Why should it matter to me that atmospheric CO2 is a "trace gas"?

Question

I keep seeing posts here that seem to rest their argument that CO2 could never be a problem because (1) the absolute amounts are so tiny, and (2) CO2 is not a toxic gas.

As to #1, nobody disputes that the proportional amount is tiny. So why should that matter?

As to #2, CO2 actually *IS* toxic to humans at high levels (even in the presence of plenty of oxygen). [Recall how the Apollo 13 astronauts had to install make-shift CO2 scrubbers even though they had enough oxygen.] But why should CO2 toxicity be relevant to the debate in the first place? If high levels -- whatever those levels may be -- can be shown to be problematic, the level of toxicity or not and whether the absolute amounts are small is not the crux of the matter.

So are such posts simply a layman's way of remarking, "Hmm. That doesn't seem like much CO2 to me." ?

Am I missing something?

Answer 1

No it doesn't matter, and CO2 is a trace gas , but there is really no connection between these two observations.

Answer 2

As for #1 It matters for one reason, we have not been shown evidence that the tiny proportional amount equates to the "unprecedented" increase in temperature. When you search for evidence you find a grade school explanation that temperature is increasing, CO2 is increasing, CO2 is a GHG, therefore temperature increase is caused by CO2. When you look for a better correlation you are shown models that are able to match temperature trends. When you don't find that convincing your shown more evidence of warming and told that it's unprecedented based on proxy reconstruction. When you look at proxy reconstructions that show it's not unprecedented your told that reconstruction is flawed and there isn't enough evidence to prove it is accurate because the 500 year warming period you are referring too was probably regional. Then your shown more signs of warming, and told weather patterns consistent for areas they occur are more extreme because of global warming. Still not convinced you are asked to prove that the warming is caused by something else and called a denier. When you ask about scientist who don't agree CO2 is major cause of warming you're told those are the stupid scientist and the consensus agrees it's CO2.



#2 Toxicity only matters because alarmist have classified it as a pollutant, when the claim is made that it's not a pollutant and it's essential for life on the planet we get these YA questions and are told, "CO2 actually *IS* toxic to humans at high levels ...". A. We aren't talking about high levels, we are talking about levels that are well below the TOXIC levels.



Classifying CO2 as a pollutant does not increase it's ability to warm the planet and I am still searching for the correlation between x amount of warming to y amount of CO2 and not finding convincing proof.

Answer 3

Jeff M has a point (as well as some nice links): Most of what CO2 can absorb is already being absorbed. (Actually, I think he only meant to point out that CO2 can absorb significant amounts in IR even in its current trace amounts.)



Adding more CO2 will cause convective forces to become more important in transferring heat upward. These convective forces are already making important contributions.

http://resources.metapress.com/pdf-preview.axd?code=vl7536426072q7j7&size=largest

(full text) http://www.springerlink.com/content/vl7536426072q7j7/fulltext.html

This does not mean that adding more CO2 will have no effect, but the amount of effect is highly questionable. Theoretically, adding more CO2 will make progressively less difference.

http://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law

Recently, the amount of CO2 in the atmosphere has been increasing significantly,

http://en.wikipedia.org/wiki/Keeling_Curve

but the global temperatures have not seemed to respond.

http://www.ssmi.com/msu/msu_data_description.html#msu_amsu_time_series

Especially, not at the 6 Km altitude, where the atmosphere would heat up the most if CO2 were the driver.

http://www.realclimate.org/index.php/archives/2004/12/why-does-the-stratosphere-cool-when-the-troposphere-warms/

Warmers try to paper over the problem saying that the results allow a slight possibility that the data could be wrong, and it could still possibly be CO2 doing the warming.

http://www.worldclimatereport.com/index.php/2004/07/19/the-data-weigh-in/



Edit @Paul B:

"water vapour is removed by rain and snow whereas there is no such mechanism for CO2, and that water vapour is a driven amplifier whereas anthropogenic CO2 is a driver."



The ocean provides such a mechanism for CO2 removal from the atmosphere. CO2 longevity in the atmosphere is ~5 years.

http://www2.canada.com/components/print.aspx?id=433b593b-6637-4a42-970b-bdef8947fa4e

The positive feedback mechanism does not over ride Le Chatlier's Principle.

http://en.wikipedia.org/wiki/Le_Chatlier%27s_principle

To do so would be to assume that our atmosphere is in a meta stable condition, not a true equilibrium. The only reason that we have remained in the current state is due to our never having been this warm before. A few more degrees, and our world is destroyed. Ridiculous!

http://commons.wikimedia.org/wiki/File:Holocene_Temperature_Variations.png



Edit @Jeff M:

My apologies. Your point seemed to me to be that despite being a trace gas, it was still quite capable of absorbing significant amounts of IR. I seem to have overstated the case you were trying to make. Nevertheless; good point.



As for the ssmi graphs; the warmers in the literature I linked to made the same point you just did. However, read them again, and you will see that:



All 23 of the models assumed that the 6Km altitude would warm FASTER than the surface. This is due to the need for the CO2 to heat the surface by trapping the heat at that level. When this did not occur, they determined that the 6Km altitude would be a "pivot" point below which it warms, and above it it cools. In the other paper, they tried to discredit the satellite measurements with statistics. Neither paper impeached the negative result.



"Your springerlink doesn't state anything about it being 344ppm in 1878 and suddenly falling to below 300ppm in two years. Actually the number 344 does not exist in that page."

