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Global
Warming: Man-Made or Natural?
August 2007 S. Fred Singer Professor Emeritus of Environmental Sciences, University of Virginia
The following is adapted from a lecture delivered on the Hillsdale College campus on June 30, 2007, during a seminar entitled “Economics and the Environment,” sponsored by the Charles R. and Kathleen K. Hoogland Center for Teacher Excellence.
This is
not to say that we don’t face a serious problem. But
the problem is political. Because of the mistaken idea that governments
can and
must do something about climate, pressures are building that have the
potential
of distorting energy policies in a way that will severely damage
national
economies, decrease standards of living, and increase poverty. This
misdirection of resources will adversely affect human health and
welfare in
industrialized nations, and even more in developing nations. Thus it
could well
lead to increased social tensions within nations and conflict between
them. If not for this economic and political damage, one might consider the present concern about climate change nothing more than just another environmentalist fad, like the Alar apple scare or the global cooling fears of the 1970s. Given that so much is at stake, however, it is essential that people better understand the issue. Man-Made Warming? The most
fundamental question is scientific: Is the observed
warming of the past 30 years due to natural causes or are human
activities a
main or even a contributing factor? At first
glance, it is quite plausible that humans could be
responsible for warming the climate. After all, the burning of fossil
fuels to
generate energy releases large quantities of carbon dioxide into the
atmosphere. The CO2 level has been increasing steadily since the
beginning of
the industrial revolution and is now 35 percent higher than it was 200
years
ago. Also, we know from direct measurements that CO2 is a “greenhouse
gas”
which strongly absorbs infrared (heat) radiation. So the idea that
burning
fossil fuels causes an enhanced “greenhouse effect” needs to be taken
seriously. But in
seeking to understand recent warming, we also have to
consider the natural factors that have regularly warmed the climate
prior to
the industrial revolution and, indeed, prior to any human presence on
the
earth. After all, the geological record shows a persistent 1,500-year
cycle of
warming and cooling extending back at least one million years. In
identifying the burning of fossil fuels as the chief
cause of warming today, many politicians and environmental activists
simply
appeal to a so-called “scientific consensus.” There are two things
wrong with
this. First, there is no such consensus: An increasing number of
climate
scientists are raising serious questions about the political rush to
judgment
on this issue. For example, the widely touted “consensus” of 2,500
scientists
on the United Nations Intergovernmental Panel on Climate Change (IPCC)
is an
illusion: Most of the panelists have no scientific qualifications, and
many of
the others object to some part of the IPCC’s report. The Associated
Press
reported recently that only 52 climate scientists contributed to the
report’s
“Summary for Policymakers.” Likewise, only about a dozen members of the governing board voted on the “consensus statement” on climate change by the American Meteorological Society (AMS). Rank and file AMS scientists never had a say, which is why so many of them are now openly rebelling. Estimates of skepticism within the AMS regarding man-made global warming are well over 50 percent.
But aren’t
glaciers melting? Isn’t sea ice shrinking? Yes,
but that’s not proof for human-caused warming. Any kind of warming,
whether
natural or human-caused, will melt ice. To assert that melting glaciers
prove
human causation is just bad logic. What about
the fact that carbon dioxide levels are
increasing at the same time tempera-tures are rising? That’s an
interesting
correlation; but as every scientist knows, correlation is not
causation. During
much of the last century the climate was cooling while CO2 levels were
rising.
