Monday, September 19, 2005 ... Deutsch/Español/Related posts from blogosphere

Latent heat of ice and climate models

This looks like an excellent example how the self-confident climate "big shots" are ignorant about basic numbers in physics and how worthless their reasoning is.

Steve Connor wrote another dramatic article in The Independent claiming that global warming is past the point of no return. Such articles appear virtually every day. They're addressed to the people who know even less than the journalist himself. But the fate of our civilization - always an uncertain thing - is not what I want to mention here.

William Connolley is one of the main driving forces among the 9 people who started the alarmist climatologist propagandistic blog called RealClimate. William is one of the main people who define the "scientific consensus" about the climate. If you believe the "scientists" without calculating it yourself, you believe people like William Connolley.

William also has his own private blog called Stoat. In the newest article, he questioned the statement by Steve Connor that the Arctic sea ice is a major heat sink. In the main text he said that ice couldn't be a heat sink because it reflects solar radiation. So I explained him that when we say that it is a heat sink, we mean that it absorbs the heat particularly from the ocean, not from the Sun. I expected him to realize his error.

Instead, he continued and wrote that the latent heat of ice is completely negligible, and they can forget about it when they work with their climate models. In order for you to see how incredible his statement is, let me say a couple of numbers.

The heat capacity of liquid water is 4,200 Joules per kilogram and kelvin. The latent heat of ice is 355,000 Joules per kilogram. What does the ratio tell you? If you melt ice, you can cool down the same amount (mass) of water by roughly 85 degrees.




Now, there are about 2 meters of ice in average in the Arctic and approximately 2 kilometers of water underneath. Simple counting shows that by melting the ice, you can cool down the whole underlying ocean by 0.1 degrees - the predicted "global warming" trend for a whole decade. (Let's not talk about what's actually happening and what will be happening because this is too politically sensitive a topic.)

Also, the atmosphere is equivalent to roughly 10 kilometers of air. Its mass is like 10 meter high column of water. But because the specific heat capacity of air is just 1/4 of that of water (counted per kilogram), the atmosphere is something like 3 meters of water. That means that 2 meters of ice have enough latent heat to cool down the whole atmosphere above the Arctic by 50 degrees; these are order-of-magnitude estimates meant to evaluate whether an effect is negligible. Alternatively, you may also consider atmospheric CO2 only which is 380 parts per million. The latent heat of the sea ice would be enough to cool down the CO2 in the atmosphere by something like 150,000 degrees if it were possible.

Nevertheless, the latent heat of sea ice seems negligible to William Connolley and probably also most of his colleagues; they prefer the atmospheric CO2 as the object that everyone should look at (especially the 2 parts per million that the humans produce every year). They neglect things such as ice in their considerations. They omit such entities in their models, too. Water is also the most important greenhouse gas (more than 90% of the total effect) but they neglect it as a greenhouse gas, too. They don't care whether one increases or decreases the total amount of clouds and water droplets in the atmosphere. They don't care that the specific heat capacity of water is the highest one after Hydrogen and Helium. Water does not matter for them. What's the real reason that water is not interesting? Well, it's because the evil capitalists produce as much water as the nice communists and ecoterrorists.

They just pick one term - one insight from high school physics - among hundreds of others that they neglect. They apply it to one, politically most interesting gas, and calculate something from this one term and call it science. They want others to believe that they can predict temperature for the next 100 years. The fact that they neglect sea ice that cools down their gas component by 150,000 degrees if it melts does not matter to them. It's negligible, is not it?

Many journalists then transform these "scientific insights" into even more impressive articles, and various politicians use these "improved" insights to fight against the whole civilization. But the scientific basis of these claims is based on totally weird assumptions such as that the latent heat is negligible.

In reality, ice matters. Some glaciers grow; some of them retreat - and the current ratio is not necessarily 50:50 because the laws of political correctness do not apply to mother Nature. The Antarctic ice is growing (this is an argument by NASA that the global warming is not global and it is not exactly warming either), the Arctic ice is diminishing. It's pretty clear that the places with a lot of ice will have more stable temperatures (typically close to 0 degres Celsius) because ice can regulate the fluctuations. The heat capacity including the latent heat is simply large. These are rudimentary insights from elementary school physics and they have absolutely no political flavor if they are understood rationally.

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reader Quantoken said...

Lubos:

That's an excellent post to show why the global warming theory is one of the biggest crackpot theories around. It would be interesting to see how the supporters of GW would respond.

It would also be interesting to analysis, from a social darwinism point of view, how the whole community of researchers in one field could all come to a "consensus" of such a ridiculous wrong conclusion, and call it science. And only some one outside the field, but who has some basic science training, could see through why the "experts" are totally wrong! Such problem exists widely in many fields of modern science research, not just in environmental science.

I believe it is NOT due to the reason that they received poor training in general physics in their first college year. Any one who has taken physics 101 should be able to do such simple order-of-magnitude numerical estimates, regardless of IQ level. But many researchers have lost that capability a few years after they took the college course.

But, Lubos, I have to tell you that climatologist's assertion that the effect of arctic ice, as a heat sink, can be neglegible, is actually CORRECT. The water bodies of the oceans, due to the vast quantity, is actually a MUCH MORE important heat sink to consider, than the ice. Of course, you can not heat up just the ocean but not the crust underneath. So you really should consider the whole earth as your heat sink in your climate model. But because only the surface of the top layer varies considerably seasonally, so in most climate model, they consider the ocean body as a giant heat sink, with the ice supplementing a small amount.

