Shots Across The Bow: Global Warming--the real story

January 3, 2003

Global Warming--the real story

Ok, folks, time for another science lecture from yours truly. Sorry, SK, it isn't on nuke power this time, but that's your fault for getting this whole global warming thing going! By the way, for those of you who haven't checked it out, there's a nice lttle exchange going on in the comments to SKBubba's post here. True to my style, I have to break out of there, and go long form.

Hope you all took naps, because this could take awhile.

In all seriousness, this is an important issue, and you have to understand the basics before you can evaluate the laims of the various sides. I don't want you to just take my word for it; that would be just as bad as the greenies who believe just because Ralphie tells them to. Check out the links I provide. Check their references. Go get a basic science text out of the library, or at the used book store.

Ok, first we have to talk about the proposed mechanism of global warming. Simply put, the global warming theory says that man is in effect putting a blanket over the entire planet by emitting greenhouse gases, primarily CO2. The theory says that the CO2 rises into the upper atmosphere where it acts as a one way heat sheld, trapping radient energy from the sun, and causing the earth to heat up.

Why does that make the earth heat up?

Glad you asked. Now we venture into the world of thermodynamics. It's a little scary in here, but don't worry, I'll hold your hand.

Heat is transferred across a difference in temperature. If you hold something hot next to something cold, the temperature will equalize between them, as heat energy is transferred from the hotter item to the colder item. The rate of the transfer is driven by the difference in temperature between them; the larger the difference, the faster the transfer. Here's the key; without a difference in temperature, no transfer takes place, and energy transfers always go from hotter to colder. Remember this. It's key to why global warming cannot occur as the current model states.

OK, now, there are three ways that this heat energy can be transferred;

Conduction--the two items are in direct contact
Convection--the two items are separated, but a transfer medium envelops them both. This can be air, water, whatever.
Radiation--the two items are separated, but energy is transferred without a medium. This is how the sun warms the earth through a vacuum.

So the sun warms the earth directly, through radient energy. That energy is trapped on the earth by our atmosphere through the greenhouse effect. But how does it work, exactly?

OK, first, the sun is the radient body. It send energy to the earth which absorbs it, growing warmer. Once the earth is warmer than the atmopsphere, it becomes a radient body, transferring energy to the atmosphere via conduction and convection. As the atmosphere warms, the temperature difference between it and the earth decreases, slowing the transfer rate. This allows the earth to hold more of the sun's energy, staying warmer. Eventually an equilibrium is reached, where the rate energy is radiated to the earth by the sun is equalled by the rate energy is radiated by the earth into space. Luckily for us, this equilibrium occurs at a temperature we find comfortable.

Now, global warming theory suggests that man-made greenhouse gasses are accumulating in our atmosphere, shifting the equilibrium point higher. The gasses build up in our upper atmosphere, in effect pulling a blanket over the planet.

Now, in order for our blanket to have a warming effect, it must slow the heat transfer from the lower atmosphere, aka the troposphere, to the upper atmosphere, beyond the greenhouse layer. Like we stated above, the rate of heat transfer is affected by the difference in temperature. Therefore, we should see an increase in temperature in the greenhouse layer if it is causing the equilibrium shift.

As has been noted in many places, tropospheric temperatures are not increasing; in fact they are decreasing. As we have learned, thermodynamically this would mean that heat transfer would increase, cooling the earth, rather than heating it.

The second link above attempts to explain away this discrepancy by positing the presense of contaminants in the stratospheric layer, which artificially reduce the temperature of the troposphere.

While a combination of human activities and natural causes has contributed to rising surface temperatures, other human and natural forces may actually have cooled the upper atmosphere. For example, natural events such as the eruption of Mt. Pinatubo in 1991 tended to decrease atmospheric temperature for several years. And burning coal and oil for energy produces tiny aerosol particles in the atmosphere that can have a cooling effect. Upper-air temperatures also can be reduced by depletion of ozone in the stratosphere caused by chlorofluorocarbons and other chemicals being emitted into the atmosphere. When these variables are accounted for in atmospheric models, satellite and balloon data more closely align with surface-temperature observations.

