Greenhouse Theory Disproved a Century Ago

Since 07-16-09

Lowering CO2 is insanity. It is the breath of life for our food crops and all vegetation in the world. Reduction of CO2 in the air will reek havoc on our food crops.

February 4, 2009
Mathematician’s View
http://neighbors.denverpost.com/blog.php/2009/02/04/greenhouse-theory-disproved-a-century-ago/

Posted by reasonmclucus

The claim that carbon dioxide (CO2) can increase air temperatures by “trapping” infrared radiation (IR) ignores the fact that in 1909 physicist R.W. Wood disproved the popular 19th Century thesis that greenhouses stayed warm by trapping IR. Unfortunately, many people who claim to be scientists are unaware of Wood’s experiment which was originally published in the Philosophical magazine , 1909, vol 17, p319-320. Wood was an expert on IR. His accomplishments included inventing both IR and UV (ultraviolet) photography.

Wood constructed two identical small greenhouses. The description implies the type of structure a gardener would refer to as a “coldframe” rather than a building a person could walk into.

He lined the interior with black cardboard which would absorb radiation and convert it to heat which would heat the air through conduction. The cardboard would also produce radiation. He covered one greenhouse with a sheet of transparent rock salt and the other with a sheet of glass. The glass would block IR and the rock salt would allow it to pass.

During the first run of the experiment the rock salt greenhouse heated faster due to IR from the sun entering it but not the glass greenhouse. He then set up another pane of glass to filter the IR from the sun before the light reached the greenhouses.

The result from this run was that the greenhouses both heated to about 50 C with less than a degree difference between the two. Wood didn’t indicate which was warmer or whether there was any difference in the thermal conductivity between the glass sheet and the rock salt. A slight difference in the amount of heat transfered through the sheets by conduction could explain such a minor difference in temperature. The two sheets probably didn’t conduct heat at the same rate.

The experiment conclusively demonstrates that greenhouses heat up and stay warm by confining heated air rather than by trapping IR. If trapping IR in an enclosed space doesn’t cause higher air temperature than CO2 in the atmosphere cannot cause higher air temperatures.

The heated air in the greenhouses couldn’t rise higher than the sheets that covered the tops of the greenhouses. Heated air outside is free to rise allowing colder air to fall to the ground.
Atmospheric CO2 is even less likely to function as a barrier to IR or reflect it back to reheat the ground or water than the sheet of glass in Wood’s greenhouse.

The blackened cardboard in Wood’s greenhouses was a very good radiator of IR as is typical of black substances. The water that covers 70% of earth’s surface is a very poor radiator and produces only limited amounts of IR as is typical of transparent substances. Water releases heat through evaporation rather than radiation.

The glass sheet provided a solid barrier to IR. Atmospheric CO2 is widely dispersed comprising less than 400 parts per million in the atmosphere. Trapping IR with CO2 would be like trying to confine mice with a chain link fence.

Glass reflects a wider spectrum of IR than interacts with CO2. The glass sheets reflected IR back toward the floor of the greenhouse. CO2 doesn’t reflect IR.

At the time of Wood’s experiment, it was believed that CO2 and other gas molecules became hotter after absorbing IR.

Four years later Niels Bohr reported his discovery that the absorption of specific wavelengths of light didn’t cause gas atoms/molecules to become hotter. Instead, the absorption of specific wavelengths of light caused the electrons in an atom/molecule to move to a higher energy state. After absorption of light of a specific wavelength an atom couldn’t absorb additional radiation of that wavelength without first emitting light of that wavelength. (Philosophical Magazine Series 6, Volume 26 July 1913, p. 1-25)

Unlike the glass which reflects IR back where it comes from, CO2 molecules emit IR up and sideways as well as down. In the time interval between absorbing and reemitting radiation, CO2 molecules allow IR to pass them by. Glass continuously reflects IR.

Those who claim that CO2 molecules in the atmosphere can cause heating by trapping IR have yet to provide any empirical scientific evidence to prove such a physical process exists. The experiment by R.W. Wood demonstrates that even a highly reflective covering cannot cause heating by trapping IR in a confined space. There is no way CO2, which at best only affects a small portion of the IR produced by earth’s surface, can heat the atmosphere by trapping IR.

Contrary to the lie repeated in news stories about climate, science doesn’t say that CO2 is causing higher temperatures by trapping IR. Empirical science indicates that no such process exists in this physical universe.

Use of CO2 in Greenhouses

http://www.advancegreenhouses.com/use_of_co2_in_a_greenhouse.htm

Carbon dioxide is one of the essential ingredients in green plant growth and is a primary environmental factor in greenhouses. CO2 enrichment at 2, 3 or four times natural concentration will cause plants to grow faster and improve plant will quality.

Modern growers are becoming increasingly aware of the value of CO2. Particularly now that most greenhouses are purposely shutting out CO2 [air] to conserve energy.

Carbon dioxide is an odorless gas and a minor constituent in the air we breathe. It comprises only .03% [ 300 parts per million, or PPM] of the atmosphere, but is virtually important to all life on this planet!

Plants are made up of about 90% carbon and water with other elements like nitrogen calcium, magnesium, potassium, phosphorus and trace elements making up only a small percentage. Almost all the carbon in plants comes from this minor 300 ppm of carbon dioxide in the air.

The process called photosynthesis is that plants take in CO2 through pores called stoma, in their leaves during the daylight hours. They give off oxygen at the same time. Without this oxygen animal and human life would not be possible.

The reason you will get more rapid and efficient growth and better plant quality with a higher CO2 level is because plants must absorb CO2 in combination with water, soil nutrients and sunlight which produces sugars which are vital for growth. If any of these elements are missing or low, plant growth will be retarded. When CO2 is increased to over 1000 ppm it results in higher production and plant quality.

The best time to add CO2 is from dawn to dusk. CO2 ranges from 400 to 500 ppm during the night due to plant respiration. Right after sunrise a level will drop to about 300 ppm. After three to four hours of early sun light it will drop to 100 to 250 ppm at which time growth will stop. If you add CO2 during the winter months when ventilators are closed and CO2 concentrations are low, you will get increased yield and bloom which normally happens during the spring and summer.

This is a formula which can be used to figure what amount of CO2 must be added to reach 1000 ppm.
9 ft.³ of CO2 per hour per 1000 ft.² yields 1000 ppm

When there is sunlight and vents are closed you should be adding CO2 continuously to your greenhouse. If the vents are open because of heat you should continue to add CO2 for two additional hours.