And we should note that the climate has not warmed in the past eight
years,
even though greenhouse gas levels have increased rapidly. What about
the fact—as cited by, among others, those who
produced the IPCC report—that every major greenhouse computer model
(there are
two dozen or so) shows a large temperature increase due to human
burning of
fossil fuels? Fortunately, there is a scientific way of testing these
models to
see whether current warming is due to a man-made greenhouse effect. It
involves
comparing the actual or observed pattern of warming with the warming
pattern
predicted by or calculated from the models. Essentially, we try to see
if the “finger-prints”
match—“fingerprints” meaning the rates of warming at different
latitudes and
alti-tudes. For
instance, theoretically, greenhouse warming in the
tropics should register at increasingly high rates as one moves from
the
surface of the earth up into the atmosphere, peaking at about six miles
above
the earth’s surface. At that point, the level should be greater than at
the
surface by about a factor of three and quite pronounced, according to
all the
computer models. In reality, however, there is no increase at all. In
fact, the
data from balloon-borne radiosondes show the very opposite: a slight
decrease
in warming over the equator. The fact
that the observed and predicted patterns of warming
don’t match indicates that the man-made greenhouse contribution to
current
temperature change is insignificant. This fact emerges from data and
graphs
collected in the Climate Change Science Program Re-port 1.1, published
by the
federal government in April 2006 What
explains why greenhouse computer models predict
temperature trends that are so much larger than those observed? The
answer lies
in the proper evaluation of feedback within the models. Remember that
in
addition to carbon dioxide, the real atmosphere con-tains water vapor,
the most
powerful greenhouse gas. Every one of the climate models calculates a
significant positive feedback from water vapor—i.e., a feedback that
amplifies
the warming effect of the CO2 increase by an average factor of two or
three.
But it is quite possible that the water vapor feedback is negative
rather than
positive and thereby reduces the effect of increased CO2. There are several ways this might occur. For example, when increased CO2 produces a warming of the ocean, a higher rate of evaporation might lead to more humidity and cloudiness (provided the atmosphere contains a sufficient number of cloud condensation nuclei). These low clouds reflect incoming solar radiation back into space and thereby cool the earth. Climate researchers have discovered other possible feedbacks and are busy evaluating which ones enhance and which diminish the effect of increasing CO2. Natural Causes of Warming A quite
different question, but scientifically interesting,
has to do with the natural factors influencing climate. This is a big
topic
about which much has been written. Natural factors include continental
drift
and mountain-building, changes in the Earth’s orbit, volcanic
erup-tions, and
solar variability. Different factors operate on different time scales.
But on a
time scale important for human experience—a scale of decades, let’s
say—solar
variability may be the most important. Solar
influence can manifest itself in different ways:
fluctuations of solar irradiance (total energy), which has been
measured in
satellites and related to the sunspot cycle; variability of the
ultraviolet
portion of the solar spectrum, which in turn affects the amount of
ozone in the
stratosphere; and variations in the solar wind that modulate the
intensity of
cosmic rays (which, upon impact into the earth’s atmosphere, produce
cloud
condensation nuclei, affecting cloudiness and thus climate). Scientists
have been able to trace the impact of the sun on
past climate using proxy data (since thermometers are relatively
modern). A
conventional proxy for temperature is the ratio of the heavy isotope of
oxygen,
Oxygen-18, to the most common form, Oxygen-16. A paper published in Nature in 2001 describes the Oxygen-18 data (reflecting temperature) from a stalagmite in a cave in Oman, covering a period of over 3,000 years. It also shows corresponding Carbon-14 data, which are directly related to the intensity of cosmic rays striking the earth’s atmosphere. One sees there a remarkably detailed correlation, almost on a year-by-year basis. While such research cannot establish the detailed mechanism of climate change, the causal connection is quite clear: Since the stalagmite temperature cannot affect the sun, it is the sun that affects climate. Policy Consequences If this line of reasoning is correct, human-caused increases in the CO2 level are quite insignificant to climate change. Natural causes of climate change, for their part, cannot be controlled by man. They are unstoppable. Several policy consequences would follow from this simple fact: > Regulation of CO2 emissions is
pointless and even
counterproductive, in that no matter what kind of None of this is intended to argue against energy conservation. On the contrary, conserving energy reduces waste, saves money, and lowers energy prices—irrespective of what one may believe about global warming. Science vs. Hysteria You will
note that this has been a rational discussion. We
asked the important question of whether there is appreciable man-made
warming
today. We presented evidence that indicates there is not, thereby
suggesting
that attempts by governments to control green house gas emissions are
pointless
and unwise. Nevertheless, we have state governors calling for CO2
emissions
limits on cars; we have city mayors calling for mandatory CO2 controls;
we have
the Supreme Court declaring CO2 a pollutant that may have to be
regulated; we
have every industrialized nation (with the exception of the U.S. and
Australia)
signed on to the Kyoto Protocol; and we have ongoing international
demands for
even more stringent controls when Kyoto expires in 2012. What’s going
on here? To begin,
perhaps even some of the advocates of these
anti-warming policies are not so serious about them, as seen in a
feature of
the Kyoto Protocol called the Clean Development Mechanism, which allows
a CO2
emitter—i.e., an energy user—to support a fanciful CO2 reduction scheme
in
developing nations in exchange for the right to keep on emitting CO2
unabated.