Thermodynamically, this makes no sense. The cooling effect noted results primarily from blocking solar radiation above the troposphere, resulting in a cooler troposphere and a cooler earth. the drop in both allows the equilibrium to shift and stabilize at a lower level. This is readily demonstrated by observations following Mt. Pinatubo's eruption in 1991, which are well documented. The presence of aerosols in the stratosphere results in cooling in both the troposphere and the surface.

But we are seeing rising surface temperatures and cooling tropospheric temperatures. How can this be?

Let's look at the thermodynamics again. We said that heat transfer is driven by temperature differential. We are begining to see a larger differential, so it stands to reason that the energy transfer rate has increased as well. remember that the earth is in equilibrium with energy input from the sun equalling energy radiated into space. If we are radiating more energy, then we must also be recieving more energy; otherwise the earth would be cooling. Let's take a look at the amount of energy the sun is sending us. Lo and behold, we find that we are in a peak of solar energy output. In fact, if we graph what we know of global surface temperature against solar activity, we find a very close correlation. The following chart, reproduced from this site, and originating from

Baliunas, S. and Soon, W. (1995) Astrophysical Journal 450, 896-901; Christensen, E. and Lassen, K. (1991) Science 254, 698-700; [sbaliunas, wsoon@cfa.harvard.edu].

demonstrates this correlation.

Thermodynamically, it all makes sense. More energy is transferred from the sun to the earth, resulting in a higher surface temperature, which causes a higher differential temperature from the earth to the stratosphere, resulting in more heat being radiated out, maintaining equilibrium.

Anybody still awake?

Good, cause now it gets really fun. The enviros will cry out at this point about the "tons of emmissions we are producing every year, through our wasteful ways, our SUV's, and such. Surely that has some effect?"

Well, let's take a look. The accepted figure for human related CO2 emissions is 5.5 gigatons of carbon per year. That's 11 trillion pounds of carbon! That's monstrous, isn't it?

Well, not really. The atmosphere already contains about 750 gigatons of carbon. In addition, the earth exchanges about 150 gigatons of carbon with the atmosphere yearly. So we have an equilibrium of 750 gigatons, with a dynamic exchange of 150 gigatons, and we are worried about 5.5 gigatons?

Ok, if CO2 emissions were the only factor in the greenhouse equation, then we might need to worry in 300-400 years. The cumulative effects could begin to cause problems in that time span, but that hardly means we need to panic now.

However, CO2 is not the only factor. In fact, it is a minimal factor in the overall greenhouse effect. Water vapor, both as humidity and cloud cover, represents a tremendous heat shield and far outweigh the effects of CO2. Even a massive increase in atmospheric CO2 would only have a small effect on the greenhouse effect.

So, why the big fuss? If there's nothing to worry about, why are all the scientists concerned?

Well, first, not all the scientists are concerned, and some who were are no longer as concerned. Remember, scientists are very conservative. Once a position is adopted, regardless of whether it is sound or not, it takes a long time to get them to change their mind. Look at how strongly Einstein resisted quantum theory. Add to this natural conservatism the current political and ideological climate, and it is much easier to go along with the flow, rather than to stand against it.

Ok, this post is almost done, but now it's my turn to equivocate. The earth's surface temperature is rising. It is possible that man's activities has something to do with it. It is also possible that this is a bad thing. But it hasn't been proven yet. It hasn't even come close to proof. Even so, some are using this possibility to extort billions from the US, and that is all Kyoto was designed to do. If we do find evidence that man is changing the earth's climate, AND we have evidence that this change will be abd, then we should act. As of now, both possibilities are remote. They are worth exploring, but no more.

Posted by Rich at January 3, 2003 9:59 PM

Comments

Very well stated. A nice argument against the "big oil" rally cry of the left.

Posted by: Justin on January 4, 2003 12:13 AM

Rich, that's a pretty excellent and thorough analysis.

I won't pretend to understand all the science (I've only read it three times, and I'll read it a few more times once my head stops hurting) so I will presume that you know what you are talking about and all this is all valid (which seems a pretty safe bet).