Correct! That information is on the next page. When I first went to that site, the next page was also free, but now you need to put in your credit card to read it. Sorry.



I do not care what Michael Fox endorses. I linked to a literature review by some scientists, and not to a list of signatures. Sorry if you do not like such things sharing space on a hard drive with political petitions. I really did not check out the rest of the site.

Answer 4

It doesn't matter. CO2 is a known radiative absorbing molecule.



http://www.youtube.com/watch?v=Ot5n9m4whaw



If you'll look at the link below and click on the relevant pictures to view the absorption spectrum of both water vapour and CO2 you'll notice that much of the same wave numbers are absorbed by both molecules, except two. The first has a wavenumber around 2500 and the second has a wave number of less than 1000, closer to 500. Now turn on the Earth's emission spectrum overlay. You'll see that the majority of long wave radiation water vapour absorbs has a wave number above 1500 related to the radiation re-emitted by the Earths surface.



http://www.kcvs.ca/site/projects/common_files/IR_Spectrum/IR_spec5.swf



Satellites orbiting Earth have the ability to detect incoming wavelengths of radiation as well as outgoing wavelengths of radiation. This is how they know all the radiation hitting the planet is not re-emitted by the planet into space and how they know that absorption has increased in some of the wave numbers associated with CO2 and other greenhouse gasses (methane) is growing.



http://www.skepticalscience.com/images/harries_radiation.gif



CO2 is toxic at concentrations far in excess of today's concentrations. then again most gasses are. This is one of the main reasons why people suffocate during volcanic eruptions. You can also get it during diving or spelunking.They suffer a condition known as Hypercapnia.



http://en.wikipedia.org/wiki/Hypercapnia



Current estimates of CO2 in fresh air are approximately .04%. However in places such as non ventilated crowded auditoriums it is known that the CO2 concentration gets as high as 1%. The U.S. Occupational Safety and Health Administration state that during an average workday, for safety concerns, exposure should not exceed 0.5%.



Edit: NW Jack... I never stated any such thing. You seem to be misreading and misinterpreting what I said. You also seem to be misreading the graphs in your ssmi.com link. IT states the lower stratosphere is cooling while the troposphere is warming which is exactly what Climate Change theory due to greenhouse gasses states will occur. Your springerlink doesn't state anything about it being 344ppm in 1878 and suddenly falling to below 300ppm in two years. Actually the number 344 does not exist in that page. What it does state is that the CO2 concentration has been consistently rising with one small dip from 313ppm to 309ppm in the third decade of the series. Then you go on to link to the petition project? You mean that petition where over 20,000 signees have what amounts to a BSC and those 4,000 or so with an actual PHD may not even work in the climatology field. On top of that are signees with names such as Michael J. Fox and Ginger Spice. And you know perfectly well that you included it as the last link in your sources.

Answer 5

The argument as used repeatedly here is, it's only a small fraction of the atmosphere so for that reason it can't matter.



that's pure ignorance, spread by people with no interest in truth.



The accompanying argument (already on display here) is that since water vapour is a more abundant and more significant greenhouse gas, CO2 is unimportant by comparison. This argument deliberately ignores the facts that water vapour is removed by rain and snow whereas there is no such mechanism for CO2, and that water vapour is a driven amplifier whereas anthropogenic CO2 is a driver.

Answer 6

Probably has to do with the fact that H2O is a stronger GHG, works on more wavelengths, and is 1-4% of the atmosphere, yet you alarmunists pretend that a weaker GHG, that works on only 3 small bandwidths, makes up <0.04% of the atmosphere is actually the driving force of the climate.



Your viewpoint is quite entertaining, when you take it to the point of believing in 7 degree changes caused by CO2.



Paul,

Your constant referencing of rain and snow taking H2O out of the atmosphere completely ignore that there are HUGE freakin oceans that are constantly putting the stuff back in.



You all crack me up with your garbage. You downplay the effect of H2O, when you know it is a major factor in your feedbacks. The problem with your models though is that because they have such strong feedbacks, they suggest a climate that is entirely unstable and can be driven by a trace gas. If the earth's climate were unstable, you might be on to something, but the earth's climate is relatively stable. The larger changes in temps always follow either changes in the earth's rotation, catastrophic events or solar cycles, never a trace gas. These large changes necessary to see moderate changes in temps point to a stable system. So right off the bat, your models are probably wrong. The fact that your models have been entirely unable to predict the past 15 years of no significant warming, means that your models are overestimating the strength of the positive feedbacks. The fact that you all are unwilling to admit the truth that is so blatantly obvious, means you are horrible scientists. The fact that you use this complete lack of evidence to argue for more government control, reduction of rights, tax schemes and not permitting third world countries from having power plants, means that you are socialists.



You want to talk about good changes that will help the economy and the reduce CO2, you need not show compelling evidence of severe future problems. You want to talk of a tax scheme during a recession and causing innocent people to die in third world countries due to lack of power, then you need more evidence than you have. That's just the way I roll.



NW Jack,

Those are some very informative websites there. Thanks for taking the time to post them. I sure the science deniers (AKA alarmunists) do not agree with them, but they are very interesting.

Answer 7

maybe the limits of access now is not hazardous but what is being spoken about is that there is an increase and so could get to killer levels some day.

Answer 8

Because they think that proponents of AGW are arguing that we're being smothered by excessive CO2. It's just another of their many straw man arguments.