2010-08-09 13:38:30BASIC rebuttal 24: Water vapor is the most powerful greenhouse gas
James Frank

james.e.frank@gmail...
71.178.147.221

Here's my first attempt. A personal favorite because a friend of mine cites it all the time. I'm no climate scientist, so please correct me if I got anything wrong.


Water vapor is the most powerful greenhouse gas

What the science says: Water vapor is the most dominant greenhouse gas, which creates a positive feedback loop that contributes to global warming.

When skeptics use this argument, they are trying to imply that an increase in CO2 isn’t a major problem. If CO2 isn't even as powerful as water vapor, which there's already a lot of, adding a little more CO2 couldn't be that bad, right? What this argument misses is the fact that water vapor creates a positive feedback loop in the atmosphere—making any temperature changes larger than they would be otherwise.

How does this work? The amount of water vapor in the atmosphere exists in direct relation to the temperature. If you increase the temperature, more water evaporates and becomes vapor, and vice versa. So when something else causes a temperature increase (such as man-made CO2), more water evaporates. Then, since water vapor is a greenhouse gas, this additional water vapor causes the temperature to go up even further—a positive feedback.

How much does water vapor amplify CO2 warming? Studies show that water vapor feedback roughly doubles the amount of warming caused by CO2. So if there is a 1° change caused by CO2, the water vapor will cause the temperature to go up another 1°. When other feedback loops are included, the total warming from a 1° change from CO2 is actually about 3°.

So skeptics are right in saying that water vapor is the most dominant greenhouse gas. What they don’t say is that the water vapor feedback loop actually makes temperature changes caused by CO2 even bigger.

2010-08-09 13:58:42Tweet sized
James Frank

james.e.frank@gmail...
71.178.147.221
As a bonus, tweet sized: As #co2 increases temperatures there is more water vapor, the most powerful greenhouse gas, amplifying the effect and causing #climatechange
2010-08-09 15:05:10Great treatment, suggestion re Tweet
doug_bostrom

dbostrom@clearwire...
184.77.83.151
"causing #climatechange" --> "increasing #climatechange?" ?
2010-08-09 17:53:13Suggested amended tweet
John Cook

john@skepticalscience...
121.222.17.49

Agree with Doug, CO2 is already causing #climatechange so water vapor is increasing it. As I'm always trying to trim characters in my tweets, here's my suggested new version:

As #co2 causes warming there's more water vapor, the most powerful greenhouse gas, amplifying the effect and increasing #climatechange

2010-08-10 03:47:45Suggestions
John Russell

jr@johnrussell...
82.70.63.102

Generally, I like this rebuttal.

Can I suggest the point is made that water is evaporated from the land and sea and is falling as rain or snow all the time. Thus the amount held in the atmosphere as water vapour varies greatly in just hours and days as result of the prevailing weather in any location. So even though water vapour is the greatest GHG, it is relatively short-lived. On the other hand CO2 is removed from the air by natural geological-scale processes and these take a long time to work. Consequently CO2 stays in our atmosphere for years and even centuries. A small additional amount has a much more long-term effect.   

A few minor points.

I don't like the, 'right?' at the end of the sentence -- well, not unless you are going to go on to say, "...wrong!"  It's a bit colloquial.  I'd prefer '...could it?'

The first time the words a 'positive feedback loop' is used, I'd suggest " ...what scientists call a 'positive feedback loop'..." (with the newly-introduced phrase in inverted commas). 

Rather than; "...the total warming from a one degree change from CO2 is actually about three degrees."  I'd suggest "...the total warming from a potential one degree change caused by CO2 is, in reality, as much as three degrees."

Like jfrank, I ain't no scientist; so don't be worried about offending me!

Best wishes,

JR 

    

2010-08-10 03:52:21Interesting link
Robert Way

robert_way19@hotmail...
24.224.230.112
Hello All, while on this subject, here's an interesting link which maybe does not refer specifically to this argument but certainly is a good way of looking at a corresponding issue

http://tamino.wordpress.com/2010/08/08/urban-wet-island/
2010-08-15 16:47:28More detail?
gpwayne
Graham Wayne
graham@gpwayne...
81.152.239.255

Hi James - good stuff there, but I was wondering if mention of residence times was appropriate. CO2 residence is lengthy, but water vapour is laregly a function of immediate temperature (weather, in other words) so while adding CO2 to the atmosphere causes warming and will carry on doing so, water vapour increase is a result of that warming, not a catalyst for it.

