Part
5: Warming
- Human Influence & Climate Simulation Models
August 21, 2001
by Bob Webster
The proponents
of human-induced "global warming" claim that human CO2
production (primarily through burning fossil fuels and deforestation
by fire) is responsible for dramatic increases in the greenhouse
gas, CO2, and that this increase is producing a significant
climate change (warming) that will cause great harm to our environment
during the next 100 years. In July 2001, the British newspaper
Independent wrote: "Global warming is happening now,
caused by human actions, and threatens the Earth with disaster
..."[1]. Climate change predictions
during the next 100 years are based on results from climate
computer simulation models known as "general circulation models"
(GCMs).
Part 5 of this series takes
a closer look at human activity and the production of CO2,
and the relatively crude state of climate modeling and basic
climate theory.
Warming - Human Influence
"Forty
years ago, when weather modification was popular speculation
in meteorology, some of the Soviet Union's generals realized
that the climate was always changing and that our ability to
modify it was minimal at best. The Soviet Union therefore agreed
on a treaty with the United States never to use climate modification
as a tool of warfare, thus (they hoped) preventing people from
mistaking the inevitable droughts, floods, heat waves and cold
spells for acts of aggression.
"The treaty displayed
an unusual and admirable appreciation for nature and concern
for mankind."[2]
Every so often it's worth reflecting
on how powerless humans are in their ability to seriously cause
harm to our planet. Efforts to control weather have proven fruitless,
yet we are asked to believe that we can accidentally alter our
climate by inducing strong and abnormal global warming as a
consequence of human industry. Ironically, many of the same
people advocating the human-induced global warming were at the
forefront of the "coming ice age" hysteria only a few decades
ago.
In his book New Earths,
James Edward Oberg describes techniques that could be used to
alter inhospitable planets so that they could sustain human
life in a natural environment. It is a volume worth reading
if you are tempted by the accidental global warming theories.
Oberg describes theoretical approaches to changing global climate
that contemporary humans could not begin to accomplish. Even
if climate drivers were perfectly understood, the capability
to alter the enormous complex of factors that work together
to produce climate is simply beyond the capability of humans.
Yet we are asked to believe that we are accidentally doing what
we cannot do deliberately. And if we grant humans this power
to alter climate accidentally, then shouldn't humans have the
power to alter climate to produce more favorable results ...
or are humans only capable of destructive power?
According to Oak Ridge National
Laboratory estimates, natural processes release about 200 billion
tons of carbon dioxide in the atmosphere each year (through
volcanic activity, natural forest fires, plant decay and the
oceans. Each year, natural processes remove about the
same amount of atmospheric CO2 through the actions
of ocean plankton, algae, chemical weathering of rock, plant
growth (primarily trees) and desert soil absorption. Only about
2% of the natural carbon cycle CO2 is present in
the atmosphere at any given time.[3]
Anthropogenic CO2
produced from burning fossil fuels and clearing forests by fire
produce only 7 to 8 billion tons per year (3%-4% of natural
CO2 production).[4]
Proponents of human-induced
global warming are quick to point out that the small contribution
of atmospheric CO2 from humans can create big problems.
They claim that the natural production/absorption cycle of CO2
is in equilibrium and that even small additional amounts from
human activity can have devastating climatic consequences.
In the chapter "Global Warmth"
in his book A Moment On The Earth, Gregg Easterbrook
answers this claim:
"Certainly
this is possible. But in making the assertion doomsayers leave
out a key modifier: The natural carbon cycle is in an approximate
equilibrium state. Ice-core records are clear on the point that
natural CO2 levels bounced up and down long before
the first flint struck steel. Into the approximate equilibrium
of the natural carbon cycle comes such natural perturbations
as periods of global volcanism, ice ages, droughts that reduce
carbon dioxide subtractions by land plants, weather vacillations
that cause rainy seasons and increase carbon dioxide subtractions
by land plants, and many other natural carbon-altering events.
