2011-08-10 18:18:30Joseph Postma on the Greenhouse Effect
Chris Colose

colose@wisc...
69.86.130.70

Another G&T type paper making the rounds, so I have a two part series on it...

http://skepticalscience.com/Postma1.html

http://skepticalscience.com/Postma2.html

P.S. If people have trouble viewing the links, login to http://skept...., not http://www.skept...

Might want to get this out sooner than later too; I have already seen people talking about it...

Also I only split this up for length, so it might be good to post them together and maybe confine comments to just one of them, to keep everything focused on the general topic..

2011-08-10 20:27:10
nealjking

nealjking@gmail...
84.151.48.111

Chris,

at these links, I get:

 

File not found

There is no page at this address.

 

2011-08-10 23:59:01
Chris Colose

colose@wisc...
69.86.130.70

Someone always runs into this problem, and it seems to be fixed by changing whether you use http://skepticalscience.com vs. http://www.skepticalscience.com

Otherwise I'm not sure

2011-08-11 01:03:21
nealjking

nealjking@gmail...
84.151.48.111

Why don't you fix the link?

2011-08-11 01:13:56
Chris Colose

colose@wisc...
128.183.2.130

Those links work for me; I think it depends on which ¨version¨ of Sks you are logged in to. That is what I gathered from John last time I had issues with this. But try this and this.   Let me know if they don´t work either.

2011-08-11 04:02:46
nealjking

nealjking@gmail...
84.151.48.111

Your second versions work for me; but not the first.

Do your second versions work for you, or only the first?

 

What is anyone else's results?

2011-08-11 04:20:24
Chris Colose

colose@wisc...
69.86.130.70

Opposite with me. In any case, one of these sets of links should work for everyone :-)

2011-08-12 01:23:53
jg
John Garrett
garrjohn@gmail...
98.112.44.162

Delightful posts, Chris. I find an explanation of what is wrong with a paper to be very helpful in picking up pieces that help me understand the correct physics (an area I'm weak in). In part 1, I was confused about the /4 and /2 adjustment to incoming solar radiation.  Do I understand correctly: dividing 1370 by 4 approximates the average energy received on a rotating eath; and dividing1370 by 2, would describe the energy received by a non-spinning, one-side-always-to-the-sun planet?

I looked through Postma's paper. I think his inclusion of an experiment to try is clever on his part. Can you comment on the experiment? It looks like a classic flawed experiment.

jg

2011-08-12 04:40:34
Chris Colose

colose@wisc...
128.183.2.130

The total solar radiation that gets to the planet is 1370 W/m2 times the area of a circle, pi r² .  The total emitted power of the Earth is sigma T⁴ times the surface area of the sphere, 4 pi r².

So you equate S pi r² = 4 pi r² sigma T⁴. (forget albedo).  Divide by 4 and the piś and r²´s cancel, so you are left with

S/4 = sigma T⁴. You can go on to solve for T...

All of this can technically be true on any planet, although it is only useful on a planet with a mildly constant T.  If the day side has a temperature much higher than T and the nightside much lower than T, than the model does not tell you much.  In the above statement,the division by 4 is equivalent to assuming that the solar radiation falls uniformly on the entire planet.  On Earth, day is warmer than night, and a spot on the equator is warmer than at the Poles, but in terms of absolute temperature it is not that much.  The variation on Venus is even less. So it is still a useful simple model.  Divinding by two is equivalent to assuming the sunlight is uniformly distributed on the dayside.  In this limit, the dayside becomes hotter than T and the nightside falls close to absolute zero, depending on the thermal inertia, length of day/night, and internal heating might give you a little bit of power too...

You don´t need a rotating planet for any of this (although that helps to keep more of a uniform temperature)...even a tide locked planet that had one side in perpetual nighttime and one in constant daytime could feasibly fall into the uniform temperature limit if it had a thick enough atmosphere to transport heat (this is a hot topic in extrasolar planet studies and habitability interests). 

2011-08-12 06:28:04
Albatross
Julian Brimelow
stomatalaperture@gmail...
199.126.232.206

Nicely done Chris,

Had a quick read, but you might want to check for typos.  I found this one (highlighted):

"Without a greenhouse effect, multiple studies have shown that the Earth collapses into a frozen icwball"

2011-08-12 10:02:21
scaddenp

p.scadden@gns.cri...
161.65.53.59

Great work Chris. I am glad you have done it.

2011-08-13 14:26:45two
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

I'd suggest keeping it split up for the blog post.  We can post them both on the same day, but if combined, it would be super long.

However, if we make this a rebuttal, which we probably should (to 'Postma disproved the greenhouse effect', or something similar), we can combine them into one.

Do you have a link to Gerlich and Tseuchner’s alleged falsification of the atmospheric greenhouse effect?

I made a few edits, mostly just formatting.  It looks good - technical, but it would make a good Advanced rebuttal.

2011-08-13 18:56:58
Rob Painting
Rob
paintingskeri@vodafone.co...
118.93.226.224

Yup, advanced rebuttal for sure. The conclusion = ouch!

2011-08-14 01:08:31
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
97.83.150.37

Nice and understandable, Chris. 

You could have renamed the conclusion "This Postma Doesn't Deliver" for added emphasis.  But that might put it over the top.

2011-08-14 01:18:29
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125
You might also want to add some more section headings (like your Conclusions) to break it up a bit, and help the reader get in the mindset of what's coming next.
2011-08-14 08:16:41
Chris Colose

colose@wisc...
72.226.118.197

Fixed some stuff up, and added a bit more commentary about his statements toward the end of his page 14.

Dana, thanks.  Blog or rebuttal doesn't matter to me, I will let you guys decide. If the latter, do you want me to move this over to the 'Advanced Rebuttal' forum?

2011-08-14 08:24:51both
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

Oh we should do both.  Whenver we create a new rebuttal, we do a blog post and link to that rebuttal in a greenbox at the bottom (which I can add once the rebuttal is set up).

For future reference, you go to "add a new rebuttal" (linked on the left margin in the forum here), which has instructions on how to add a new one if nobody has added your particular myth to the database yet.  But I took care of that for you.

So you just have to go to the rebuttal list and claim the Advanced response to Postma disproved the greenhouse effect (at the bottom of the list, #190).  Then copy and paste your two blog posts in there.  I can take care of the rest.

If you can condense the argument, it would be helpful if you could make an intermediate version of it too.

2011-08-14 14:47:06
Chris Colose

colose@wisc...
69.86.130.70

Advanced done...

2011-08-15 04:56:47greenbox added
dana1981
Dana Nuccitelli
dana1981@yahoo...
69.230.106.125

Okay, I added a greenbox with a link to the rebuttal at the end of each post.  If you get a chance to do an Intermediate version before these are published (on the schedule for Tuesday, US time), either add a link to that version too, or let me know and I'll add it.

2011-08-17 14:58:23Added finishing touches to the postma rebuttal
John Cook

john@skepticalscience...
124.177.173.40

Added a short URL so you can direct someone to http://sks.to/postma and it automatically redirects to Chris' rebuttal - hopefully this will be the go-to-address for anyone encountering Postma citations in an onlie discussion.

Also tweaked the settings to the Postma rebuttal now appears on http://www.skepticalscience.com/argument.php although I'm not 100% happy with the one-liner. Saying "it contains errors" is not really a rebuttal - an effective rebuttal requires a plausible alternative explanation, something understandable but also with a bit of meat in it (while still restricted to 100 characters, a challenge, I know).