Transterrestrial Musings

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>Fortunately, heat radiation goes up as the fourth power of temperature according to the Stephan-Boltzmann Law.

Well yes sort of... Unfortunately CO2 Absorbs at least 50% of all radiation between 2 and 40 microns, which as luck would have it is exactly where the Earths peak radiation is. It works sorta like a greenhouse. Hey wait a minute, maybe I on to something here.

Posted by brian d at October 12, 2007 04:06 PM

> Cutting back $50 worth of gasoline use cuts back one fill up. Cutting back $50 worth of coal cuts back two tons.

Hm.... I'm actually kind of curious now about what the relative carbon output of each is.

Posted by Neil H. at October 12, 2007 06:15 PM

What?

Where did you get that number?

Posted by at October 12, 2007 07:57 PM

Feel free to compare the "heat effects" of atmospheric CO2, at less than 600 ppm, with those of H20, at a couple of orders of magnitude more concentration.

Then tell us where the "absorbed" radiation goes. (What happes as CO2 gets hotter?)

Posted by Andy Freeman at October 12, 2007 09:53 PM

Yeah, my mood has been pretty black today. It's just so utterly amazing to see such a display of thermonuclear moonbattery and self-parody that tops anything The Onion and Weekly World News could jointly conceive. Makes you wonder what's in the Swedish drinking water.

I think you meant "black" in another context...

Posted by Alan K. Henderson at October 12, 2007 11:30 PM

Yes, like "Brown is the new black." when talking about the next color that everyone will be wearing.

The relative amount of carbon between 2 tons of carbon and 93 pounds (about 15 gallons) of hydrocarbon (call it octane c8h18) is about 78/4000 or about 50 times as much carbon per $ of coal vs. gasoline.

A ton of CO2 is 12/44=27% carbon. Look for a $20 tax per ton of carbon dioxide if the government is going for show vs. $20/ton of carbon if they are going for pain.

Posted by Sam Dinkin at October 13, 2007 08:29 AM

Perhaps I should also mention that black never exactly ever gets replaced by whatever "the new black" happens to be du jour.

Posted by Sam Dinkin at October 13, 2007 08:39 AM

If I recall my absorptivity charts correctly, CO2 only absorbs two very tiny wavelength bands between 2 and 40 microns.

Posted by qwerty182764 at October 13, 2007 09:05 AM

This whole thing is ridiculous.

If you go back to the basic physics of CO2, you will find that it is a feedback (dependent on temperature) not a forcing agent.

The current ppm of CO2 is about 385 ppm.

CO2 absorbs in a few bands from 2-17 microns. Water vapor absorbs the vast majority of all IR radiation emitted from the Earth.

Posted by Dennis Ray Wingo at October 13, 2007 10:17 AM

Umm... agreed that "runaway greenhouse" -- by which people usually mean what happened to Venus, hundreds of degrees and water driven off -- is not in the cards. That doesn't mean the consequences of a trivial excursion of 3-4 degrees C. in the global mean wouldn't be pretty ugly.

Coal: a couple of years ago I was talking energy futures with the late Rick Smalley at Rice, including how much coal China is likely to burn through 2050. He observed that we can make big bucks selling them our best clean-coal technology, but "given the downside of that much CO2, you could make an economic case for just putting all the blueprints on a million CD-ROMs and air-dropping them."

(pause)

"Nahh... just one CD-ROM, they've got duplication down pretty well."

Posted by Monte Davis at October 13, 2007 10:25 AM

Y'know, if this global warming thing keeps going, they might be able to raise crops on Greenland, like the Vikings claimed they did.

Posted by Big D at October 13, 2007 11:49 AM

Dennis,
We've had this debate before - what controls the energy balance is emission, which occurs in the upper troposphere, where there is very little water and the temperature remains low.
________
..and yes, coal is very bad news. Economically hard to avoid. Fix coal and you you ar well on your way to addressing this issue. I dont know about West Virgina, they are getting pretty unhappy about mountain decapitation there.

Posted by Duncan Young at October 13, 2007 12:32 PM

"I dont know about West Virgina, they are getting pretty unhappy about mountain decapitation there.
"

And us in the office blame it on the anti-nukes.

I did a GIS permit coverage study once and it would astonish you just how small the percentage of West Virginia has been mountaintop mined.

Besides, in 98% of the cases, they have to put the spoil back on the bench after the pit area has been worked. The top gets put back on.