In any case, if you condense all the CO2 in the atmosphere into liquid or solid, 377 ppm is only a thin layer of 3 or 4 milimeter thick. Such a thin layer is very unlikely to "block" and "trap" the heat radiation from the surface of the earth in any significant way.

Even if it does cause significant alternation, so that the equilibrium of solar radiation and the earth's heat radiation into space would be reached at a surface temperature o.5 degree higher than current level. That is only 0.7% extra heat from the sun trapped, at current surface temperature, i.e., 2 watts per square meter of earth surface.

You can calculate, with the ocean as a huge heat sink, and you have 2 watts per square meter extra heat, how long does it take to heat the earth surface up 0.5 degrees? A few days? A few months? Or, rather, a few hundred years? What if you consider the whole earth as a heat sink? The answer will be tens of thousands of years before you would worry about the 0.5 degree temperature raise occurs.

Quantoken


reader William M. Connolley said...

Well Lubos, you're off the deep end again.

First of all, its kind of you to puff me up like that, but I really don't have the status you claim for me.

Secondly, to say They neglect things such as ice in their considerations. They omit such entities in their models, too. is twaddle. Latent heat of sea ice is in the GCMs, of course. I'm curious about where you got the "They omit such entities in their models" - was this off the top of your head, from some septic site, or logical deduction from first principles?

What I was trying to point out to you (and which will obviously take a rather longer post to make clear) is that in the great scheme of things the LH of sea ice isn't much of a heat sink.


reader Luboš Motl said...

Dear William, you say that you wanted to point out that "in the great scheme of things the LH of sea ice isn't much of a heat sink."

Well, that's exactly why I criticized you and still criticize you. Too bad that even after these numbers you can't agree with a trivial fact that the sea ice is an important heat sink.

Hundreds of your colleagues of various types - those who understand oceans a bit - agree with me that sea ice is an important heat sink. Some of them even use it to twist the "scary" climate scenarios in a specific direction. I don't know why exactly you happen to think that it's not.

It's just dumb to use the word "grand scheme of things" that is probably based on rather irrelevant details like the atmospheric CO2 but is "grand enough" to neglect the (huge) latent heat of ice.

I did not mean that everyone who has ever constructed any model about the climate ignore LH of the sea ice; there are thousands of models that people have worked with. I mean that the LH is neglected in models that people like *you* are using to argue "grand" things about the climate. Your reply has made it absolutely clear that you could not have seen a model that counts the LH at least semi-properly because you don't even know that the LH of sea ice is a major regulator of temperature with very significant effect of lowering the fluctuations.

Ice is typically used as a "victim" only. It is rarely considered to be a major player. And the same statement applies to most important natural effect and variables that dictate the climate. You pick one particular effect of one particular politically interesting gas, and claim that you are the master of climate science. The obvious fact that the climate is determined by clouds, rains, hurricanes, and other things - instead of politically interesting gases - is not terribly interesting for you. You don't want to understand cloud formation and rain dynamics properly because it has no political implications.

The word "septic" is spelled "sceptic" or "skeptic" depending on whether you're British.

Best wishes
Lubos


reader Alexander said...

Well, to add to Your discussion a little bit of sauce... I am a global warming alarmist, lets say...
I have studied ecology.
I have NOT studied physics at the University. Just to question: If ALL the physical factors balancing the climate are stable, WHY is the global surface temterature so rapidly rising??? (you certainly admitt, that 0.5 °C rise per century is quite steep). Are rising temperatures caused by urban heat island? Or by activity of the sun? (well, the sun activity is nearing the top of its activity, and the sun is certainly contributing to the climate warming...)
And... to the melting of ice... it is not so simple, as You have pointed out. Is is of course, possible, and maybe probable, that ice in the Antarctic is acumulating, but that is actually THE SIGN of rapidly changing climate... What would happen, if all the ice on the north pole would have melt, and would accumulate on the south pole? (according to resent research, ice extent on the north pole is again record low...)
And the ratio between melting and accumulating of glaciers is far from 50:50... mostly continenal glaciers are melting RAPIDLY and faster than ever. They are melting in Alps, Hymalayas, Ands, Rocky Mountains...
If the climate models will not tell us about the FUTURE, what are telling us animals and plants about the PRESENT? What about the shifting of their habitats to the north? What about the increased wild fire frequency in Siberia, Alaska, Nothern Amerika, India?
What about changing precititation trends? What about changing incidence of drougths? What about greening of Earth?
Im not saying, that CO2 is to blame for every extreme weather event. I say, that CO2 is one of the climate regulating factor and its level in the air is highest in at leats 720,000 years a probably much more...

I am pretty sure, that in less than 10 years is will be finally proved, if global warming is caused by man or not... dont You think?


reader Alexander said...

No nevim, jestli se tu muze psat cesky... snad me nazabijou
precti si tenhle clanek

http://www.sme.sk/c/2390673/Rusi-sa-stavili-ze-na-Zemi-sa-ochladi.html
muzeme se vsadit, ze se klima v pristich deseti letech otepli?:-)
hezky den

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