There's one other thing about water vapour I just don't quite understand. Is is not the case that water vapour is not homogenous in the atmosphere? Surely there is very little of it in the Atacama desert, and a lot of it in the jungles of Thailand during the monsoon? If this is true, what is the relevance of water vapour distribution, if any?

2010-08-16 09:39:56Fundamental Differences between CO2 and Water
Alden Griffith

agriffit@wellesley...
65.96.213.148

I agree with gpwayne about residence times.  It's important to convey the fundamental difference between co2 and water that makes the skeptics' argument pointless:  if we wanted to warm the planet by pumping it full of water vapor, it wouldn't work because it would all rain out very quickly.  If we wanted to warm the planet, long-lived, well-mixed greenhouse gases such as CO2 and methane would be the way to go.

Alden 

2010-08-17 15:34:10Residence time
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Could combine residence w/C02 by pointing out water vapor will not be able to return to preindustrial levels until C02 allows that to happen?
2010-08-18 14:21:59
Brendon

bpywell@iinet.net...
124.170.75.247

I thought it was pretty good and have no more to add that hasn't already been said.

I kind of disagree with adding "residence" into this argument, unless it is also added to the Intermediate level.

2010-08-18 14:45:39Vote
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Go!
2010-08-19 05:54:27Bump
doug_bostrom

dbostrom@clearwire...
184.77.83.151
Needs some thumbs...
2010-08-19 12:12:40Comment
Robert Way

robert_way19@hotmail...
142.162.181.139

James,
It is a good post and I like it but I may suggest putting in the °C signs next to the temperature amount. Many people who read this blog are used to °F

Also I would like to point out this website
http://tamino.wordpress.com/2010/08/08/urban-wet-island/

Might have something of interest for your post

 

2010-08-19 12:48:46
Michael Searcy

scentofpine@yahoo...
72.91.223.97

I like it.  I do agree that the fundamental differences between water vapor and CO2 are worth mentioning.  Water vapor's short residence time keeps it from becoming well-mixed and from driving long-term climatic changes.  As a result, water vapor concentration varies massively both laterally and vertically, and it can only reinforce trends initiated elsewhere.

CO2, being both long-lived and well-mixed, can accumulate, enabling it to drive long term and global changes.

2010-08-19 21:37:05Residence
John Russell

jr@johnrussell...
82.70.63.102
Residence time -- not that I would use that phrase -- is essential to the rebuttal because it's the reason why water vapour is not as critical as CO2. Once people understand this it completely demolishes the sceptics' argument. In fact it makes them look daft for even deploying this argument. Which is what we want! 
2010-08-19 23:10:51Residence
James Frank

james.e.frank@gmail...
71.191.120.49
Yes, I don't think we can use the term "residence time." I had no idea what you meant when I first read it. I'll have a go at rewriting it soon.
2010-08-20 05:59:38Residence time
John Russell

jr@johnrussell...
84.92.176.215

If you read my second para in my first comment in the thread, you might find some of the words you need, James -- I was trying subtly to offer you the words I think you should include. :-)

Best wishes,

JR 

2010-08-20 20:35:42Twitter title suggestion
gpwayne
Graham Wayne
graham@gpwayne...
217.44.86.17
Climate change: Water vapour makes for a wet argument
2010-08-25 18:15:44My kingdom for a thumb
gpwayne
Graham Wayne
graham@gpwayne...
217.44.86.17

Gets my vote...

