Welcome to the Panic Free Zone!

Preface

What do you believe about man-made CO₂ and the global climate?

Many people have been led to believe:

that the average global temperature is about to increase radically and abruptly due to carbon dioxide (CO₂) that is being released into the atmosphere by human activity, such as heating, transportation, industry, et cetera, and,
that this will be bad for human civilization, and,
that it is necessary to adjust CO₂ levels, and,
that it is possible to adjust CO₂ levels within the time frame under consideration, and,
that all governments, which are already heavily in debt due to previous unwise spending, should spend however much it takes in order to reduce atmospheric CO₂ to the level of some arbitrary date in the past.

For simplicity and brevity we will refer to the more radically minded people among us as the "Panicers".

On the other hand, many people think that the science behind these beliefs does not meet the high standards that we expect from scientists in other fields. These folks think:

that modern CO₂ levels can not cause temperatures to rise as much as the "Panicers'" computer models are predicting, and,
that a temperature increase, if one does occur, is not necessarily a bad thing, and,
that adjusting CO₂ levels is not necessary, and,
that it is not possible to adjust CO₂ levels at a reasonable cost within any near term time frame, and,
that governments, especially those which are already heavily in debt due to previous unwise spending, should first spend a little more money on research before commiting to reduce atmospheric CO₂ to the level of some arbitrary date in the past, and,
that it is not ethical to pay people in third world countries not to burn hydrocarbons (i.e. - pay them not to develop their economy) so that the Al Gores of the world can live in gas guzzling mega-homes while people in developing countries continue to live in shacks (sort of like a fat many paying a starving man to go on a diet for him). PS: In case you did not recognize it, this last reference is to the Kyoto Accord's wacky carbon credit scheme/scam.

For simplicity and brevity we will refer to the more rationally minded people among us as the "Thinkers".

A Short Summary of the Debate to Date

Is there some degree of agreement on global climate change?

In a word - YES.

We all know that the earth's climate has gone through many changes over millions of years. Thanks to ice core samples from Antarctica we have a pretty clear picture of the climactic cycles that the earth has gone through over the last 800,000 years. Here is a summary of the points that most people agree on:

Every 120,000 years (approximately) the earth's average temperature swings between a minimum of 9 or 10 degrees below modern temperatures and a maximum of a few degrees cooler or warmer than modern temperatures. The warming phase of these cycles is very rapid - it takes only about 10,000 years for average temperatures to swing from the minimum to the maximum. The cooling phase - from maximum to minimum - takes much longer - on the order of 110,000 years.
The precise details of these cycles is not completely understood, but it is widely accepted that changes in the earth's orbit trigger these cycles. If you compare the variation in the eccentricity of earth's orbit to the variation earth's average temperature you will immediately see a strong correlation. Both these cycles take about 120,000 years. There are also shorter temperature cycles that occur on the order of 20 and 40 thousand years which correlate well with the cycles in the obliquity (tilt) of earth's axis and precession of the earth's axis.
If you are interested enough in this subject to have found this page you will also know that the CO₂ levels in the atmosphere follow the 120,000 year temperature cycles very closely, with the CO₂ changes lagging behind the temperature changes. It is also widely accepted that these changes in atmospheric CO₂ are the result of changes in the ocean temperatures. Cold water can dissolve more CO₂ than warm water, thus as the oceans warm up they release CO₂ into the air.

Where do people disagree on global climate change?

The earth's atmosphere protects us from cosmic rays and ultraviolet rays, and it buffers us from violent temperature swings. Several components of the earth's atmosphere are known to play a role in regulating the earth's temperature, although the precise mechanism by which this regulation takes place is not well understood. Water vapour is the primary factor in global temperature regulation, with CO₂ being the next most important factor, and with CH₄ also cplaying a role in this protective blanket.

The "Panicers" believe that CO₂ plays a huge role in heating up the troposhere and thus in increasing the earth's average atmospheric temperature. In other words, they believe that a vicious circle is in play whereby orbital changes increase earth's average temperature, and then:

Increases in earth's average temperature cause atmospheric CO₂ levels to increase, and then
atmospheric CO₂ increases cause earth's average temperature to increase, and then
increases in earth's average temperature cause atmospheric CO₂ levels to increase, and then
atmospheric CO₂ increases cause earth's average temperature to increase, and then...

The "Thinkers" believe that CO₂ plays a modest role in heating up the troposhere and thus in increasing the earth's average temperature. In other words, they do not believe that a vicious circle is in play, but rather, something along these lines:

Orbital changes increase earth's average atmospheric temperature, which increases the temperature of the earth's oceans.

As the oceans warm up they cannot hold as much CO₂ in solution, so CO₂ is gradually released into the atmosphere.

When the ocean temperatures are increasing the CO₂ release lags temperature increases by 800 to 1,000 years. If you check the 160 kyr graph you will notice that this 800 year lag is difficult to see due to the fact that both temperature and CO₂ are rising quickly (well, "quickly" in geologic terms).

When the ocean temperatures are decreasing the CO₂ dissolution back into the oceans lags temperature decreases by several thousand years. If you check the 160 kyr graph again you will notice that this lag is easy to see. Why is there a longer CO₂ when temperature is decreasing than when it is increasing? Here's why:

When the oceans warm the CO₂ is released from the whole volume of the warmer water.
When the oceans cool the CO₂ is dissolved only at the surface of the cooler water. Since the surface area is smaller than the volume it is to be expected that CO₂ levels will decrease when temperatures drop slower than CO₂ increase when temperatures rise.

So why do the "Panicers" believe in the "vicious circle" theory of abprupt temperature increase? Well, that is a story rooted in money and politics rather than science, and we'll tell that story later. For now we will explain why "Thinkers" do not believe in the "vicious circle" theory of abprupt temperature increase.

Come back soon to learn more about the true story of how CO₂ levels impact temperatures.