Goodbye cruel world: A report by top US scientists on climate change
suggests that catastrophe could be imminent
Jeremy Rifkin
Friday March 1, 2002
The Guardian
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
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