(James - if you like my Twitter title suggestion, put it at the top of your post, but leave the 'serious' heading in place below it)

2010-08-26 03:34:13nit-pick
nealjking

nealjking@gmail...
91.33.112.139
"most dominant" should => "dominant"
2010-08-26 04:09:10
Anne-Marie Blackburn
Anne-Marie Blackburn
bioluminescence@hotmail.co...
212.139.81.253
Ready to go
2010-08-26 17:01:24Minor correction. Character minimized Twitter suggestion.
villabolo

villabolo@yahoo...
76.93.65.8

"(Such as man-made CO2)"

James. I know that you did not mean it that way but the phrase "man-made CO2" (2nd paragraph) might confuse some in the public, giving them the impression that there's such a thing as 'synthetic' or 'artificial' CO2.

A better phrase would be, "increased CO2 from fossil fuels".

* * * * *

Suggested tweet below with 125 characters/spaces. 

As #co2 warms earth there’s more water vapor, most powerful greenhouse gas, causing more heat which amplifies #climatechange

This one has 117 characters/spaces.

#co2 warms earth, making more water vapor, most powerful greenhouse gas, amplifying heat, increasing #climatechange

 

This one has 114.

 

#co2 warms earth, makes more water vapor, most powerful greenhouse gas, amplifies heat, increases #climatechange

 

 

 

2010-08-27 03:37:04Great argument, makes the point well, suggesting a couple of proofs.
Niamhaill

niamhwynne@yahoo.co...
109.255.157.58

 

Line 2 - powerful as water vapor, which there's already a lot of - I'd change to "powerful as water vapor, of which there's already a lot,".  Some people are picky about grammar!

Line 2 - couldn't be that bad, right - I'd prefer "couldn't be that bad, could it?"  Probably just that I hear "right" way too much.

 

Good to go!

 

2010-08-28 06:47:43I am going to cross reference this with Rebuttal #31.
villabolo

villabolo@yahoo...
76.93.65.8

Fantastic and simple! Thank you very much. Since there is common ground between #24 and my rebuttal #31, I am going to cross reference mine with yours.

VILLABOLO

2010-08-28 18:09:16at the beginning
nealjking

nealjking@gmail...
91.33.114.10
"most dominant" should STILL => "dominant"
2010-08-29 13:50:14Query rerevision
John Cook

john@skepticalscience...
124.187.125.135
James, just wondering whether you were planning to revise your rebuttal with any of the suggested changes? Eg - include anything about residential times or villa bolo's comment on manmade co2. The rebuttal looks good but just need to know if you're going to make any last changes before I publish.
2010-08-29 14:16:29
villabolo

villabolo@yahoo...
76.93.65.8

 

MY BAD! I did a boo boo and unintentionally gave a second thumbs up. I assume you're not allowed to do that. Sorry.

2010-08-29 17:24:09Second thumb
John Cook

john@skepticalscience...
124.187.125.135
If I was a thorough programmer, I'd have made that impossible - I'll tighten up the code when I get the time :-)
2010-08-29 18:08:00In favour of adding residence times
James Wight

jameswight@southernphone.com...
58.105.164.221
I think the residence time thing is pretty important.
2010-08-29 18:21:49Updating text
John Cook

john@skepticalscience...
124.187.125.135
I'm happy to update the text myself - I think James original rebuttal is excellent and John Russell wrote a good explanation of residence times so am happy to graft the two together. But if James Frank wants to do the edit himself, that would be a better option as it is his rebuttal.
2010-09-02 09:40:27Published
John Cook

john@skepticalscience...
124.186.162.78
I've gone ahead and made the edits myself and just posted this one.
2010-09-02 22:08:57Thanks
James Frank

james.e.frank@gmail...
71.178.154.171

Thanks, John and John. Sorry I wasn't faster on that. I've been pretty busy between work and wedding plan, and this was on my list of things to accomplish before I head out of country for two weeks on Sunday, but then I saw you beat me to it. :-) It looks good to me.

I won't tie up any other arguments at the moment, since I'm not going to be able to contribute a whole lot until November (I hope there will still be something left to do then!)

Didn't realize I was being waited on for an answer here--John, any luck with an email notification feature?

2010-09-03 17:30:27Email notification
John Cook

john@skepticalscience...
121.222.93.62

Will put that next on the to-do list, yes, really is an important feature.

You're getting married?! When's the big day?