2010-08-31 13:59:06ADVANCED 31: CO2 effect is weak
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

I put together a first draft of the advanced rebuttal to the 'CO2 is weak' argument.

 

One problem I had was creating the lambda symbol.  I couldn't get the Mac keyboard shortcut to work, and when I tried copying and pasting the symbol from other sites, it was replaced with a question mark (same problem for delta, but I just replaced it with a 'd').  Does anyone know how to fix this problem?

 

This is my first Skeptical Science post, so any suggestions would be appreciated.  Is it too long?  Did I make some of the explanations too basic for an advanced rebuttal?

2010-08-31 18:16:51Feedback
John Cook

john@skepticalscience...
124.186.162.78

Dana, this is great stuff. Firstly, I don't think there's such a thing with Advanced rebuttals - we've done all our trimming and dumbing down in the Basic and Intermediate rebuttals. In the Advanced rebuttals, it's time to go nuts! :-)

I did a bit of cleaning up of the HTML code. I can fix the lambda symbol when it goes live - I think it's a glitch of the WYSIWYG editor and will need to probably hardcode it into the raw HTML.

2010-09-01 06:15:43thanks
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99
Cool thanks John.  Any other suggestions?  Is it okay if I link the page in a Yahoo Answers question to get some feedback?  The users there helped me improve the wiki article it's based on.
2010-09-01 07:45:56More feedback, the better
John Cook

john@skepticalscience...
124.186.162.78
If you know any of their emails, feel free to ask them to contact me via john@skepticalscience.com if they want an invite to the authors forum (but please don't post my email publicly).
2010-09-01 07:47:30Btw, goinglive
John Cook

john@skepticalscience...
124.186.162.78
Btw, Dana, people cant view the preview unless they have access to the authors forum. So I'll make your rebuttal live. Note - you can still tweak and edit it after it goes live.
2010-09-01 08:17:48lambda
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

Okay thanks John, I'm fine with it going live.  It's in pretty good shape, but I've now asked for input from the Yahoo Answers users using the live link.

When you get a chance, don't forget to fix the lambda symbol. 

Then I guess the next step is some sort of blog post?

2010-09-01 09:28:49Fixed the lambda symbol
John Cook

john@skepticalscience...
124.186.162.78

Had a light bulb moment, it was because the rebuttals were latin encoded. I changed it to UTF8 encoding. I went through this whole issue with the translations - should've done the proper encoding with the rebuttals also. Latin works fine for "plain English", not so much for advanced rebuttals :-)

I've also tweaked the images, made them all maximum of 500 pixels wide.

Let me know when you're happy for this to go as a blog post and I'll go live immediately. That's 2 advanced rebuttals now. Only 117 to go! :-)

BTW, the URL for the advanced rebuttal is:

http://www.skepticalscience.com/empirical-evidence-for-co2-enhanced-greenhouse-effect-advanced.htm

2010-09-01 09:57:30tomorrow
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

Thanks John, I'll probably be happy with it tomorrow.  I already got one good suggestion from an Answers user to add a reference to the climate sensitivity values, so I added a link to the IPCC report.

I'm also almost done with another advanced rebuttal (got a jury summons today and was dismissed, so I had the afternoon off to work on it).  But that's a subject for another post.

2010-09-01 10:09:45Other rebuttals
John Cook

john@skepticalscience...
124.186.162.78

I was looking at that wiki and there are some other fantastic resources there - did you write them all? There was a great one on climate sensitivity which would make a great advanced rebuttal to "Climate Sensitivity is low"

Look forward to hearing from you re going live. Excited to "launch" our first advanced rebuttal (well, Ned's was first but this will be the first blog post... well, Ned's was a blog post but that was before we'd... argh, you get the idea).

2010-09-01 13:17:28Green Options wikis
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

I pretty much wrote all the climate-related wikis on Green Options.  A couple of them had some other contributors.  There's a user named Dawei who wrote one or two of the myths in the Myths wiki, which is sort of our much smaller version of Skeptical Science.  I think he might be interested in contributing here too.  I offered to pass along your email address if he is.  I also wrote a few of the wikis on alternative fuel vehicles, and one on carbon footprint calculations.

