Carbon Dioxide's Atmospheric Involvement

[JoshSHill]

G'day there peoples,

 

First of all, if anyone here is actually a qualified climate scientist (or a scientist close to the realm of climate sciences), if you could please contact me via my Skype using JoshSHill, that would be really appreciated.

 

I'm a freelance journalist, and I am continually coming across areas where I need someone's help in.

 

The latest is this question; though carbon dioxide is found only in relatively small amounts in our atmosphere, does any increase exchange for a larger increase in temperature? Or, in other words, even though it's in such a small amount, can it still have the massive effect that some would have us believe?

 

Hope to hear from someone, ANYONE, soon!

Josh

[iNow]

The quick answer is yes.

 

Overall amount is not the important term. The important term is impact by unit change (even if that change is a fractional percentage of the overall system). The easiest analogy I have is this.

 

Just because I change only 1% of the air in your bedroom to toxic nerve gas does not mean that it will have no effect and you will not be killed. It's not the overall amount that matters, it's the effect of the amount which is there... And even in small amounts, the effect can be tremendous.

[Realitycheck]

The quick answer is yes.

 

Overall amount is not the important term. The important term is impact by unit change (even if that change is a fractional percentage of the overall system). The easiest analogy I have is this.

 

Just because I change only 1% of the air in your bedroom to toxic nerve gas does not mean that it will have no effect and you will not be killed. It's not the overall amount that matters, it's the effect of the amount which is there... And even in small amounts, the effect can be tremendous.

 

Would you mind explaining how, historically, CO2 change occurs AFTER temperature change?

 

 

G'day there peoples,

 

First of all, if anyone here is actually a qualified climate scientist (or a scientist close to the realm of climate sciences), if you could please contact me via my Skype using JoshSHill, that would be really appreciated.

 

I'm a freelance journalist, and I am continually coming across areas where I need someone's help in.

 

The latest is this question; though carbon dioxide is found only in relatively small amounts in our atmosphere, does any increase exchange for a larger increase in temperature? Or, in other words, even though it's in such a small amount, can it still have the massive effect that some would have us believe?

 

Hope to hear from someone, ANYONE, soon!

Josh

 

I'm not disputing that man-made CO2 pollution may somehow affect the temperature, but as far as I know, the correlation has not been drawn in the past. What iNow is referring to is heightened concentrations of CO2 in populated areas, which are starting to border harmful.

[iNow]

Would you mind explaining how, historically, CO2 change occurs AFTER temperature change?

I'm not sure that's relevant to this thread, but it's pretty well articulated here:

 

http://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2/

What is being talked about here is influence of the seasonal radiative forcing change from the earth's wobble around the sun (the well established Milankovitch theory of ice ages), combined with the positive feedback of ice sheet albedo (less ice = less reflection of sunlight = warmer temperatures) and greenhouse gas concentrations (higher temperatures lead to more CO2 leads to warmer temperatures). Thus, both CO2 and ice volume should lag temperature somewhat, depending on the characteristic response times of these different components of the climate system. Ice volume should lag temperature by about 10,000 years, due to the relatively long time period required to grow or shrink ice sheets. CO2 might well be expected to lag temperature by about 1000 years, which is the timescale we expect from changes in ocean circulation and the strength of the "carbon pump" (i.e. marine biological photosynthesis) that transfers carbon from the atmosphere to the deep ocean.

So it is not as if the temperature increase has already ended when CO2 starts to rise. Rather, they go very much hand in hand, with the temperature continuing to rise as the the CO2 goes up. In other words, CO2 acts as an amplifier, just as Lorius, Hansen and colleagues suggested.

 

 

 

What iNow is referring to is heightened concentrations of CO2 in populated areas, which are starting to border harmful.

I was more trying to make the point that overall percentage of the atmosphere is not the relevant term. You could have a 20 gallon bucket of water that could be completely diseased with a single microliter drop of some noxious substance... even though that noxious substance doesn't even comprise one tenth of one percent of the total volume under study.

 

 

This link gets the points across quite well:

 

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

[Mr Skeptic]

The latest is this question; though carbon dioxide is found only in relatively small amounts in our atmosphere, does any increase exchange for a larger increase in temperature? Or, in other words, even though it's in such a small amount, can it still have the massive effect that some would have us believe?

 

Yes. Compare to having just an incredibly thin window on your car, it will still heat up far more rapidly than if the windows were open. The essence of the green house effect is that energy goes in more easily than it comes out. In an actual green house or your car, most of the effect is by trapping the hot air. In the atmosphere, the effect is due to absorbing infrared light. Though the atmosphere is transparent to much of the light emitted by the sun, parts of the atmosphere (called green house gases) are more opaque to infrared (which is emitted by warm objects). So energy goes in as higher energy light, but does not as easily get emitted as lower temperature infrared radiation.

[Realitycheck]

Yes. Compare to having just an incredibly thin window on your car, it will still heat up far more rapidly than if the windows were open. The essence of the green house effect is that energy goes in more easily than it comes out. In an actual green house or your car, most of the effect is by trapping the hot air. In the atmosphere, the effect is due to absorbing infrared light. Though the atmosphere is transparent to much of the light emitted by the sun, parts of the atmosphere (called green house gases) are more opaque to infrared (which is emitted by warm objects). So energy goes in as higher energy light, but does not as easily get emitted as lower temperature infrared radiation.

