, fir and paper birch trees
experienced mass extinction in southern New England in less
than 50 years. The extinction of horses, mastodons, mammoths,
and sabre-toothed tigers in North America were greater at
that time than in any other extinction event in millions
of years.
The committee lays
out a potentially nightmarish scenario
in which random triggering events take the climate across
the threshold into a new regime, causing widespread havoc
and destruction.
Ecosystems could collapse
suddenly with forests decimated
in vast fires and grasslands drying out and turning into
dust bowls. Wildlife could disappear and waterborne diseases
such as cholera and vector-borne diseases such as malaria,
dengue and yellow fever, could spread uncontrollably beyond
host ranges, threatening human health around the world.
The NAS concludes its
report with a dire warning: "On the
basis of the inference from the paleoclimatic record, it is
possible that the projected change will occur not through
gradual evolution, proportional to greenhouse gas concentrations,
but through abrupt and persistent regime shifts affecting
subcontinental or larger regions - denying the likelihood or
downplaying the relevance of past abrupt changes could be costly."
Global warming represents
the dark side of the commercial ledger
for the industrial age. For the past several hundred years,
and especially in the 20th century, human beings burned massive
amounts of "stored sun" in the form of coal, oil and
natural
gas, to produce the energy that made an industrial way of
life possible. That spent energy has accumulated in the
atmosphere and has begun to adversely affect the climate
of the planet and the workings of its many ecosystems.
If we were to measure
human accomplishments in terms of
the sheer impact our activities have had on the life of
the planet, then we would sadly have to conclude that global
warming is our most significant accomplishment to date,
albeit a negative one.
We have affected the
biochemistry of the earth and we have
done it in less than a century. If a qualitative climate
change were to occur suddenly in the coming century - within
less than 10 years - as has happened many times before in
geological history, we may already have written our epitaph.
When future generations
look back at this period, tens of
thousands of years from now, it is possible that the only
historical legacy we will have left them in the geologic
record is a great change in the earth's climate and its
impact on the biosphere.
Jeremy Rifkin is the
author of The Biotech Century (Gollancz)
and president of the Foundation on Economic Trends in Washington
DC
© Guardian Newspapers
Limited 2002
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