Website: Petition Project at http://www.sitewave.net/pproject
Section: Global Warming Review
Topic: Letter from Frederick Seitz
Title: Research Review of Global Warming Evidence
Below is an eight page review of information on the subject of
"global warming," and a petition in the form of a reply card. Please
consider these materials carefully.
The United States is very close to adopting an international
agreement that would ration the use of energy and of technologies
that depend upon coal, oil, and natural gas and some other organic
compounds.
This treaty is, in our opinion, based upon flawed ideas. Research
data on climate change do not show that human use of
hydrocarbons is harmful. To the contrary, there is good evidence
that increased atmospheric carbon dioxide is environmentally
helpful.
The proposed agreement would have very negative effects upon the
technology of nations throughout the world, especially those that are
currently attempting to lift from poverty and provide opportunities
to the over 4 billion people in technologically underdeveloped
countries.
It is especially important for America to hear from its citizens who
have the training necessary to evaluate the relevant data and offer
sound advice.
We urge you to sign and return the petition card. If you would like
more cards for use by your colleagues, these will be sent.
Frederick Seitz
Past President, National Academy of Sciences, U.S.A.
President Emeritus, Rockefeller University
Website: Petition Project at http://www.sitewave.net/pproject
Section: Global Warming Review
Topic: Environmental Effects of Increased Atmospheric Carbon
Dioxide
Title: Abstract
Click here to receive this document in PDF format.
ARTHUR B. ROBINSON, SALLIE L. BALIUNAS, WILLIE
SOON, AND ZACHARY W. ROBINSON
Oregon Institute of Science and Medicine, 2251 Dick George Rd.,
Cave Junction, Oregon 97523 i...@oism.org
George C. Marshall Institute, 1730 K St., NW, Ste 905,
Washington, DC 20006 i...@marshall.org January 1998
ABSTRACT
A review of the research literature concerning the environmental
consequences of increased levels of atmospheric carbon dioxide
leads to the conclusion that increases during the 20th Century have
produced no deleterious effects upon global weather, climate, or
temperature. Increased carbon dioxide has, however, markedly
increased plant growth rates. Predictions of harmful climatic effects
due to future increases in minor greenhouse gases like CO2 are in
error and do not conform to current experimental knowledge.
Title: Summary
World leaders gathered in Kyoto, Japan, in December 1997 to
consider a world treaty restricting emissions of ''greenhouse gases,''
chiefly carbon dioxide (CO2), that are thought to cause ''global
warming'' severe increases in Earth's atmospheric and surface
temperatures, with disastrous environmental consequences.
Predictions of global warming are based on computer climate
modeling, a branch of science still in its infancy. The empirical
evidence actual measurements of Earth's temperature shows no
man-made warming trend. Indeed, over the past two decades,
when CO2 levels have been at their highest, global average
temperatures have actually cooled slightly.
To be sure, CO2 levels have increased substantially since the
Industrial Revolution, and are expected to continue doing so. It is
reasonable to believe that humans have been responsible for much
of this increase. But the effect on the environment is likely to be
benign. Greenhouse gases cause plant life, and the animal life that
depends upon it, to thrive. What mankind is doing is liberating
carbon from beneath the Earth's surface and putting it into the
atmosphere, where it is available for conversion into living
organisms.
Title: Rise In Atmospheric Carbon Dioxide
The concentration of CO2 in Earth's atmosphere has increased
during the past century, as shown in figure 1 (1).
Figure 1 Atmospheric CO2 concentrations in parts per
million by volume, ppm, at Mauna Loa, Hawaii. These
measurements agree well with those at other locations (1).
Periodic cycle is caused by seasonal variations in CO2
absorption by plants. Approximate global level of
atmospheric CO2 in 1900 and 1940 is also displayed (2).
The annual cycles in figure 1 are the result of seasonal variations in
plant use of carbon dioxide. Solid horizontal lines show the levels
that prevailed in 1900 and 1940 (2). The magnitude of this
atmospheric increase during the 1980s was about 3 gigatons of
carbon (Gt C) per year (3). Total human CO2 emissions primarily
from use of coal, oil, and natural gas and the production of cement
are currently about 5.5 GT C per year.