“Emission trading” among those countries that have ratified Kyoto
allows for
the sale of certificates of unused emission quotas. In many cases, the
initial
quota was simply given away by governments to power companies and other
entities, which in turn collect a windfall fee from consumers. All of
this has
become a huge financial racket that could someday make the UN’s “Oil
for Food”
scandal in Iraq seem minor by comparison. Even more fraudulent, these
schemes
do not reduce total CO2 emissions—not even in theory. It is also
worth noting that tens of thousands of interested
persons benefit directly from the global warming scare—at the expense
of the
ordinary consumer. Environmental organizations globally, such as
Greenpeace,
the Sierra Club, and the Environmental Defense Fund, have raked in
billions of
dollars. Multi-billion-dollar government subsidies for useless
mitigation
schemes are large and growing. Emission trading programs will soon
reach the
$100 billion a year level, with large fees paid to brokers and those
who
operate the scams. In other words, many people have discovered they can
benefit
from climate scares and have formed an entrenched interest. Of course,
there
are also many sincere believers in an impending global warming
catastrophe,
spurred on in their fears by the growing number of onesided books,
movies, and
media coverage. The irony
is that a slightly warmer climate with more carbon
dioxide is in many ways beneficial rather than damaging. Economic
studies have
demonstrated that a modest warming and higher CO2 levels will increase
GNP and
raise standards of living, primarily by improving agriculture and
forestry.
It’s a well-known fact that CO2 is plant food and essential to the
growth of
crops and trees—and ultimately to the well-being of animals and humans. You wouldn’t know it from Al Gore’s An Inconvenient Truth, but there are many upsides to global warming: Northern homes could save on heating fuel. Canadian farmers could harvest bumper crops. Greenland may become awash in cod and oil riches. Shippers could count on an Arctic shortcut between the Atlantic and Pacific. Forests may expand. Mongolia
could become an economic superpower. This is all
speculative, even a little facetious. But still, might there be a
silver
lining for the frigid regions of Canada and Russia? “It’s not that
there won’t
be bad things happening in those countries,” economics professor Robert
O.
Mendelsohn of the Yale School of Forestry & Environmental Studies
says.
“But the idea is that they will get such large gains, especially in
agriculture, that they will be bigger than the losses.” Mendelsohn has
looked
at how gross domestic product around the world would be affected under
different warming scenarios through 2100. Canada and Russia tend to
come out as
clear gainers, as does much of northern Europe and Mongolia, largely
be-cause
of projected increases in agricultural production. To repeat a point made at
the beginning: Climate has been
changing cyclically for at least a million years and has shown huge
variations
over geological time. Human beings have adapted well, and will continue
to do
so.
* * * * * * * The nations of the world
face many difficult problems. Many
have societal problems like poverty, disease, lack of sanitation, and
shortage
of clean water. There are grave security problems arising from global
terrorism and the proliferation of nuclear weapons. Any of these
problems are
vastly more important than the imaginary problem of man-made global
warming.
It is a great shame that so many of our resources are being diverted
from real
problems to this non-problem. Perhaps in ten or 20 years this will
become
apparent to everyone, particularly if the climate should stop warming
(as it
has for eight years now) or even begin to cool.
We can only trust that reason will prevail in the face of an onslaught of propaganda like Al Gore’s movie and despite the incessant misinformation generated by the media. Today, the imposed costs are still modest, and mostly hidden in taxes and in charges for electricity and motor fuels. If the scaremongers have their way, these costs will become enormous. But I believe that sound science and good sense will prevail in the face of irrational and scientifically baseless climate fears. |