Is CO2 the worst greenhouse gas? If not what is?

Answer 1

No, it's water vapor.

Answer 2

When sunlight reaches the surface of earth, some of it is absorbed and warms the earth. Because the Earth's surface is much cooler than the sun, it radiates energy at much longer wavelengths than the sun (see black body radiation and Wien's displacement law). Some energy in these longer wavelengths is absorbed by greenhouse gases in the atmosphere before it can be lost to space. The absorption of this longwave radiant energy warms the atmosphere (the atmosphere also is warmed by transfer of sensible and latent heat from the surface). Greenhouse gases also emit longwave radiation both upward to space and downward to the surface. The downward part of this longwave radiation emitted by the atmosphere is the "greenhouse effect." The term is in fact a misnomer, as this process is not the primary mechanism that warms greenhouses.

The major natural greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect on Earth (not including clouds); carbon dioxide, which causes 9-26%; methane, which causes 4-9%; and ozone, which causes 3-7%. It is not possible to state that a certain gas causes a certain percentage of the greenhouse effect, because the influences of the various gases are not additive. (The higher ends of the ranges quoted are for the gas alone; the lower ends, for the gas counting overlaps.)[2][3] Other greenhouse gases include, but are not limited to, nitrous oxide, sulfur hexafluoride, hydrofluorocarbons, perfluorocarbons and chlorofluorocarbons (see IPCC list of greenhouse gases).

The major atmospheric constituents (nitrogen, N2 and oxygen, O2) are not greenhouse gases. This is because homonuclear diatomic molecules such as N2 and O2 neither absorb nor emit infrared radiation, as there is no net change in the dipole moment of these molecules.

Answer 3

Mt_zion is right, as far as he goes. But it's not the whole story.

The terms "greenhouse effect" and "global warming" are used badly by many people. Greenhouse effect is the larger category, global warming is a part of the greenhouse effect. More:

"Greenhouse Effect" is the effect of greenhouse gases, primarily water vapor, that hold heat close to the Earth. It's mostly a natural process and is necessary to keep the Earth reasonably warm.

"Global Warming" is excessive greenhouse effect caused by man, primarily by releasing carbon dioxide (another greenhouse gas) from burning fossil fuels. Left unchecked it will flood coastal cities and severely damage agriculture.

The graph below is good. The tiny teeth are plants naturally controlling the greenhouse effect. In summer they absorb CO2 and it goes down. In winter it goes up. The big push upwards is us, burning fossil fuels.

http://scrippsco2.ucsd.edu/graphics_gallery/mauna_loa_record/mlo_record.html

We're messing up nature, and we need to fix that.

Answer 4

Not CO2 or water vapor so much. Both of those gases were found in large concentration in the atmosphere throughout the Earth's history, especially CO2. And methane is a lesser greenhouse gas, because there was a lot of it from decomposing dinosaur poop when they lived, and we're fine today.

The truly harmful gases in the atmosphere are SO2 (sulfur dioxide), NO2 (nitrogen dioxide), and O3 (ozone, when found at low altitudes) . These gases not only contribute to global warming, but they are also very toxic to living things.

Answer 5

'Worst' is not the correct word. Without the greenhouse effect of the most abundant and influential greenhouse gas of all, water vapor, the earth would be very very cold.

Answer 6

The plants are taking care of the CO2 and doing a good job.
The methane green house gas ,u have lost it .I can not find even a trace of it.

Answer 7

it may be considered the worst just because there is so much of it...

Answer 8

methane and chlorofluorocarbons