In environmental orthodoxy, before the arrival of men and women
the Earth dwelled in a sort of Golden Era when all natural forces
ideally balanced. Surely there were individual centuries when
this was so; perhaps there were millennia. But at least in the
most recent four million years of Earth history, the period
of cyclical ice ages, the biosphere could hardly be described
as a placid equilibrium state."[5]
Bear in mind, too, that over
98% of greenhouse warming is due to water vapor and clouds.[6,7]
Less than 2% of greenhouse warming is due to the greenhouse
gas CO2. Human industry's contribution to the amount
of atmospheric CO2 present at any given time is not
known because we simply do not fully understand to what extent
increased atmospheric CO2 triggers natural balancing
forces to consume any excess CO2. For example, in
a paper produced by the Center for the Study of Carbon Dioxide
and Global Warming, C. D. Idso and K. E. Idso observe:
"It has
been shown ... that the warming predicted to result from a doubling
of the air's CO2 content may be totally countered
by: (1) a mere 1% increase in the reflectivity of the planet,
or (2) a 10% increase in the amount of the world's low-level
clouds, or (3) a 15 to 20% reduction in the mean droplet
radius of earth's boundary-layer clouds, or (4) a 20
to 25% increase in cloud liquid water content. In addition,
it has been demonstrated that the warming-induced production
of high-level clouds over the equatorial oceans almost totally
nullifies that region's powerful water vapor greenhouse effect,
which supplies much of the temperature increase in the CO2-induced
global warming scenario.
"Most of these
important negative feedbacks are not adequately represented
in state-of-the-art climate models. What is more, many related
(and totally ignored!) phenomena are set in motion when the
land surfaces of the globe warm. In response to the increase
in temperature between 25°N latitude and the equator,
for example, the soil-to-air flux of various sulfur gases
rises by a factor of 25, as a consequence of warmth-induced
increases in soil microbial activity; and this phenomenon
can lead to the production of more cloud condensation nuclei
just as biological processes over the sea do. Clearly, therefore,
any number of combinations of these several negative feedbacks
could easily thwart the impetus for warming provided by future
increase in the air's CO2 content."[8]
Nevertheless, it is safe to
say that, within the past 120 years, atmospheric levels of CO2
have risen considerably and much of that increase may be due
to burning of fossil fuels by human activity. Given this circumstance,
is it correct to conclude that human activity is responsible
for any increase observed in earth's global temperature? The
answer is a resounding "no."
If the premise that human activity
producing increased atmospheric CO2 causes significant
(and potentially "disastrous") global warming were true, then
a "cause and effect" relationship between increased atmospheric
CO2 and global temperature change should be easy
to demonstrate (using historical data from ice-core samples,
tree rings, etc.).
Can a "cause and effect" relationship
between changes in atmospheric CO2 and global temperature
change be demonstrated? Examine the following chart:
This chart shows a correlation
between atmospheric CO2 and global temperature changes.
However, a "correlation" does not demonstrate a "cause and effect"
relationship. To demonstrate a "cause and effect" relationship,
"it must be demonstrated that the presumed cause precedes
the presumed effect. Further, a single instance would prove
insufficient to assert the claim of a "cause and effect" relationship
-- evidence for such a relationship must be demonstrated over
several cycles of increases and decreases in both parameters."[9]
A close examination of the chart
shows each of the following:
Temperature increases predating
CO2 increases,
Temperature decreases predating
CO2 increases,
CO2 increases
predating temperature increases,
CO2 decreases
predating temperature increases,
To validate the global warming
alarmists' claim that a "cause and effect" relationship exists
between increased CO2 and increased global temperature,
a consistent relationship showing increased CO2 predating
(leading to) increased temperature (line 3. above) should be
evident. Yet no such consistency exists, and, in fact, there
is no consistent "cause and effect" linkage between the data.