I'm glad you recognize, though, that there is still much we don't know and don't understand, and that it shouldn't all just be summarily dismissed as merely a partisan political issue.

And I agree wholeheartedly that extorting the industrialized nations based on science that not everyone is sure about or agrees on is not a good idea.

But, just one little quibble. Doesn't your analysis basically prove that CO2 and other so-called "greenhouse" gasses are necessary to maintain atmospheric equilibrium with regard to temperatures necessary to support life, and therefore are basically a part of the "design" of our planetary environment and ecosystems?

Then wouldn't it also follow that artificial production of such gasses inserted into the equation could upset that equilibrium?

I agree that there may be too little data to prove conclusively that this is occurring and that it may be hundreds or thousands of years before the effects are fully known and understood. But it's just a thought.

OK, then.

(And thanks for taking the time to prepare and walk us through this lesson in atmospheric thermodynamics).

Posted by: SK Bubba on January 4, 2003 12:37 PM

The greenhouse effect is absolutely necessary for life on earth. Without the warming effect of our atmosphere, we would be as cold as the moon. However, the amount of CO2 we are putting into the atmosphere is far to small to be a short twerm danger, and I'm speaking of a geological short term, ie several hundred years. Something I didn't really go into (because I'm not fully up to speed on it myself) are the feedback mechanisms which maintain conditions on earth at an equilibrium. Just as an example, as the CO2 in the troposphere builds up, plants flourish. They grow faster and stronger, which in turn releases more oxygen, restoring the original balance. There are literally hundreds, if not thousands of these feedback mechanisms, all acting to maintain the status quo. (Ironically, the Kyoto treaty would have helped to hasten the destruction of one of these feedback mechanisms, by allowing developing nations to continue clear cutting their forests, reducing their ability to scrub CO2.) These mechanisms are what make it so difficult to model the effects of global warming.

Have you heard the butterfly wing analogy? It's used to describe chaos theory to non-mathematicians, like us. According to the description, a butterfly beats it's wing in Africa today, causing a hurricane to develop over Florida next Tuesday. In a system that complex, that chaotic, predicting the results of a miniscule shift in temprerature is basically impossible. However, we can look at the historical record, and see what conditions were like when the global mean was elevated. In the Middle Ages, roughly 1000 years ago, temperatures were a few degrees warmer than they are today. There are no records of meteorological disasters, superstorms and the like, although there were lots of plagues. Was that due to the increased temps, or the poor living conditions? Maybe both.

I have a small quibble with your use of the term artificial. All animal life produces greenhouse gases. One of the greatest contributers to methane emissions is not the infernal combustion engine, but bovine flatulence.

Yep, cow farts.

I have a hard time calling anything we humans do 'artificial.' That suggests that we are apart from nature, somehow different from all the other animals on the planet. You begin to run into all kinds of pesky little problems with religion, science, evolution, and the divinity of man when you walk down that road. We are animals, just the same as that farting cow, and our activities and their consequences are no more artificial than the ecological destruction which accompanies a beaver's dam.

Posted by: rich on January 5, 2003 2:10 AM

Just remember, I'm not a meteorologist, I just play one on-line....

Posted by: rich on January 5, 2003 2:11 AM

Oh, yeah, Rich has completely made me realize how stupid I was to bother to study all of this and it's supporting documentation:

http://gcmd.gsfc.nasa.gov/Resources/FAQs/glob_warmfaq.html

When I could have just had it explained to my by a guy who "plays a meteorologist on line."

I mean, I went from being mostly one of a "the greenies who believe just because Ralphie tells them to" (I mean, a NASA scientist's plus like 1200 others opinion didn't really carry that much weight with me, naw, I always just listen to Ralph) to somebody who now has "a hard time calling anything we humans do 'artificial."

Actually, I have a VERY easy time thinking that it doesn't get much more "artificial" than the arguments pasted together against global warming. Well, there is one thing that goes beyond "artificial" to just plain FAKE: the assertion that environmental objectives are somehow anti-growth, or worse, a way to "extort billions from the US." Funny, China just bought a maglev from Germany. D'ya think that Germany's self-imposed limitations on old, polluting tech have led to a leadership in new, clean tech? How many Yukon Denalis has China purchased?

