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

Greenland perished.

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.