Posted by Mike Puckett at October 13, 2007 12:53 PM

We've had this debate before - what controls the energy balance is emission, which occurs in the upper troposphere, where there is very little water and the temperature remains low.

You will also note that the IPCC's own prediction that the upper troposphere temperature rise has not happened. They simply ignore the physics of the CO2 molecule and make things up as they go along.

If you are going to use the upper troposphere as your guide, you will find that CO2 still only absorbs about 5% of the infrared energy at those altitudes. I have some of the studies done at this altitude and water vapor is still a large absorber even at 35,000 feet.

Posted by at October 13, 2007 02:18 PM

>Well yes sort of... Unfortunately CO2 Absorbs at least 50% of all radiation between 2 and 40 microns, which as luck would have it is exactly where the Earths peak radiation is. It works sorta like a greenhouse. Hey wait a minute, maybe I on to something here.

>What?

>Where did you get that number?

Mills, A. F., "Heat and Mass Transfer," pp. 558-565 Irwin Press, 1995.

>Then tell us where the "absorbed" radiation goes.
It reradiates about ½ back to earth.

>If I recall my absorptivity charts correctly, CO2 only absorbs two very tiny wavelength bands between 2 and 40 microns.

Nope see Fig.6.33-6.34 from above ref., but it’s more complicated than that as is explained in the text.

>If you go back to the basic physics of CO2, you will find that it is a feedback (dependent on temperature) not a forcing agent.

I’m not sure what this means, CO2 simply absorbs radiation in quite a few broadened long wave bands and reradiates some back to Earth, so when you increase the concentration of CO2 you inhibit the ability of the Earth to radiate to space.

I see that professor Mills has provided us a computer program to calculate the effect. So with a lot of assumptions, when the concentration of CO2 goes from 300 ppm to 400 ppm the absorptance of the earths atmosphere goes from about 0.187 to 0.200.

For the record, I’m about as anti global warming whacko as a person can be, but the numbers don’t lie. Even if the warming effect was large, which I doubt, I don’t think I’d change a thing with regard to our energy policy.

Posted by brian d at October 13, 2007 04:54 PM

> That doesn't mean the consequences of a trivial excursion of 3-4 degrees C. in the global mean wouldn't be pretty ugly.

Or maybe they wouldn't be ugly at all.

Posted by Andy Freeman at October 13, 2007 08:35 PM

>>Then tell us where the "absorbed" radiation goes.
>It reradiates about ½ back to earth.

This thread started with the observation that heat radiation worked as the fourth power of temperature. That swamps constant factors like 1/2.

Posted by Andy Freeman at October 13, 2007 08:39 PM

Brian

Thanks, I like references!

I will check it out.

Posted by Dennis Ray Wingo at October 13, 2007 10:02 PM

Or maybe they wouldn't be ugly at all.

What scientific uncertainty exists, Andy, is concentrated at the level of "how much CO2 leads to how much warming, via what positive and negative feedbacks?"

There is virtually no uncertainty that a 3-4 C increase in global mean temperature (that's at or beyond the high end of the IPCC ranges for the end of the century) would push rainfall and temperature in many heavily populated and agricultural zones way outside anything seen in the last 10,000 years. Even more important, it would do so at a rate that we haven't experienced since "infrastructure" meant framing your hut with mammoth bones.

Those changes and rates of change would be many times greater than those associated with the Dust Bowl or the current Australian drought, and they'd be happening in many places at once. If you can see a smooth global adaptation to that -- no famines or resource wars, Bangladeshis welcomed in Sinkiang and megahectares of waving wheat around Great Bear Lake -- I'd like to hear more. Does your scenario involve flying pigs?

Posted by Monte Davis at October 14, 2007 10:55 AM

And, just to throw more fuel on the fire...

http://brneurosci.org/co2.html

Summary: Doubling CO2 to 730 ppm is unlikely to produce a temperature increase more than 1.6 C / 3 F, and WON'T produce a 3-4 C increase.

3-4 C increase isn't going to happen, so why bother debating its effects?

Question for the knowledgable poster:

Do you have a critique of the linked article that explains why the hypothesis, method, or analytic results are faulty?

Posted by MG at October 14, 2007 11:34 AM

> There is virtually no uncertainty that

Umm, that exact description and equivalents is commonly thrown around in global warming discussions as a lead-in to things that turn out to be debatable at best and often false. (Since the 3-4 degree change is way outside the possible range, wouldn't it have been better to chide your fellow enthusiast instead of defending the irrelevant? That choice suggests that truth isn't the goal.)

How much warmer was it when Greenland was green and grapes grew in the UK?

