Do we all agree that low CO2 concentration does not preclude it from causing global warming?

Question

I thought this question was very clear:

http://answers.yahoo.com/question/index;_ylt=AufuW0IrMWoiVUFwuT78HxYFxgt.;_ylv=3?qid=20071120090849AAHZCzv

But apparently I have to spell it out.

Many people have argued that because atmospheric carbon dioxide is at what sounds like very low levels (387 parts per million, or 0.0387%), it can't be responsible for the current global warming. There's been another agument that CO2 isn't a pollutant becase it's plant food, but I'll ignore that one because it's irrelevant.

My analogy was that arsenic is toxic to humans at 10 parts per billion (or 0.000001%). You could make the same argument with any number of molecules. Copper is essential to most living things, but toxic at concentrations of around 3,000 ppm (0.3%).

The point is that concentration doesn't tell you anything about an molecule's effect, unless you know more about the molecule, such as its toxicity or its global warming potential.

Can we agree on this?

For the last time, I'm not talking about toxicity. Read the entire question.

Dr. Blob - I think your teacher was onto something. Global warming deniers are proving themselves to be irrational.

Answer 1

The significant factor for CO2 is the molecular absorption cross section determined by its huge dipole transition moment. In the infrared, the absorption cross section of CO2 is 10^11 times larger at fundamental mode frequencies than the absorption cross section of O2 anywhere in the same frequency range. CO2 is less abundant by a factor of 10^-4. The net result is that CO2 is 10^7 times more important than O2 at CO2 fundamental mode frequencies. I asked this question earlier and was disappointed at the level of scientific knowledge in YA.

http://ca.answers.yahoo.com/question/index;_ylt=AsNZwm_3uAbKdi2nz7W9YlzAFQx.;_ylv=3?qid=20070830220446AA8YZpy

Regarding the toxicity of CO2, the question was asked and well answered earlier. CO2 is toxic at 5000 ppm.

http://ca.answers.yahoo.com/question/index;_ylt=ArW3gqp9pMtFhhFJAORsvOvBFQx.;_ylv=3?qid=20070806215340AAkfb8a

Answer 2

No. The sentence "The point is that concentration doesn't tell you anything about a molecule's effect unless you know more about the molecule, such as its toxicity or its global warming potential" makes no sense whatsoever. Toxicity is almost universally defined in terms of concentration. As someone else noted, water and oxygen are essential for life in most organisms, yet those same organisms can die from an excessive amount of either of those substances. Moreover, global warming potential (GWP) is a relative metric. Knowing a greenhouse gas's (GHG's) GWP doesn't mean much in absence of an understanding of the relative scale of GWPs. Furthermore, even knowing a GHG's GWP and concentration is relatively meaningless in absence of knowledge of the quantity of the GHG or the substance in which the GHG is present. Again, I would also point out that comparisons of inorganic substances introduced into living organisms to GHGs introduced into the atmosphere are completely inapt, as organisms tend to bioaccumulate inorganic substances, while GHGs tend to be dispersed in the atmosphere, hence the term global warming, as opposed to local warming. So, no, we apparently can't reach an agreement.

As to people being rational, I think my name conveys my thoughts on that quite precisely.

Answer 3

A bigger green house gas is water vapor. Perhaps Al Gore with his Nobel smarts can figure out a way to eliminate the oceans' evaporation. The oceans are water and salt. Hey, just add a few trillion gallons of Cuervo Gold and limes and he can host a party where everyone drinks them empty. Al Gore's an idiot! Not only did he "invent the Internet," he's invented man-caused global warming via CO2. Next, he'll be claiming to have turned lead into gold and to have invented a perpetual motion machine. We should get the rubber room and straight jacket ready. He'll soon need them.

Answer 4

No, sorry. We don't seem to agree on anything.
You argument would be relevant if CO2 was a powerful greenhouse gas. Arsenic is obviously a VERY toxic poison. CO2, however, is a weak GHG. Methane is 30 times stronger, and of course the strongest and most important GHG is water vapor. CO2 can't even compare to water vapor.
Nice try, but you'll have to come up with something better next time.

Answer 5

No we can't agree on this, there is a blatant impedance mismatch here, toxicity levels of various chemicals are dependent on the nature of the properties of each molecule in question. The amount of infrared light being scattered by a particular molecule are dependent on the absorptivity characteristics of each molecule, the amount of EM energy in the required bandwidths available to the molecule and last but not least, the number of molecules in the atmosphere.

The last 500 million years shows CO2 well above 1000 PPM, for millions of years. Plants evolved in an environment of CO2 levels above 3000 PPM, to make the statement about tipping points occurring because of CO2 levels approaching 400 PPM are unfounded. There is no evidence in the paleoclimate record of atmospheric CO2 levels responsible for controlling climate.

Answer 6

Well of course no one is interested in real stuff regarding the subject of global warming, but, it is quite clear the very thin layer of air covering the surface of Earth has very little effect on the temperature on the planet. The Earth is more than a million times more massive than the atmosphere. That is its not really a tail wags the dog story but the flea on the tail wags the planet.

Answer 7

Yeah Dana, I know what the point you are trying to make is.

It's not the concentration,. it's the effect that's important.

A similar point has been made regarding Al Gore standing next to a big CO2 graph - it's not the (relative) concentration that matters.

I think Jello was implying that your point was getting a bit lost in these fancy analogies you were comming up with. btw, what do you think of his 357 analogy - can you do better?

Answer 8

I said to my instructor once -

"But what rational person would come to that conclusion"

His reply?

"What makes you think people are rational"

edit:
Hmmm. Mr. Rationality, I've read your response several times and it's not making any sense to me. And I'm thinking it's not because I don't get it, I'm thinking it's because it's gobbledygook. My challenge stands.

Funny thing about self reporting. It’s said that incompetent people lack the cognitive ability to recognize their own incompetence, and tend to overstate their abilities.

Answer 9

Adding more C02 to the atmosphere will and has had significant changes. So why wouldn't slowing the emissions have a significant impact?

Answer 10

man your way into global warming im interested in your thoughts but you write a lot and i hate to read things that long but whatever