Source

Carbon dioxide absorbs infrared radiation (IRR) in three narrow bands of frequencies, which are 2.7, 4.3 and 15 micrometers (µM). This means that most of the heat producing radiation cannot be absorbed by it.

Heinz Hug* showed that carbon dioxide in the air absorbs to extinction at its 15µM peak in about ten meters. This means that CO2 does whatever it's going to do in that amount of space. Twice as much CO2 would do the same thing in about 5m. There's no significant difference between 5m and 10m for global warming, because there is at least 50 kilometers of significant distance in the atmosphere to get it done in.

Originally posted by Long Lance
There are many ways to spread fear

There are many ways to selectively pick your science too...

From the man's own website:

About the Author: Gary Novak M.S. Microbiology, 1970


In college, I ended up studying science but was forced out by mental pain while in graduate school. Mental pain is not the same as depression or schizophrenia. It's caused by distracting sights or sounds which contact memories containing pain, which are too close to the surface.

Creating the mental pain is totally dependent upon sin, and therefore I felt a need to get systematic in deriving the basics of the subject of morality, which I have been doing for thirty five years...

In graduate school, I studied yeast physiology and stumbled onto the basic control mechanisms of mushroom formation. After being forced out by mental pain, I moved onto the vacated family farm in South Dakota, where I began doing mushroom research...

After getting significant results with mushrooms, I attempted to publish in the science journals but was locked out. Science is a good-old-boys club, and I was an outsider. So I got a computer and put the results on the internet.

More...

Source
A molecule of nitrous oxide has the equivalent greenhouse effect of 206 carbon dioxide molecules, and the CFC molecules have impact 12,000 to 18,000 times that of carbon dioxide. The absorption bands (wavelength regions) for carbon dioxide are nearly saturated, but those for other gases are not, so one additional molecule makes a larger impact. However, we should keep in mind that each person in the US on average puts about 20 metric tons (20,000 kg or 44,000 pounds) of carbon dioxide into the atmosphere from burning fossil fuels each year, compared to 100 kg of methane, 2 kg of nitrous oxide, and 2 kg of CFCs. Multiplying the CFC emission rate by 12,000 gives a CFC greenhouse impact comparable to that for carbon dioxide.

Originally posted by Long Lance
PS: i advise utmost caution whenever the sky is reported falling, see another glaring example of overlooking the obvious: plants emit methane, so much for models and calculations, they're tools, they can be misused, catastrophies sell, he who cries the loudest receives maximum publicity and grants.

Originally posted by Valhall
One thing you stated in your post two up that I totally agree with - the factor of natural methane emissions from botanical sources. The models have got to be corrected for this hither-to unknown source. Prior it was thought that the reduction of CO2 by plants helped mitigate GHGs, and so the thought was as we de-forest we make things worse (which I love trees, so I'm all for stopping that nonsense as much as we can), but now we find they produce methane that is 20% worse in its GHG effects than CO2. I haven't read whether these two things negate each other or not - have you?

Global warming: blame the forests

The following correction was printed in the Guardian's Corrections and clarifications column, Monday January 16 2006

The headline above overstated the more circumspect case outlined in the article below, which said that plants emit up to 30% of the methane, a greenhouse gas, entering the Earth's atmosphere. Scientists have just discovered this, but to conclude that it is a new cause of rising temperatures is mistaken.

According to a study published today, living plants may emit almost a third of the methane entering the Earth's atmosphere.
The result has come as a shock to climate scientists. "This is a genuinely remarkable result," said Richard Betts of the climate change monitoring organisation the Hadley Centre. "It adds an important new piece of understanding of how plants interact with the climate."

Methane is second only to carbon dioxide in contributing to the greenhouse effect. "For a given mass of methane, it is a stronger greenhouse gas, but the reason it is of less concern is that there's less of it in the atmosphere," said Dr Betts.

But the concentration of methane in the atmosphere has almost tripled in the last 150 years, mainly through human-influenced so-called biogenic sources such as the rise in rice cultivation or numbers of flatulent ruminating animals. According to previous estimates, these sources make up two-thirds of the 600m tonnes worldwide annual methane production.

Methane is emitted from a variety of both human-related (anthropogenic) and natural sources. Human-related activities include fossil fuel production, animal husbandry (enteric fermentation in livestock and manure management), rice cultivation, biomass burning, and waste management. These activities release significant quantities of methane to the atmosphere. It is estimated that 60% of global methane emissions are related to human-related activities (IPCC, 2001c). Natural sources of methane include wetlands, gas hydrates, permafrost, termites, oceans, freshwater bodies, non-wetland soils, and other sources such as wildfires.

...

In the United States, the largest methane emissions come from the decomposition of wastes in landfills, ruminant digestion and manure management associated with domestic livestock, natural gas and oil systems, and coal mining. Table 1 shows the level of emissions from individual sources for the years 1990 and 1997 to 2003.

Table 1

And:

Methane emissions from terrestrial plants under aerobic conditions

Methane is an important greenhouse gas and its atmospheric concentration has almost tripled since pre-industrial times1, 2. It plays a central role in atmospheric oxidation chemistry and affects stratospheric ozone and water vapour levels. Most of the methane from natural sources in Earth's atmosphere is thought to originate from biological processes in anoxic environments2. Here we demonstrate using stable carbon isotopes that methane is readily formed in situ in terrestrial plants under oxic conditions by a hitherto unrecognized process. Significant methane emissions from both intact plants and detached leaves were observed during incubation experiments in the laboratory and in the field. If our measurements are typical for short-lived biomass and scaled on a global basis, we estimate a methane source strength of 62–236 Tg yr-1 for living plants and 1–7 Tg yr-1 for plant litter (1 Tg = 1012 g). We suggest that this newly identified source may have important implications for the global methane budget and may call for a reconsideration of the role of natural methane sources in past climate change.

bad move? really, i still remember when everyone feared the projected wholesale loss of forests by the year 2000 or so

now on to some statistics about S02 emissions

Source
Initiated in 1985, the Eastern Canada Acid Rain program committed Canada to cap SO2 emissions in the seven provinces from Manitoba eastward at 2.3 million tonnes by 1994, a 40% reduction from 1980 levels. By 1994, all seven provinces had achieved or exceeded their targets. In 1998, the provinces, territories and the federal government signed The Canada-Wide Acid Rain Strategy for Post-2000, committing them to further actions to deal with acid rain. Progress under both the Eastern Canada Acid Rain Program and under the Post-2000 Strategy, including data on emissions, is reported in the respective annual reports of these two programs. Between 1980 and 2001, emissions of SO2 declined by approximately 50% to 2.38 million tonnes. In eastern Canada , emissions of SO2 declined by approximately 63% between 1980 and 2001.

Source#2
Capture and disposal of CO2 are actively being sought as a means to avoid release of the greenhouse gas to the atmosphere. At the Sleipner West gas field in the North Sea, Norway's state-owned oil company, Statoil, is conducting the world's first carbon sequestration project that has as its main objective protection of the atmosphere (1). CO2, a natural gas contaminant, is being recovered and pumped into a huge aquifer beneath the sea floor. (*) Another project is planned off Hawaii's Kona coast, where a multinational research team will soon perform field trials, testing options for direct ocean disposal of CO2. (**)