 

Lets see some facts here. I don't buy it. Ozone may act as a "window", but CO2 is dispersed throughout the atmosphere. I want to see how an increased amount of gas that comprises less than 4 hundredths of a percent of the atmosphere can have the effect of increasing the temperature.

[iNow]

Lets see some facts here. I don't buy it.

It's time to spend some time educating yourself, since that is almost exactly what happens.

 

 

http://www.ucar.edu/learn/1_3_1.htm

 

 

Carbon dioxide ([ce]CO2[/ce]), water vapor ([ce]H2O[/ce]), methane ([ce]CH4[/ce]), nitorus oxide ([ce]N2O[/ce]), and a few other gases are greenhouse gases. They all are molecules composed of more than two component atoms, bound loosely enough together to be able to vibrate with the absorption of heat.

 

 

http://www1.agric.gov.ab.ca/$department/newslett.nsf/all/gm10175

 

 

http://globalwarming.house.gov/issues/globalwarming?id=0002

The science of global warming is not new. In 1859, British scientist John Tyndall discovered that carbon dioxide (CO2) can trap heat and in 1896 Swedish scientist Svante Arrenhenius calculated that doubling a the amount of CO2 in the atmosphere could raise Earth’s temperature as much as 10°F. Since Charles Keeling began measuring atmospheric CO2 in the late 1950s, scientists have accumulated a wealth of evidence documenting the increase in CO2 and other global warming gases in the atmosphere, the consequent rise in global average temperature and the influence of human activities on the Earth’s climate.

 

 

Several good articles here:

 

http://www.realclimate.org/index.php/archives/category/climate-science/greenhouse-gases/

 

 

Also, the wiki link I shared in the previous post covers much of this as well.

[Realitycheck]

Was already there. I am just trying to get a decent argument out of you.

[iNow]

Was already there. I am just trying to get a decent argument out of you.

 

So... erm... what is your question, exactly?

[Realitycheck]

It says here that CO2 in the atmosphere accounts for appr. 9% of the greenhouse effect. So if CO2 goes up 20% over 50 years, this would have the effect of the temperature going up about 2 degrees, which is close enough to what has actually happened. It's all actually quite simple.

[swansont]

Lets see some facts here. I don't buy it. Ozone may act as a "window", but CO2 is dispersed throughout the atmosphere. I want to see how an increased amount of gas that comprises less than 4 hundredths of a percent of the atmosphere can have the effect of increasing the temperature.

 

At current concentrations, that atmosphere is already close to being opaque at the CO2 absorption bands at 4 and 15 microns.

 

http://www.scienceforums.net/forum/showpost.php?p=397344&postcount=77

 

So outgoing light gets absorbed and then re-radiated; some goes out to space and some gets directed back toward earth. Instead of radiative cooling to the 3K reservoir of space, you are radiating into a much warmer atmosphere, meaning less energy is transferred away from the earth.

[Chris C]

For those looking for a description of the physics behind the greenhouse effect and the infrared absorption behind CO2, I recommend 3 of my posts as well as "a saturated gassy argument" at realclimate.org .

 

http://chriscolose.wordpress.com/2008/03/09/physics-of-the-greenhouse-effect-pt-1/

http://chriscolose.wordpress.com/2008/03/10/physics-of-the-greenhouse-effect-pt-2/

http://chriscolose.wordpress.com/2008/02/13/just-a-few-more-molecules/

 

Concerning the historical record on why CO2 goes up after temperature, this is because of rather basic solubility principles in chemistry (warmer water cannot hold as much gas so it gets put out into the atmosphere) so CO2 rises after the initial warming, generally caused by orbital variations. When the planet is more elliptical, you get more solar insulation...and it also tilts up and down changing the geographic distribution of solar radiation, mainly influencing albedo. In any case, the radiative forcing from this is rather small, and the feedback from CO2 and methane needs to be involved-- once they increase in concentration, they then play their greenhouse roles and further amplify temperatures (positive feedback). There are other paleoclimatic examples of when CO2 comes first , and the role of CO2 in snowball earth, the faint young sun, the supergreenhouse times of the Cretaceous, the evaporated oceans of Venus, etc make CO2 as fundamental a gas to planetary climates as evolution is to biology.

[iNow]

For those looking for a description of the physics behind the greenhouse effect and the infrared absorption behind CO2, I recommend 3 of my posts as well as "a saturated gassy argument" at realclimate.org .

 

http://chriscolose.wordpress.com/2008/03/09/physics-of-the-greenhouse-effect-pt-1/

http://chriscolose.wordpress.com/2008/03/10/physics-of-the-greenhouse-effect-pt-2/

http://chriscolose.wordpress.com/2008/02/13/just-a-few-more-molecules/

 

Very thorough, Chris. Quite well done, sir. Thank you for sharing this.

[Rev Blair]

Something I'd like to mention to Josh, since he's a journalist, is that the heat-trapping effects of carbon dioxide in the atmosphere, and the variations of CO2/oxygen mix are pretty much tied up with evolutionary theory as well.

 

I'm not a scientist or any sort of expert...just an interested layman...but it's an area of the discussion where the press has been sadly lacking in making the connections. The greenhouse effect was pretty well established before most people (there was discussion in the scientific community) had ever heard of global warming. I learned about it in grade four or grade six, and I'm 43 now.

 

Whenever I hear people doubting the effects of relatively small shifts in our atmospheric makeup, I find myself wondering where (or if) they went to school.