Editor's Note: We are posting this article from our July 1959 issue to offer an historical perspective on some of the issues being discussed at the United Nations Framework Climate Change Conference in Poznan, Poland, which began December 1 and runs through December 12.
The theories that explain worldwide climate change are almost as varied as the weather. The more familiar ones attribute changes of climate to Olympian forces that range from geological upheavals and dust-belching volcanoes to long-term variations in the radiation of the sun and eccentricities in the orbit of the earth. Only the so-called carbon dioxide theory takes account of the possibility that human activities may have some effect on climate. This theory suggests that in the present century man is unwittingly raising the temperature of the earth by his industrial and agricultural activities.
Even the carbon dioxide theory is not new; the basic idea was first precisely stated in 1861 by the noted British physicist John Tyndall. He attributed climatic temperature-changes to variations in the amount of carbon dioxide in the atmosphere. According to the theory, carbon dioxide controls temperature because the carbon dioxide molecules in the air absorb infrared radiation. The carbon dioxide and other gases in the atmosphere are virtually transparent to the visible radiation that delivers the sun's energy to the earth. But the earth in turn reradiates much of the energy in the invisible infrared region of the spectrum. This radiation is most intense at wavelengths very close to the principal absorption band (13 to 17 microns) of the carbon dioxide spectrum. When the carbon dioxide concentration is sufficiently high, even its weaker absorption bands become effective, and a greater amount of infrared radiation is absorbed [see chart on page 42]. Because the carbon dioxide blanket prevents its escape into space, the trapped radiation warms up the atmosphere.
A familiar instance of this "greenhouse" effect is the heating-up of a closed automobile when it stands for a while in the summer sun. Like the atmosphere, the car's windows are transparent to the sun's visible radiation, which warms the upholstery and metal inside the car; these materials in turn re-emit some of their heat as infrared radiation. Glass, like carbon dioxide, absorbs some of this radiation and thus traps the heat, and the temperature inside the car rises.
Water vapor and ozone, as well as carbon dioxide, have this effect because they too absorb energy in the infrared region. But the climatic effects due to carbon dioxide are almost entirely independent of the amount of these other two gases. For the most part their absorption bands occur in different regions of the spectrum. In addition, nearly all water vapor remains close to the ground, while carbon dioxide diffuses more evenly through the atmosphere. Thus throughout most of the atmosphere carbon dioxide is the main factor determining changes in the radiation flux.
The 2.3 X 1012 (2,300 billion) tons of carbon dioxide in the earth's present atmosphere constitute some .03 per cent of its total mass. The quantity of carbon dioxide in the atmosphere is determined by the amounts supplied and withdrawn from three other great reservoirs: oceans, rocks and living organisms. The oceans contain some 1.3 X 1014 tons of carbon dioxide—about 50 times as much as the air. Some of the gas is dissolved in the water, but most of it is present in carbonate compounds. The oceans exchange about 200 billion tons of carbon dioxide with the atmosphere each year. When the equilibrium is disturbed, the oceans may engulf or disgorge billions of additional tons of carbon dioxide. This puts a damper on the fluctuations in the carbon dioxide content of the atmosphere: when the atmospheric concentration rises, the oceans tend to absorb much of the excess; when it fails, the oceanic reservoir replenishes it.
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9 Comments
Add CommentOh god, get ready for a bombardment of proactive naysayers.
Reply | Report Abuse | Link to thisLets see how many ways they can shoot down the statistical data yet again presented to them by unbiased minds.
That was a pretty cool article. Not only did it give us a unique look backward it gave us a fresh look forward; and it was enjoyable reading too. I was twelve years old when that was written. The streets of my home town were dusty and just about every vehicle and smoke stack was a choker. Those things a much improved now, none the less global co2 volume increases. In fifty years this scenario may repeat its self and a reader will write things are better now but co2 volumes continue to increase.
Reply | Report Abuse | Link to thisIt is good that mankind works to clean up the environment because it makes our earth a more enjoyable place to live regardless of whether we can put off the next ice age or not.
Great summary on the subject! .A good conclusion from it may be trying to reduce the amount of fuel spent on transport by bringing down the size of cars, and that of housing and industry by using isolation and more efficient heating and cooling systems. Fusion energy is on its way and the future may be not so bad. By the way: how about the decrease in gases solubility in water when sea temperature raises? Regards
Reply | Report Abuse | Link to this"Science progresses, funeral by funeral." _ Max Planck
Reply | Report Abuse | Link to thisPlease no more CO2. Before the time CO2 really does become a problem mankind will have switched to something else, hopefully fusion. Not to save the planet which in the words of George Carlin "ISN'T GOING ANYWHERE", but because we really need the energy - hundreds and thousands of times more than we are currently using. I hope when this global warming hoax is finally totally exposed and Al Gore receives his true title of CON MAN OF THE MILLENIUM that your readers remember how willingly Scientific American promoted this HOAX. Your publication doesn't have the journalistic integrity of the National Enquirer.
Reply | Report Abuse | Link to thisCO2 can't be a green house gas on earth because it absorbs infrared radiation at wavelengths that are not radiated by the earths surface. In the article it says CO2 absorbs infrared radiation in the range 13-17 microns - this corresponds to a surface temperature of about -100 celcius to -73 celcius - there is nowhere that cold on earth. Most of the earths surface is at about 17 celcius - this radiates at about 10.5 microns, CO2 is transparent to infrared radiation at that wave length.
Reply | Report Abuse | Link to thisScience doesn't change, politics changes science. It's refreshing to see that back in 1959, studies involving CO2 and temperature were not biased by current global warming alarmists.
Reply | Report Abuse | Link to thisLet's face it, the Earth are far more supreme an one step ahead of man. Let's focus on man's detrimental impact on the environment and not global warming.
From the Wiki link about John Tyndall:
Reply | Report Abuse | Link to this"He was the first to correctly measure the infrared absorptive powers of the gases nitrogen, oxygen, water vapour, carbon dioxide, ozone, methane, etc.
He concluded that water vapour is the strongest absorber of radiant heat in the atmosphere and is the principal gas controlling air temperature.
Absorption by the bulk of the other gases is negligible.
Prior to Tyndall it was widely surmised that the Earth's atmosphere has a Greenhouse Effect, but he was first to prove it.
The proof was that water vapor strongly absorbed infrared radiation."
Now - how are they going to tax water vapor?
First, John Tyndall stated that water vapor was the main gas blocking photons from escaping into space. CO2 was in the "bulk of the other gases" with negligible absorption. Thus, CO2 has a negligible effect on global warming.
Reply | Report Abuse | Link to thisSecond, notice that CO2 blocks all 15-micron photons. This means that more CO2 cannot block more photons since they are all blocked already.
Third, we should not forget that photons in sunlight at 15-microns are also blocked, thus cooling the Earth's surface in the daytime.