While the data are correlated, the alarmists' claims that increased
atmospheric CO2 will definitely lead to a warmer
planet are simply not in evidence.
Climate Simulation
Apart from the inconvenience
that historical data do not support their claims, global warming
alarmists have to contend with the equally serious weakness
in their claims that current climate models can accurately predict
future global temperature with any meaningful accuracy. Global
warming alarmists' climate change predictions during the next
100 years are based on results from climate computer simulation
models known as "general circulation models" (GCMs). Even if
scientists understood the science of climate prediction well
enough to construct a proper simulation model (and they do not),
neither the requisite data nor the computational power exists
to accurately forecast future climate.
"...
one cannot even calculate the temperature of the Earth without
models that accurately reproduce the motions of the atmosphere.
Indeed, present models have large errors here -- on the order
of 50 percent. Not surprisingly, those models are unable to
calculate correctly either the present average temperature of
the Earth or the temperature ranges from the equator to the
poles. Rather, the models are adjusted or 'tuned' to get those
quantities approximately right."[10]
The July 23, 2001 edition of
Newsweek International featured an outstanding interview
with Dr. Lindzen by Fred Guterl in which "the crux of Lindzen's
beef with the global warming establishment" was very clearly
described:
"What
is the relationship between nature, on the one hand, and the
gigantic computer models that churn out climate predictions
for 100 years hence? 'In the scientific methodology,' he says,
'simulation is the weakest link. To say you’ve simulated something
is to say very little.' To appreciate why requires a brief foray
into the world of climate science.
"When it comes
to meteorology, data can be very iffy. The United Nations
specifies that thermometer readings in harsh polar climates,
for instance, should be taken in a shelter that is freshly
painted, of a specified height, ventilated in a certain way
and so forth. When the Soviet Union fell and Siberian data
collectors stopped being paid, did they continue to maintain
the shelters? In the oceans, sometimes data collectors take
the temperature of water drawn in a bucket over the side of
a ship. Other times they put their thermometers in the water
that enters the ship’s engine intakes. Such inconsistent practices
may have something to do with why observations show a warming
at the North Pole but not at the South, while some areas even
seem to be cooling. The overall warming trend of 0.6 degrees
centigrade in the past 100 years is just discernible above
these messy readings. 'The observations are not great, but
there’s a consistency in the trend,' Lindzen says.
"Back in the
1980s, climate models were very crude simulations of the greenhouse
effect. The main test of a climate model is to start sometime
in the past and 'predict' the present, with all the temperature
swings and ice ages and so forth in between. When scientists
tried this out on their early models, they got silly results,
such as severe ice ages occurring in the 20th century. To
avoid this kind of 'drift,' scientists applied a sort of fudge
factor to ensure a sensible outcome. This doesn’t do much
good when it comes to predicting the future, which may be
why 1988 predictions of rapid warming by 2000 never panned
out. The average temperature hasn’t climbed at all.
"In recent years
climate scientists have added a great deal of complexity to
their models in the hope of capturing the essential behavior
of the earth’s climate. They have tried to account for clouds,
water vapor, ocean currents, dust particles in the air (aerosols),
sea ice and variations in ground cover. They have coupled
the oceans to the atmosphere so that changes in one affect
the other, and vice versa. Only recently have the better models,
such as that of the Hadley Centre in Britain, abandoned the
practice of fudging.
"Adding A
Fudge Factor
"The change adds
to the models’ credibility, but does it mean they are reliable
in predicting the future? It doesn’t, Lindzen argues. For
one thing, added complexity does not ensure that the models
reflect what nature is doing. Take the case of aerosols—dust
and other particles in the atmosphere. Scientists realized
only a few years ago that aerosols reflect light and may exert
a cooling influence; their effects are poorly understood.
Putting them in climate models is essentially the same thing
as adding a fudge factor. 'There are no records of aerosol
production before the 1960s,' Lindzen says. 'So you have complete
freedom to adjust the amount of aerosols to make the models
replicate the temperature record.'