PS: don't bother challenging me to a debate on global warming. YOU have, in my eyes, decided take on Dr. Hansen with me as the audience. And, as usual, you got your ass kicked, pal.

Posted by: a different chris on January 6, 2003 3:40 PM

1. For every reputable scientist who subscribes to human derived global warming, there is another who believes it is false. Additionally, truth is not subject to a numbers game. Most believed the earth was the center of the universe when Copernicus came out with his heliocentric theory. He was right; the majority was wrong.

2. If man's actions are artificial, please describe how and why man separated himself from nature. Include in your discussion why it is that man's most destructive tendencies are directly linked to instinctive behaviors, ie the most 'natural' behaviors.

3. If the Kyoto treaty were not an open attempt to extort money from the wealthiest nation on the planet, why were there mechanisms in place for the US to purchase emissions credits in order to continue putting the same amount of GHG into the atmosphere? Why were the rules rigged so that the US could not take credit for it's green spaces, which actually absorb more GHG than the US produces? Why did the Treaty not actually reduce GHG emissions by an appreciable factor?

4. A few quotes from one of the links from your citation:

To counteract this imbalance, the temperature of the surface-troposphere system would have to increase by 1.2°C (with an accuracy of ±10%), in the absence of other changes. In reality, due to feedbacks, the response of the climate system is much more complex. It is believed that the overall effect of the feedbacks amplifies the temperature increase to 1.5 to 4.5°C. A significant part of this uncertainty range arises from our limited knowledge of clouds and their interactions with radiation. To appreciate the magnitude of this temperature increase, it should be compared with the global mean temperature difference of perhaps 5 or 6°C from the middle of the last Ice Age to the present interglacial.

First off, remember that the temperature of the surface has risen, but the troposphere has dropped, negating the initial premise of this analysis, which I point out, is two years old. The system temperature has not risen, but diverged. As I pointed out, this gives a higher heat transfer gradient, which will negate the cooler tropospheric temperatures dampening effect on radiative losses. The feedbacks, as I stated, are very complex, and it is not at all certain what their magnitudes are, leading to major uncertainty of their effect on temperature.

Notice that the paper immediately uses the worst case, 4.5 degrees as it's benchmark for comparison. Very few climatologists believe this extreme number is accurate, clustering more around 1-1.5 degrees C.

As discussed in Chapter 5, these are potentially important indirect effects of aerosols, resulting probably in a negative radiative forcing of as yet very uncertain magnitude.

If you want to radically alter the way we live, you have to do better than "probably" and "very uncertain magnitude." These are code words for "We don't have a clue; all we can do is guess."

The amount of carbon dioxide, for example, has increased by more than 30% since pre-industrial times and is still increasing at an unprecedented rate of on average 0.4% per year, mainly due to the combustion of fossil fuels and deforestation.

QUESTION:If a 100% increase by most estimates will result in a warming of 1 to 1.5 degrees C, and we are increasing at 0.4% per year. How many years before we double our CO2 and get that 1 degree C increase?

ANS 1.004^x=200 Solve for x

177 years before we see our 1 to 1.5 degree increase by the best estimates.

Certainly that is enough time to study the problem to see if the numbers are accurate. Remember, we're dealing with modeling uncertainties several times larger than the effects we are trying to study. In short, by the report you cite, the problem is worth study, but not panic.

But thanks for reading, and for the reference.

Posted by: rich on January 6, 2003 9:02 PM

Thanks, Rich, for your brilliant work. Now the next step is expose all the environmental terrorists for what they really are: a bunch of displaced communists who have been hiding behind the facade of environmentalism to pursue their anti-west, anti-private property, anti-liberty agenda. The University of Virginia scientists for years have also been compiling tons of data like yours that refutes the global warming junk science. But somehow the liberal media conveniently ignores their work. Keep up the great work!!

Posted by: Jim on January 14, 2003 3:18 PM