Why CO2 is implicated in global warming?
They said CO2 insulates heat of the earth, how? and why greenhouse gases specifically insulates? give their anatomies.
specific heat capacity of CO2 is 0.8 KJ/KgK at 300K while oxygen is 0.9, this difference is too little to produce global warming.
Want to hear more controversials on global warming from me before you give out all your reasons why man-accused global warming?
Answer:
You are right about emitting infrared back into space. The CO2 can't control the direction with which it radiates this absorbed heat. As CO2 atoms become more dispersed at higher altitudes, then more heat is radiated upward. At the lower altitudes, you might expect the inverse.
But that is academic when you consider that water vapor is present in far greater concentration in the atmosphere, has a specific heat capacity of more than double CO2, at 1.9 KJ/KgK at 300K, and absorbs infrared light at pretty much the same portions of the spectra as CO2.
And let's not EVEN get into clouds with water droplets that have five times the specific heat capacity of CO2, and a surface that not only absorbs and re-emits IR, but also partially reflects it.
The data you will see coming from the global warming crowd is the product of laboratory and computer simulations which, despite claims to the contrary, have not been able to effectively simulate the thermodynamics of clouds.
There is little empirical evidence to implicate CO2 in global warming. And I'm being generous with the use of the word "little"...
The specific heat of CO2 has little or nothing to do with the question. The effect of CO2 is it's ability to absorb long wavelength infra-red radiation first, directly from the Sun, and second, from the infra-red radiation emitted by the ground and sea at ordinary surface temperatures. If you increase the concentration of CO2 in the air, you increase absorption of infra-red by CO2. This heats the CO2 which transmits heat to the surrounding gases by conduction.
Oxygen, making up 20.93% of the atmosphere, and nitrogen, making up 78.1% and argon, making up most of the rest of dry air are poor absorbers of infra-red.
Water is a good absorber. However the water content of the atmosphere is outside human control. On the other hand, CO2 has risen from about 280ppm by volume in the 19th century to 300ppm in the mid 1960s, 320ppm in the mid-late 1970s, 345ppm in the 1980s and now about 380ppm. This is a very large increase in barely more than a human lifetime.
Examination of the isotopic content of the CO2 reveals that much has been produced by burning coal and oil. Thus it is apparent that the increase in CO2 content is under human control.
During the period 1966 to 1990, coal production in Queensland, Australia rose from a few million tonnes per year to well over 86 million tonnes per year and has increased since. In other mining areas production has shown similar increases. Electricity production is up all round the world and so is motor vehicle ownership and use.
Increase in global temperatures created by accumulation of CO2 was predicted in 1896 by the physical chemist Svante Arrhenius. After some small scale scientific controversy which lasted until about 1914 the prediction was mostly forgotten until the 1960s, but by 1972 or earlier another chemist began to publish on the matter. I became aware of it in the later 1970s. In the 1980s regular articles began to appear in popular scientific press like Scientific American and New Scientist and also received attention in business magazines.
Basically, the light radiation goes throw them as they enter Earth's atmosphere. They are absorbed by Earth's surface and then reemitted as infrared radiation (another wave length). These wave lengths are absorbed by the GHG's. The GHG's (includong CO2) then re-radiates roughly 50% of this radiation to the Earth's surface heating it a second time. Hope this helps.
greenhouse gases are those that absorb longwave infrared radiation...longwave infrared radiation is emitted by the Earth's surface and captured in the atmosphere hence the analagy with a greenhouse
Why do only certain gases absorb infrared radiation? Well in the simplest of explanations, for reasons unknown infrared radiation is absorbed only if a molecule contains more than two atoms, or if it contains just two, then the atoms are of different elements...hence why oxygen, argon and nitrogen are not greenhouse gases
when H2O and CO2 absorb infrared radiation, their bonds act like springs and vibrate more vigorously and in the case of H20, the molecule also rotates faster.
I hope that answered your question
edit: to respond to your additional statement
no, that is why the atmosphere is analagous to the panes of glass in a greenhouse, some radiation is reflected back into space but the majority of it is absorbed, hence the heating effect...put it another way, if it were not for this heating effect, temperatures would drop drastically, so we rely on these "greenhouse" gases to sustain life...and that is why the concentration of CO2 is an important factor.
Yes water is an important contributor to the greenhouse effect, actually by 60%..that fact is not being disputed.HOWEVER, the amount of infrared radiation being absorbed by the atmosphere largely depends on how many water and carbon dioxide molecules are present, obviously, the more present the greater proportion of radiation absorbed. The less there is, then more of this radiation would escape back into space and the less absorbed by the Earth's surface due to the reduction of radiation being emitted by the atmosphere.
Conversely, the more carbon dioxide and water molecules present in the atmosphere, then obviously it stands to reason that greenhouse effect will be far greater leading to rising surface temperatures.
"If the are good at absorbing infrared radiation, then they are good at emitting it back into space."
Here's why this is wrong. Sunlight strikes the Earth and infrared radiation (heat) is created. Some stays down, while some heads back out into space. Some of that infrared radiation heading out is absorbed by CO2. The CO2 does emit it again, but _in all directions_ including back down. A fraction does go back up, but it's then intercepted by other CO2, and reradiated in all directions once again.
In effect CO2 acts something like a mirror, reflecting heat back down.
the heat in co2 produces heat and that brings global warming
If you know so much why are you so wrong?
http://www.fightglobalwarming.com/page.c...
http://www.eia.doe.gov/oiaf/1605/ggccebr...
CO2 does not cause global warming. The sun is the reason for global warming. CO2 does increase as temperature increases but the correlation Al Gore makes is backwards. CO2 increases after the temps go up. CO2 increases because of the temp changes, not the other way around. Now study of sun spot activity shows that increased sun spot activity has a direct effect on the earths warming. What's dangerous about the global warming debate is that it is governed but money. Scientists and researchers who are more likely to get grants by keeping global warming a man made problem. Actually it is not a problem at all, it is just the natural cycle of the earth, there have been hotter ages than this one were in now. In the seventies the fear was global cooling. We should be good stewards of the world we live in, but we have to be sure we don't hurt people in developing nations by restricting there sources of power to only "green" sources that are too expensive and not very reliable. That is the real danger here, that we let humans suffer because of the myth of human caused global warming. Watch the video in the link.
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