I was thinking about adapting the climate sensitivity wiki, but wasn't sure if it was advanced enough to be the advanced rebuttal.  Maybe it is - I haven't compared it to the intermediate rebuttal.

2010-09-01 13:29:12Climate sensitivity rebuttal
John Cook

john@skepticalscience...
124.186.162.78

I've been meaning to update my climate sensitivity rebuttal for ages - I've been thinking of replacing it with the blog post:

http://www.skepticalscience.com/Working-out-climate-sensitivity.html

As for Dawei, yes, please do give him my email and have him get in touch with me if he's interested in joining the Authors Forum.

BTW, all your work on the Green Options wiki rocks! :-)

2010-09-01 13:58:21thanks
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

Thanks.  I reference my wikis a lot in Yahoo Answers, but other than that not very many people see them, so it's nice to be able to get the information on a more heavily trafficked site like Skeptical Science.

That's a really good climate sensitivity blog post.  I really like the figures, especially the first one.  I bet we could combine it with my wiki and come up with something pretty good.  We've got a 3-day weekend coming up, so maybe I can take a stab at it this weekend.

2010-09-02 06:03:54blog post
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.249
Okay, I'm happy with it anytime you want to do the blog post, John.
2010-09-02 09:20:41Last minute thought
John Cook

john@skepticalscience...
124.186.162.78

 

Just had a thought - what about including in this post the measurements of outgoing longwave radiation by satellites? Here's what I had in the Intermediate version:


Satellite measurements of outgoing longwave radiation

In 1970, NASA launched the IRIS satellite that measured infrared spectra between 400 cm-1 to 1600 cm-1. In 1996, the Japanese Space Agency launched the IMG satellite which recorded similar observations. Both sets of data were compared to discern any changes in outgoing radiation over the 26 year period (Harries 2001). The resultant change in outgoing radiation was as follows:


Figure 1: Change in spectrum from 1970 to 1996 due to trace gases. 'Brightness temperature' indicates equivalent blackbody temperature (Harries 2001).

What they found was a drop in outgoing radiation at the wavelength bands that greenhouse gases such as carbon dioxide (CO2) and methane (CH4) absorb energy. The change in outgoing radiation is consistent with theoretical expectations. Thus the paper found "direct experimental evidence for a significant increase in the Earth's greenhouse effect".

This result has been confirmed by subsequent papers using more recent satellite data. The 1970 and 1997 spectra were compared with additional satellite data from the NASA AIRS satellite launched in 2003 (Griggs 2004). This analysis was extended to 2006 using data from the AURA satellite launched in 2004 (Chen 2007). Both papers found the observed differences in CO2 bands matching the expected changes from rising carbon dioxide levels. Thus we have empirical evidence that increased CO2 is causing an enhanced greenhouse effect.


I also go into more detail in a blog post The increased greenhouse effect - comparing models to observations:

We also have a high degree of confidence in the amount of heat trapped by increased carbon dioxide and other greenhouse gases. This is otherwise known as radiative forcing, a disturbance in the planet's energy balance. We can calculate with relatively high accuracy how much heat is trapped by greenhouse gases using line-by-line models which determine infrared radiation absorption at each wavelength of the infrared spectrum. The model results can then be directly compared to satellite observations which measure the change in infrared radiation escaping to space. What we find in Figure 1 is the observed increased greenhouse effect (black line) is consistent with theoretical expectations (red line) (Chen 2007). These results can also be double checked by surface measurements that observe more infrared radiation returning to Earth at greenhouse gas wavelengths (Evans 2006). Again, independent observations raise our confidence in the increased greenhouse effect.

Increased greenhouse effect -  models vs observations
Figure 1: Increased greenhouse effect from 1970 to 2006. Black line is satellite observations. Red line is modelled results (Chen 2007).


 Also more in the blog post Have American Thinker disproven global warming?:

 What do models predict will happen with rising greenhouse gases? Less longwave radiation will escape at the absorptive wavelengths of greenhouse gases such as carbon dioxide and methane. As the atmosphere warms, it will emit more radiation over the whole longwave spectrum. So we expect to see an increase in outgoing radiation over some of the longwave spectrum with sharp drops at certain wavelengths. This is indeed what is observed, consistent with model simulations.


