Visible light passes through the air which is transparent to visible light, hits the ground and is absorbed. That transfers the light energy into heat energy of the ground, making it warmer. The warmer the ground gets the more infrared light it emits. REALLY hot things are red hot but things that are only warm are "infrared hot". CO2 gas is not transparent to infrared light so more CO2 in the air means more infrared light is absorbed by molecules in the air and less infrared light passes through the air and back out to space, taking it's heat energy with it. The Earth as a whole must be a bit warmer to produce even more infrared light get the same amount of heat sent back to space so it again equals in incoming heat from visible light, which makes the planet warmer.
Molecules of greenhouse gases vibrate when hit by long-wave radiation, ie by heat. But they are not affected by short-wave radiation, ie by light.
Sunlight enters the atmosphere and passes through to the surface. It hits the surface and is converted to heat, warming the surface. The heat is reflected back towards space as long-wave radiation (infrared). The long-wave radiation causes the greenhouse molecules to vibrate which redistributes the energy in all directions: up, down and to the next molecule. The heat takes longer to escape out to space; the heat remains longer in the atmosphere.
Some simple illustrations:
http://spark.ucar.edu/carbon-dioxide-abs...
http://www.epa.gov/climatestudents/basic...
http://hyperphysics.phy-astr.gsu.edu/hba...
http://news.thomasnet.com/IMT/2012/03/06...
Nothing Zippi62 says should be trusted. Carbon dioxide makes up about 10% of all greenhouse gases in the atmosphere, and we have increased it by about 40%. That's a big deal.
While of course no one knows EXACTLY how much warming will occur, the best models suggest that the warming will be enough to cause major disruption our environment, and it will cost trillions of dollars and countless lives.
Green house gas emit co and carbon- di-oxide. so,It is important role in global warming.
Concerning James' claims (hey, I like that alliteration):
"Thicker air" does not cause global warming.
The "ping pong" effect does not cause the ozone hole.
Here are a couple pages that will explain what causes global warming.
http://www.rkm.com.au/ANIMATIONS/carbon-... <== here's the physics.
http://upload.wikimedia.org/wikipedia/co... <== Note that CO2 intercepts a different wavelength than water. In addition, as CO2 warms the oceans, more water evaporates, increasing it's effectiveness.
http://www.school-for-champions.com/scie... <== melting of the Siberian tundra is a very serious problem.
http://fora.tv/2009/08/18/A_REALLY_Incon... <== This is an hour long, but is very good.
The ozone hole is completely different.
It's primary cause was freon, which is no longer put into refrigerators.
And the ozone hole is, slowly, improving.
There's more info on the ozone hole than you need.
https://www.google.com/#q=ozone+hole
And if you look, you'll see no reference at all to CO2, which is the greenhouse gas that's a concern about global warming today.
The problem with "alarmist-science" proclaiming that CO2 or any other GHG (greenhouse gas) is warming our planet towards a catastrophe, is that they can not mathematically prove that a 1.2 molecule in 10,000 molecules increase of CO2 in the atmosphere causes any degree of warming. They just know that it is a GHG. The simple fact that temperatures have been steady for the past 17 years has them baffled. Even the head of the IP CC acknowledges the "pause" in temperatures and welcomes a public debate on the matter here: http://www.thegwpf.org/ipcc-head-pachaur...
" ... “People have to question these things and science only thrives on the basis of questioning,” Dr Pachauri said.
He said there was “no doubt about it” that it was good for controversial issues to be “thrashed out in the public arena”.
Dr Pachauri’s views contrast with arguments in Australia that views outside the orthodox position of approved climate scientists should be left unreported. ... "
Arrogant climate scientists like to think they know more than everyone else, but more modest climate scientists seem to have a real grasp on the extent of GHG warming. They simply don't know how much more warming the extra 1.2 parts per 10,000 of CO2 in the atmosphere causes.
Sports writers have been claiming that the Chicago Cubs will win a World Series since they last won one, but it still hasn't happened yet. Why do people believe sports writers? They don't. They are just analysts just like climate scientists are.
Gasses are produced which cause the atmosphere to become "thicker" which holds onto heat and radiation from the sun longer than a clear atmosphere. We cant feel the air being thicker, but the particles in the gasses are heavier, which creates more pollution and further global warming. The heavier air can reflect heat back down to the earth, and a constant "ping pong" effect happens as heat is reflected too and from the land, heating the atmosphere. This can contribute to the collapse of the ozone, which happens at the poles first. With the ozone breaking down over the ice poles, the heat from the sun is absorbed more in this are as there is little to protect the area (the ozone protects the whole planet from radiation in short). With the ice melting, sea level rises in a term called "isostatic change". The land ice is added to the sea, which rises sea levels, and the more water creates a warmer ocean, which can hold onto even more heat and radiation from the sun.
Greenhouses let heat in but not out.
start at NASA
I need to figure this out for homework!
