Climate Change not due to Greenhouse Gases:
Controlling Global Warming by Albedo Management

David Noel
Ben Franklin Centre for Theoretical Research
PO Box 27, Subiaco, WA 6008, Australia.


But Scientists, who ought to know,
Assure us that they must be so....
Oh! let us never, never doubt
What nobody is sure about!

From The Microbe, by Hillaire Belloc

Concern with global warming and extreme climatic events is understandable, but we may be living in a state of delusion unless we look at some basic calculations on this matter.

By far the greatest source of the energy that Earth receives is energy from the Sun. Each year we receive about 5600 Q units of energy, where Q is a large unit equal to about 10 to the 21 joules.

Quite a lot of this energy is immediately reflected off. For our planet, this reflection factor or albedo is about 37%. The precise value at any one time depends on the reflectivity of objects on the sunward side, but clouds have the highest reflectivity of common objects, while snow and ice are also important.

Man's total energy production for the whole planet is of the order of 0.34 Q per year. In other words, what we produce is much less than one ten-thousandth of what we get from the sun. This has some fundamental implications.

First, global warming is probably entirely due to some very small variations in the solar energy taken up by the Earth, and in particular to tiny variations in albedo.

Second, current unwanted effects of global warming or extreme climatic events could be controlled by conscious albedo management, that is by adjusting the reflectivity of the Earth's surface features.

Third, such adjustments would be effective, whatever the underlying causes of global warming.

Global warming is usually attributed to established recent rises in so-called 'greenhouse gases', in particular, carbon dioxide. Surprisingly, when examined rigorously, this idea does not have much logic or evidence to support it.

It is true that a correlation has been established between varying carbon-dioxide levels and average global temperatures, but this does not prove that more carbon dioxide causes warming, any more than it proves that high temperatures cause more carbon dioxide release.

Nor have the suggested mechanisms by which these gases bring about warming received universal acceptance, and in any case such warming looks insignificant in the overall picture.

There is an alternative explanation which does have this logical and evidential basis. That is, that increases in temperatures are due to forest clearances, which have occurred since agriculture began some 15,000 years ago, and greatly accelerated in modern times.

The mechanisms are obvious. Soil beneath a forest cover is not warmed as are exposed soils in open country, because the energy is trapped and converted into biomass or reflected before it reaches the surface.

In addition, cloud cover over forest and jungle areas is always more obvious than that over desert or poorly-vegetated areas. As the Earth's surface has been progressively cleared of tree cover, its level of cloud cover has fallen, its average albedo has reduced, and its acceptance of solar energy has risen.

This explanation fits in better with observed climatic events than any mechanism based on 'greenhouse gases'. Daily temperature variations under an overcast sky are always much smaller than under a clear sky.

Forest clearance has a double effect on carbon dioxide levels. Not only is the carbon locked up in the forests released into the atmosphere, but also the carbon sink represented by the trees is removed from the balance.

Data sources such as that used in Google Earth have recorded degree of cloud cover over the planet in past years. It might be instructive to correlate such cloud cover data with climatic events during this period.

Cloudiness might be increased in the short term by direct injection of moisture and nuclei at appropriate atmospheric levels, and in the longer term by restoring tree cover. Rows of solar towers should create a 'thermal mountain range' effect, leading to cloud formation, and at the same time generate large amounts of renewable, non-polluting energy.

Artificial enhancement of local reflectivity could be achieved by sheets of reflective materials on the ground, or suspended in the air from conventional or vacuum balloons. These sheets could incorporate solar cells, another major source of renewable energy.

These ideas barely scratch the surface of what could be a major field of advance in understanding and existing in productive symbiosis with our planet's natural processes.

If this reasoning is correct, there is a sobering thought for our efforts to manage climate change. It may be that all the expense and thought put into reducing 'greenhouse gases' may have been misdirected, although the global analysis and cooperation undertaken could be a valuable basis for tackling the problem through forest restoration mechanisms.

2006 February 8

Details of calculations and data sources are at

Some relevant links:
The Vacuum Balloon, a New approach to Building 'Skyhooks' with a great range of Uses.
Thoughts about Solar Towers, Promising new Energy Source from the Environment.

Go to BCW Home Page

Circulated generally 2006 Feb 8
This version on Web 2006 Mar 4