Figure 2: Observed difference between 1970 to 1996 over the central Pacific (top). Simulated difference over the central Pacific (middle). Observed difference for 'near-global' - 60°N to 60°S (bottom) (Harries 2001).

The top curve in Figure 2 is the observed difference between 1970 and 1996 over the central Pacific. This shows strong agreement with the middle curve which is the modelled results. The bottom curve is the observed difference for a near-global area. Observations are consistent with our theoretical expectations of how the greenhouse effect should behave. The close match between observation and simulation lead the paper's authors to conclude "Our results provide direct experimental evidence for a significant increase in the Earth's greenhouse effect that is consistent with concerns over radiative forcing of climate". One wonders how Gary Thompson missed this conclusion as it's stated both in the paper's abstract and in the concluding paragraph.

There is much else that can be gleaned from Figure 2. Interestingly, the near-global observations show a greater drop in outgoing longwave radiation at the CO2 wavelengths around 700 cm-1 compared to the change over tropical regions. Does this indicate the change in greenhouse effect is greater at higher latitudes? It's also worth noting that the data doesn't cover the entire longwave spectrum as CO2 absorption below 700 cm-1 is not shown.


Some of this is probably worth a mention in the Advanced version - what do you think?
2010-09-02 14:01:03but which argument
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

I think that might almost be better to add in the "it's not us".  Decreased outgoing longwave radiation is a signature of the enhanced greenhouse effect (another 'fingerprint'), but doesn't necessarily help quantify the radiative forcing or rebut the 'CO2 is weak' argument.

So I think it might go better in the other rebuttal.  What do you think?

2010-09-02 15:39:00I'd use it in both
John Cook

john@skepticalscience...
124.186.162.78

Isn't the enhanced greenhouse effect and radiative forcing essentially the same thing? In this case, the studies by Harries et al don't quantify the exact radiative forcing as their data don't extend over the entire infrared spectrum. But what do they find is that over the observed spectrum, the observed change in outgoing infrared radiation matches simulations.

This is basically independent confirmation of one of your sections "Surface measurements of downward longwave radiation" - this is just another way of obtaining the same result - less heat escaping to space = more heat returning to Earth.

So I'd use the info both in "CO2 effect is weak" and "It's not us" - brevity is not an issue in the Advanced rebuttals.

BTW, this is neither here or there but these days, I like to call it the increased greenhouse effect - "enhanced" makes it sound like a good thing :-) 

2010-09-03 01:40:18
dana1981
Dana Nuccitelli
dana1981@yahoo...
38.223.231.249

Well my only issue is that the decrease in outgoing longwave radiation doesn't help quantify the radiative forcing or amount of warming.  But I did add a brief section mentioning that the decreased outgoing radiation confirms the increased greenhouse effect.  Take a look, see what you think.

I passed along your email to Dawei today, by the way.  He's a student without a lot of free time, but I told him that contributing in the forums would be valuable too.  So you should be hearing from him in the near future.

2010-09-03 09:14:19Published
John Cook

john@skepticalscience...
121.222.93.62

I see where you're coming from - the gist of your article is that we have quantified the human contribution and satellite measurements don't quantify the actual amount.

One could argue that we've quantified the human contribution through simulations and the satellite measurements provide confirmation of the simulations in the parts of the spectrum where they overlap. But now I'm splitting hairs and what you've written is fantastic, I'm publishing the blog post right now.

2010-09-03 12:26:53agreed
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99

Yeah that's what I tried to say in the added section.  But I still feel that's more appropriate for the 'it's not us' argument, and I went into a bit more detail about it here.

Thanks John, I think it turned out really good.  Climate science can get so complex that it's nice to have something you can run the numbers on and confirm for yourself.

2010-09-04 15:12:09comment
Robert Way

robert_way19@hotmail...
142.162.188.138
sweet article
2010-09-05 00:19:01thanks
dana1981
Dana Nuccitelli
dana1981@yahoo...
71.140.3.99
Thanks Robert :-)