Posted by Andy Freeman at October 14, 2007 12:07 PM

no famines or resource wars...

I rack my brain to recall a resource war before global warming.
To paraphrase Julian Simon, if you count the percent of people dying of hunger and war the number seems to be shrinking over the last couple hundred years, not growing. More to the point, life expectancy continues to rise.

Let's compare global warming to impoverishment by tripling the price of electricity. Raising energy prices seemed to work wonders in Iran and Myanmar for brotherly love. Maybe that will make up for the loss of money that could be used for other forms of life extension.

Posted by Sam Dinkin at October 14, 2007 02:16 PM

>Thanks, I like references! I will check it out.

Thanks Dennis, you seem like a reasonable person. My original guess of 50% was based on a glance at 2 graphs, but after doing the calculation it turned out to be more like 20%. Anyway the point was that adding CO2 to the atmosphere certainly causes an overall temperature increase, weather (sic, ha ha) that number is 10C or 10 milliC, I don’t know, but it is a positive number (I think that the reference will confirm that). I also think that the case of reasonable people is hurt by denying that there is no increase at all.

> swamps constant factors like 1/2
Not really. Think about it, if you double the temperature without any atmospheric absorption you’d get 16 times the radiated energy, but with ½ being absorbed and returned to Earth, that’s only a factor of 8.

Anyway what you should be paying attention to is my calculation that shows increasing absorption from 0.187 to 0.200 is about a 7% increase. 7% of a large number is a large number. 10.000C or 0.001C, you tell me?

Posted by brian d at October 14, 2007 03:22 PM

> Not really. Think about it, if you double the temperature without any atmospheric absorption you’d get 16 times the radiated energy, but with ½ being absorbed and returned to Earth, that’s only a factor of 8.

The causality goes the other way. The hotter the CO2 is, the more it radiates. That limits how hot it can get. You can't double the temperature - you can barely make it budge.

Posted by Andy Freeman at October 14, 2007 05:56 PM

The way I understand this conversation is:

1) CO2 raises the power input by 7%.
2) Power output is related to the 4th power of temperature.
3) So to math-a-tize it:
Pin1=Z
Pin2=Z*1.07
Pout1=T1^4*K
Pout2=T2^4*K
Pin2/Pin1 = Pout2/Pout1
1.07 = (T2/T1)^4
T2/T1=1.017
T1=~300
delta-T=~5 degrees

Since this is way more than even the priests of Global Warming are claiming, this is obviously not really what is going on... assuming something is going on.

Posted by David Summers at October 14, 2007 07:20 PM

I can't WAIT to hear the wailing in the streets if a $20/ton of anything tax is imposed on coal. Not only will you have the UMW screaming, but every coal-burning utility in the country will jack their electric rates to pass along the cost to consumers.

A $20/ton tax would just about double fuel costs, which is approximately 95% of the cost of generation. Wholesale electricity cost makes up about 60% of the delivered cost, so retail rates would have to rise at least 50% to pay for the tax.

Yeah, I bet THAT would be well received by the fixed-income crowd.

Find another solution to your perceived problem. Personally, I think a little warming of the planet would be a good thing. It's too damn cold around here.

Posted by Dave G at October 15, 2007 05:56 AM

Actually fuel costs are most of the generation costs only for natural gas. For coal plants, it's mostly capital. Enough coal for a kwh of electricity is about $0.006 cents; the price of coal at the mine makes up about 20% of the price. It varies up to twice that for coal plants far from mines, but a $20 coal tax will only add less than one cent to nighttime power and depending on state regulations perhaps less than a half cent to daytime power. It won't do much to curb carbon output though.

Posted by Sam Dinkin at October 15, 2007 09:36 AM

Posted by David Summers
>delta-T=~5 degrees
Yes, I did the same calculation too. You forgot the re-radiation view factor from the atmosphere to earth/space is about 0.5. Add that in and you get delta T =2.5, which is just about what the global warmingists are saying. Still a bit high though and I suspect it’s because my estimation of CO2 absorptance is a bit off. Read through the reference and you’ll see what I mean.

Actually I’m quite impressed that we were able to get such a good result from simplified analysis and we didn’t even have a $10M government grant.

Posted by brian d at October 15, 2007 12:14 PM

>Posted by David Summers
Oops, I missed this part, actually it doesn’t increase the input by 7%, it reduces the output by 7%, but the math gives the same answer either way, delta T =2.5C

Posted by brian d at October 15, 2007 12:20 PM

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