To put these figures in perspective, it is estimated that the
atmosphere contains 750 Gt C; the surface ocean contains 1,000
Gt C; vegetation, soils, and detritus contain 2,200 Gt C; and the
intermediate and deep oceans contain 38,000 Gt C (3). Each year,
the surface ocean and atmosphere exchange an estimated 90 Gt C;
vegetation and the atmosphere, 60 Gt C; marine biota and the
surface ocean, 50 Gt C; and the surface ocean and the intermediate
and deep oceans, 100 Gt C (3).
Figure 2 Surface temperatures in the Sargaso Sea (with time
resolution of about 50 years) ending in 1975 as determined
by isotope ratios of marine organism remains in sediment at
the bottom of the sea (7). The horizontal line is the average
temperature for this 3,000 year period. The Little Ice Age
and Medieval Climate Optimum were naturally occurring,
extended intervals of climate departures from the mean.
So great are the magnitudes of these reservoirs, the rates of
exchange between them, and the uncertainties with which these
numbers are estimated that the source of the recent rise in
atmospheric carbon dioxide has not been determined with certainty
(4). Atmospheric concentrations of CO2 are reported to have
varied widely over geological time, with peaks, according to some
estimates, some 20-fold higher than at present and lows at
approximately 18th-Century levels (5).
The current increase in carbon dioxide follows a 300-year warming
trend: Surface and atmospheric temperatures have been recovering
from an unusually cold period known as the Little Ice Age. The
observed increases are of a magnitude that can, for example, be
explained by oceans giving off gases naturally as temperatures rise.
Indeed, recent carbon dioxide rises have shown a tendency to
follow rather than lead global temperature increases (6).
There is, however, a widely believed hypothesis that the 3 Gt C per
year rise in atmospheric carbon dioxide is the result of the 5.5 Gt C
per year release of carbon dioxide from human activities. This
hypothesis is reasonable, since the magnitudes of human release and
atmospheric rise are comparable, and the atmospheric rise has
occurred contemporaneously with the increase in production of
CO2 from human activities since the Industrial Revolution.
Figure 3 Moving 11-year average of terrestrial Northern
Hemisphere peratures as deviations in ºC from the
1951-1970 mean left axis and darker line (8,9). Solar
magnetic cycle lengths right axis and lighter line (10). The
shorter the magnetic cycle length, the more active, and hence
brighter, the sun.
Title: Atmospheric And Surface Temperatures
In any case, what effect is the rise in CO2 having upon the global
environment? The temperature of the Earth varies naturally over a
wide range. Figure 2 summarizes, for example, surface
temperatures in the Sargaso Sea (a region of the Atlantic Ocean)
during the past 3,000 years (7). Sea surface temperatures at this
location have varied over a range of about 3.6 degrees Celsius (ºC)
during the past 3,000 years. Trends in these data correspond to
similar features that are known from the historical record.
Figure 4 Annual mean surface temperatures in the contiguous
United States between 1895 and 1997, as compiled by the
National Climate Data Center (12). Horizontal line is the
103-year mean. The trend line for this 103-year period has a
slope of 0.022 ºC per decade or 0.22 ºC per century. The
trend line for 1940 to 1997 has a slope of 0.008 ºC per
decade or 0.08 ºC per century.
For example, about 300 years ago, the Earth was experiencing the
''Little Ice Age.'' It had descended into this relatively cool period
from a warm interval about 1,000 years ago known as the
''Medieval Climate Optimum.'' During the Medieval Climate
Optimum, temperatures were warm enough to allow the
colonization of Greenland. These colonies were abandoned after
the onset of colder temperatures. For the past 300 years, global
temperatures have been gradually recovering (11). As shown in
figure 2, they are still a little below the average for the past 3,000
years. The human historical record does not report ''global
warming'' catastrophes, even though temperatures have been far
higher during much of the last three millennia.
What causes such variations in Earth's temperature? The answer
may be fluctuations in solar activity. Figure 3 shows the period of
warming from the Little Ice Age in greater detail by means of an
11-year moving average of surface temperatures in the Northern
Hemisphere (10). Also shown are solar magnetic cycle lengths for
the same period. It is clear that even relatively short,
half-century-long fluctuations in temperature correlate well with
variations in solar activity. When the cycles are short, the sun is
more active, hence brighter; and the Earth is warmer. These
variations in the activity of the sun are typical of stars close in mass
and age to the sun (13).
Figure 4 shows the annual average temperatures of the United
States as compiled by the National Climate Data Center (12). The
most recent upward temperature fluctuation from the Little Ice Age
(between 1900 and 1940), as shown in the
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