"VITAL ARTICLES ON SCIENCE/CREATION"
No. 204 THE CHRISTIAN AND THE GREENHOUSE EFFECT
by Larry Vardiman*
The greenhouse effect has recently become a major topic of
conversation and study in both scientific and political circles.
The explanation of how radiation is trapped by the gases in the
atmosphere and released only after the temperature of the
atmosphere warms sufficiently has become commonplace on talk shows
and in science lectures. An increasing concentration of carbon
dioxide has been identified as causing the greenhouse effect to
become more pronounced.
How should a Christian respond to environmental issues such
as this? Are the alarmist statements coming from some
environmental groups predicting worldwide catastrophe legitimate?
Has the greenhouse effect really become a problem because of
careless deeds by mankind, and should we attempt to reduce the
release of carbon dioxide by government regulation?
Carbon Dioxide Change
In 1958, observations of carbon dioxide concentration in the
atmosphere were begun at an observatory on Mauna Loa, Hawaii.
This site was selected to be representative of the global average
conditions near the surface of the earth. Figure 1 shows the
change of carbon dioxide concentration since 1958, from Ahrens',
and the estimated values before observations began and into the
next century. The general trend shows an overall accelerating
increase in concentration. If no other global variable changes,
the concentration is expected to double from the current 350 parts
per million within a century.
Global Temperature Change
Throughout much of the earth's history, the global climate was
probably between eight and ten degrees centigrade warmer than it
is today. This is true whether the geologic ages were long or
short. From a creationist perspective, the ice ages occurred
following the Flood, but may not have been necessarily associated with
extremely cold average global temperatures. Oard2 has presented a
model which shows that the ice sheets may have been a result of
warm oceans and cold continents, following the Flood.
As recently as 1000 years ago, the Northern Hemisphere was
relatively warm and dry. During this time, vineyards flourished,
and wine was produced in England, indicating warm, dry summers,
and the absence of cold springs. It was during this tranquil
period of several hundred years that the Vikings colonized Iceland
and Greenland. In the 13th and 14th centuries, Europe experienced
extreme weather variations, which caused cold winters, hot
summers, great floods, and great droughts.
In the 15th century the climate moderated, but in the 16th
century the average temperature began to cool for the next 300
years, resulting in what has been called the "Little Ice Age."
During this time, alpine glaciers increased in size and advanced
down river canyons. Winters were long and severe; summers short
and wet. The vineyards in England vanished, and farming became
impossible in the more northerly latitudes. Cut off from the rest
of the world by an advancing ice pack, the Viking colony in
Figure 2 shows the average annual temperature of the surface
air over the Northern Hemisphere from 1880 to 1985, updated from
Bergmans. In the late 1800s, the average temperature in the
Northern Hemisphere began to rise. From about 1900 until 1940,
the average temperature of the lower atmosphere rose about 0.3
degrees centigrade, followed by a slight cooling trend, until
1970. During the 1970s and into the 1980s, the average yearly
temperature again showed an overall warming trend. The five-year
period of 1980 through 1984 was the warmest on record, although
the period from 1984 to 1990 has been cooler. The average
temperature has warmed by about one degree centigrade, from the
low, in 1884, to its extreme high, in 1984.
Model Predictions and Limitations
Computer models of the atmosphere, called General Circulation
Models (GCMs), have been developed at the National Center for
Atmospheric Research and other research centers, to simulate the
climate and weather patterns of the earth. These models require
tremendous amounts of computer memory and time, to simulate even
crudely what occurs in our atmosphere.
Computer modelers are now attempting to introduce changes in
the basic parameters, such as the carbon dioxide concentration,
and are observing the differences which result. Some of the
initial findings indicate that a doubling in carbon dioxide
concentration will result in approximately five degrees centigrade
global warming, which, in turn, produces major changes in
circulation patterns and precipitation. Sea level is expected to
rise by as much as 300 feet, due to the melting of the polar caps.
Before too much reliance can be placed on these model
predictions, however, more attention needs to be placed on the
accuracy and precision of the models. Several major problems must
be solved: First, a change of one degree centigrade is near the
precision of temperature measurements. Although average global
temperatures are sometimes quoted to hundredths of a degree, the
precision of the dry-bulb thermometer, used at almost all weather
stations around the world, is 0.5 degree centigrade. Second, the
precision of the model in terms of grid size and boundary
conditions is limited because of computer constraints. And,
finally, several physical processes have been ignored because they
are considered of secondary importance, or they are not capable of
accurate treatment at this time.
An example of a process which has not been adequately
included is cloudiness. Cloud cover is an extremely important
process in the atmosphere because it so strongly determines the
degree of transmission and reflection of solar radiation.
Although considered to be one of the most critical unsolved
problems in atmospheric science, it is not treated well, because
its parameterization is so inaccurate. Yet, if it were to be
seriously considered, the estimates of global warming would most
likely be reduced because of the feedback process between warming
and cloud cover. The more the warming, the more the cloud cover; the
more the cloud cover, the less the solar transmission, and, probably,
the less the warming. The real atmosphere is a very stable system, and
probably will not produce the major changes predicted by the GCMS,
which do not include these cloud cover effects.
It is not yet clear whether the increase in carbon dioxide in the
atmosphere is necessarily connected to the observed temperature
changes or will result in the dire predictions of further
temperature increase and changes in precipitation patterns.
Because of this uncertainty, it is probably too early to begin
developing public policy on carbon dioxide emissions related to
temperature increases. However, because of evidence that other
pollutants produce harmful effects, and the potential that carbon
dioxide may also be a problem, it may be time that we reconsider
our personal role as stewards of this earth.
We should not adopt the secular view that "Mother Earth" must
be protected at all costs. This is to fall into the error of
pantheism, which teaches that the earth, the sun, and the stars
are all there is. Such a view is wrong, because it attributes
deity to the earth. We need to understand the mandate to "have
dominion ... over all the earth" that God has given us in Genesis
1:26. Man is responsible to use the earth to sustain himself, and
to occupy until the owner returns, as described in Matthew
25:14-30. God expects us to use the earth, and to keep it in good
repair, much as a landowner would expect his tenants to keep up
his farm while he was away.
Such a balanced view of responsible use will necessitate
considered adjustments in personal life styles. As Christians, we
are already called to live a simple life committed to the good of
others. An extravagant life, wasteful of resources and heedless
of others, is inconsistent with the Biblical model of a Christian.
Each Christian must listen to the leading of the Holy Spirit in
this issue, and adopt a lifestyle consistent with that leading.
If, after further study we find a clear link between carbon
dioxide emission and global warming, we may need to carefully
consider public policy in this area.
1, Donald C. Ahrens, 1988: Meteorology Today, 3rd Ed., West
Publishing Company, San Francisco, 582 pp.
2. Michael J. Oard, 1986: An Ice Age Within the Biblical Time
Frame, Proceedings of the First International Conference on
Creationism, Vol. II, Technical Symposium Sessions and
Additional Topics, Pittsburgh, Pennsylvania, pp. 157-166.
3. K. H. Bergman, 1983: International Journal of Enuiront-nental
Studies, Vol. 20, p. 93.