"Aerosols are
small potatoes when you consider the effects of clouds and
water vapor. Water vapor is a far more powerful greenhouse
gas than carbon dioxide — a change of a few percentage points
in the atmosphere’s humidity could wipe out, or amplify, the
effects of a rise in carbon dioxide. Even a doubling of carbon
dioxide from preindustrial levels (which [the 'business as
usual' scenario predicts will] happen in 100 years if no effort
is made to reduce carbon emissions) would probably, by itself,
increase temperature only about 1 degree centigrade by the
end of the century—warmer, to be sure, but probably [most
certainly!] short of doomsday. True catastrophe would require
a helping hand from water vapor. That’s exactly what most
models depict.
"But here’s the
rub: water vapor is not well understood. Models, for instance,
assume that a warmer atmosphere would hold more water vapor,
but it wouldn’t necessarily, says Lindzen. Another wild card
is the role of clouds in regulating humidity. Cumulus clouds
draw moist air from the surface and carry it skyward. Some
of the moisture falls back to the ground as rain, and what’s
left over is taken high up in the atmosphere, where it freezes
into cirrus clouds. These clouds drift hundreds of miles raining
ice particles into the lower atmosphere; these evaporate and
raise humidity. But how much? Lindzen asserts that as the
atmosphere warms, cumulus clouds will produce rain more efficiently,
thereby leaving less for humidity-causing cirrus clouds. The
result would be drier air. Rather than amplifying the greenhouse
effect of carbon dioxide, this would counteract it.
"Even if scientists
understood climate perfectly, the models would still contain
another type of error inherent in the way computers do the
calculations. In an ideal world, models would account for
everything, down to each molecule of water. In practice, compromises
are made. The Hadley Centre’s model, for instance, dices the
atmosphere into 250-kilometer squares, and then crunches equations
that describe scientists’ best approximation of the atmosphere’s
aggregate behavior. Making the squares smaller would reduce
error, but it’s expensive: shrink the squares to 125km, and
the calculation balloons 16-fold. Even so, much of what goes
on at the scale of clouds is lost.
...
"Modelers concede
both types of uncertainty but insist that their predictions
are still valid. ... The IPCC report agrees: 'Confidence in
the ability of models to project future climate has increased.'
Nonsense, says Lindzen. 'The argument that the models are
continually improving is a kind of motherhood statement that
international reports always make. But there’s no evidence
of that.'"[1]
Finally, Prof. Philip Stott
in a Wall Street Journal commentary, quotes the Third
Assessment Report of the Intergovernmental Panel on Climate
Change (IPCC) [italics added]:
"In sum,
a strategy must recognize what is possible. In climate research
and modeling, we should recognize that we are dealing with a
coupled non-linear system, and therefore that the prediction
of a specific future climate is not possible."[11]
If there is one thing that is
clear in all this, it is that scientists do not have a clear
understanding of all the important factors that drive climate
changes. Until recently, few gave any credibility to the notion
that solar variability had any real influence on climate change.
Coupled with what we've recently learned about the solar factor
and how changes in climate during the past millennium (Medieval
Warm Period & Little Ice Age) are strongly linked to changes
in solar output, the crudeness of both climate simulation models
and data driving those models provides a compelling case for
skepticism of the claims of global warming alarmists.
Lindzen,
Dr. Richard S. (MIT) in the December 14, 1997 issue of the
Boston Herald, "Forum: Let this be a warming - Kyoto
backs bad policy as good science"
Easterbrook,
Gregg, A Moment On The Earth, pp 295-296.
Ibid,
p 296.
Ibid.
Lindzen,
Dr. Richard S. (Alfred P. Sloan Professor of Meteorology,
Massachuesetts Institute of Technology) in Global Warming:
The Origin and Nature of the Alleged Scientific Consensus,
6th paragraph.
