Climate Corrections |
By SYUN-ICHI AKASOFU
Copyright 2007 WSJ, link to free preview: http://online.wsj.com/article/SB118954539363624201.html
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Climate change reared its head again last week at the Asia-Pacific Economic
Cooperation summit in Sydney, where participating heads of state struggled to
reach a consensus on how to reduce emissions of carbon dioxide (CO2). The
political squabbling, global warming true believers will say, stands in stark
contrast to the scientific consensus that the greenhouse effect, a product of
increasing CO2 in the atmosphere, is causing dramatic climate change. There's
just one problem with this view: There's a lot less to that "scientific
consensus" than meets the eye.
When millennial climate change patterns are mentioned, many people point to the
"2,500 scientists from 130 countries" who have agreed that global
warming is caused by the greenhouse effect. Yet not even the International Panel
of Climate Change to which these people refer presents definitive scientific
proof that the present warming is mostly caused by the greenhouse effect. It is
simply an assumption that has morphed into a fact.
Since the physics behind CO2's greenhouse effect has long been well known, the
IPCC made the assumption that post-1900 warming was caused by it. They assembled
a large number of scientists, mostly meteorologists and physicists (but,
interestingly, not many climatologists), and tried to prove their hypothesis
using supercomputer models. They have continued to work in this way despite
important new evidence from ice-core data showing that temperature rises tend to
precede CO2 increases by about 1,000 years. With all of the media attention that
this assumption now enjoys, natural temperature changes have been mostly
forgotten. Yet in reality they persist; they're simply not being studied. This
is the single greatest failing of the IPCC.
Meanwhile, a tree-ring study that was conducted to estimate historical
temperatures was published in 1999. It showed that over the years, global
temperatures had decreased gradually between the years 1000 and 1900, at which
time they suddenly began to increase. Its graph was nicknamed "the hockey
stick" because of its shape and it has been prominently displayed in the
summary of the IPCC's 2001 report.
After glancing at this figure, many policy makers, environmental advocacy groups
and scientists around the world were convinced that the greenhouse effect began
after 1900. But the hockey-stick graph was later discredited. Two Canadian
statisticians found that the authors of the graph made a statistical error in
dealing with the tree-ring data. After correcting the error, the two researchers
could not reproduce the sharp upturn of the curve -- even though they were using
the very same data.
In understanding the present warming trend, it is absolutely essential to learn
more about climate change in the distant past -- or at least during the last
1,000 years. But many scientists, particularly younger ones, prefer to work only
with data collected after 1975, when satellite data became available. With only
30 years worth of data, their results are little more than climatological
snapshots of what is really a slow, long-term process. The latest accurate
satellite images of sea ice distribution in the Arctic Ocean today can be
obtained by clicking on a computer screen; but it is impossible to obtain such
quality data for periods before 1975.
It is for this reason that only a minority of scientists are studying natural
climate change, including multi-decadal oscillations and centurial climate
change, which is the true realm of climatology. These areas have not been
priorities for the IPCC.
They should be. During winter, England's Thames River would once freeze solid.
This occurred on and off between 1400 and 1800 during a period called the
"Little Ice Age" when temperatures dropped by as much as 1.5 degrees
Celsius, which came after the medieval warm period around 1000. The
anomaly of the Little Ice Age corrected itself, of course, through something
called rebounding. The rebounding rate is estimated at 0.5 degrees Celsius per
century. Since our present warming rate is roughly 0.6 degrees Celsius per
century, the greenhouse effect caused by CO2 may represent only a 0.1 degree
Celsius increase in temperature over the course of a century.
There is no doubt that global warming is in progress. But much of it can be
attributed to the rebounding effect from the Little Ice Age. Recovering from a
cool period is, of course, warming -- but it is nothing to panic about. Ice core
data from the Greenland ice sheet show many periodic warming and cooling periods
during the last 10,000 years. The present warming phase is far from the warmest.
Scientists have no clear knowledge of the cause of the Little Ice Age and of the
subsequent rebound; or of the Big Ice Age; or of a warm period when the Arctic
Ocean had no ice; or of the medieval warming period. In fact, IPCC scientists do
not understand the causes of the rapid increase of temperature from 1910 to
1945; or the decrease from 1945 to 1975, when CO2 levels were rising. Without
understanding these recent changes, it is premature for the IPCC to jump to the
conclusion that CO2 is the main cause of the last 30 years of global warming.
Many people claim scientists proved the greenhouse effect with models run on
supercomputers. But a supercomputer is not a crystal ball. Scientists merely
enter observed (or expected) CO2 amounts into a computer and, using an
algorithm, a projection emerges. No computer can accurately represent such a
gigantic system as the Earth with all its unknown processes, such as the causes
of the medieval warm period and the Little Ice Age.
Therefore, no supercomputer, no matter how powerful, is able to prove
definitively a simplistic hypothesis that says the greenhouse effect is
responsible for warming. Most people, including scientists who specialize in
climatology, are not aware of this weakness. In fact, the whole science of
climate change based on supercomputers and algorithmic models is still in its
infancy. A supercomputer cannot provide an approximate
estimate of the temperature in 2050 or 2100 because scientists are not able to
instruct it with all the unknown processes that may be at play. Any conclusions
drawn from such results -- which may be seen as nothing more than an academic
exercise -- cannot and should not serve as hard facts on which to base major
international policies.
The booming Far East is home to a series of economies which have become the
factories of the developed world. This arrangement provides economic benefits
but also makes it impractical for Asian nations to reduce their CO2 output. In
fact, many political leaders in China have declared it hypocritical for the
Western world to make such a demand. A truly
environmentally friendly policy would invest in innovation -- in order to
increase energy efficiency -- and not try to stifle whole economies
by attempting to do away with CO2 based on faulty science and wild assumptions.
It would be better for Asian countries such as China, India and South Korea to
invest in researching nuclear fusion as a future energy source.
In the meantime, the integrity of climatology as a
respectable science has to be rehabilitated by bringing it back from its present
confused state and separating it entirely from politics. Only then
can real progress be made in predicting future climate patterns. At the same
time, environmental advocacy groups should return to their original goal of
protecting the environment from those things over which humanity truly does have
control.
Mr. Akasofu is the former director of the International Arctic Research
Center at the University of Alaska. This essay is adapted from an article
appearing in the Sept. 2007 issue of the Far Eastern Economic Review.
Copyright 2007 WSJ