...or so says The Independent.
What they are talking about is the decline of Arctic sea ice over the last few years. Fair enough, it has, and (from memory) the trend is about in line with (pre|post)dictions.
One (one?) thing that looks odd in there is: the Arctic sea ice, the northern hemisphere's major "heat sink" that moderates climatic extremes. No. The arctic sea ice *isn't* a major heat sink. In fact, as the article makes clear a bit later... Sea ice reflects up to 80 per cent of sunlight hitting it but this "albedo effect" is mostly lost when the sea is uncovered. "We've exposed all this dark ocean to the sun's heat so that the overall heat content increases," he explained. Yes, thats right, *removing* the sea ice makes the ocean a heat sink, but with the ice in place its pretty reflective.
Commenting on my own post... how dull. Anyway, while waiting for a virus check to finish, I ended up at slashdor, which I don't usually visit, and found this same study discussed.
So many comments, and to so little purpose, since none of them know what they are talking about :-(
You get extra points for spotting the refs to me, and to RP.
I am not sure about the journalist, but you seem to be confused about the direction in which the sea ice acts as a heat sink.
When we say that the Arctic sea ice acts as a heat sink, we of course mean that the ice (on the surface) absorbs the heat from the ocean, not from the atmosphere (and not from the Sun).
The ice induces vertical circulation of the ocean in which both the salt concentration as well as temperature remain correlated and dynamical; that's essentially the thermohaline circulation. See for example this PDF file.
Does the long-term melting trend (which overlays the annual cycle) make it a heat sink for these purposes? I've never heard it described in those terms, although I suppose anything that absorbs heat is a heat sink in a literal sense.
Steve, Lumo: the sea ice is a negligible heat sink. Its 1-3m skim of water on top of a 1-3km thick ocean. Compared to the ocean its heat capacity is negligible. Thinking of it as a heat sink is a mistake. It *does* strongly affect the air-ocean fluxes by insulaing the warm ocean from the cold air, and by affecting the albedo, but thats a different matter.
your response is a bit painful. I was expecting that you would admit your minor error - everyone does a silly error at some time. Instead, you seem to grow a bigger error. ;-)
You say that ice is not heat sink. Let me tell you a couple of trivial things from physics that does not seem to be your cup of tea.
The latent heat of ice is 335,000 Joules per kilogram. The specific heat capacity of water is 4,200 Joules per kilogram and kelvin.
Imagine that I want to cool down water by some "disastrous" temperature difference, for example 0.1 degree of Celsius. This is the type of temperature change that causes, according to scientists like you, the judgement day. ;-)
How much water may I cool down by 0.1 degree with 2 meters of ice on the surface? Note that the ratio of 335,000 and 4,200 is nearly 100. It means that the latent heat of ice is enough to cool down the same amount of water by nearly 100 degrees. It also means that 2 meters of ice can cool 2 km of water beneath it by 0.1 degrees.
It's the whole ocean losing 0.1 degrees. I can melt one half of the ice, still "saving" 0.05 degrees for the whole ocean.
Your comments make it clear that the latent heat of ice is something negligible for you - and you probably neglect these things in your climate models. Then you should not be surprised if others consider your models worthless. The error that you allow to have for the whole ocean is 0.1 degrees if you don't have a problem with neglecting the latent heat. This is enough to annihilate any predicted temperature change for 10 years.
And the latent heat is just one among hundreds of crucial things that climatologists like you neglect every day. You only want to understand 1% of the actual relevant physics effects, yet you claim that you know enough to predict the future.
Now I noticed your comment about the "isolation from the cold air" as the primary thing. Is this a joke? If you don't isolate ocean from -50 degree Celsius temperatures, the result will be that ice will be created nevertheless.
The general theme I find completely shocking is that how much you indeed seem to think that water (and ice) is irrelevant and negligible. Water is completely critical. After Hydrogen and Helium, water has the highest specific heat capacity among all materials you can imagine. The latent heat is huge, too. And water is the #1 greenhouse gas.
Atmosphere is what is negligible in these calculations of the ice melting. The mass of the atmosphere is something like 10 kilometer high column of the air. Its mass is the same thing as 10 meters of water because the ratio is around 1,000. Because the specific heat capacity of air is 4 times smaller than water (it's per kilogram), the heat capacity of the atmosphere is roughly equal to the heat capacity of 3 meters of water. By melting 2 meters of ice, the latent heat is enough to cool the whole atmosphere almost by 100 degrees.
These are the things you are ready to neglect, aren't you? Moreover, you would only prefer to look at CO2 which is 380 ppm of the atmosphere. You think that the latent heat of ice is negligible. You apparently do not care that it is enough to cool down your favorite CO2 part of the atmosphere by 300,000 degrees, if it were possible. ;-)
I just wonder whether everyone in climate science is so unable to perform such elementary "intellectual steps". ;-)
All the best
"How much water may I cool down by 0.1 degree with 2 meters of ice on the surface? Note that the ratio of 335,000 and 4,200 is nearly 100. It means that the latent heat of ice is enough to cool down the same amount of water by nearly 100 degrees. It also means that 2 meters of ice can cool 2 km of water beneath it by 0.1 degrees.
It's the whole ocean losing 0.1 degrees. I can melt one half of the ice, still "saving" 0.05 degrees for the whole ocean."
I don't follow you. You talk about the water underneath the ice cooling by 0.1 degrees, then say that the whole ocean cools by 0.1 degrees. Surely the whole ocean would cool down by a lot less, since the area covered by ice is much lower than the total surface area of the Earth covered by oceans.
Of interest here might be a paper by Levitus et al, who calculated the latent heat due to the melting cryosphere over the last few decades and compared it to the increase in heat content of the oceans and atmosphere.
when I talk about "the whole ocean", I mean, of course, the Arctic ocean.
I am not talking about the "global weather" because "global weather" is an oxymoron and silliness. Let me leave "global weather" to William and likes. This is about the actual relevant physical mechanisms that regulate the temperatures in the Arctic (and Antarctic) region.
There are very different phenomena that become essential closer to the equator, including the moisture in the stratosphere above the tropes. But they neglect these things as well.
Do I expect well that this resolves all of your confusion? See my blog, motls.blogspot.com, for more stuff about the latent heat.
"when I talk about "the whole ocean", I mean, of course, the Arctic ocean."
Okay, but then wouldn't you expect heat transport with the other oceans, which would moderate the cooling?
Similarly your calculation of the atmospheric cooling only considers the column of air above the ice, so that your figure of 100 degrees is not for the "whole atmosphere" as you assert. The cooling for the whole atmosphere would be much smaller.
Leaving aside these details, I looked at your blog article and you seem to be making far too much of a deal about what (I believe) amounts to a rather small oversight by William. Indeed, he never stated, as you claim, that the "the latent heat of ice is completely negligible, and they can forget about it when they work with their climate models." You are attacking a strawman. You also fail to substantiate your claim that climatologists "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."
I posted on Lubos's blog pointing out that indeed the ice is not the most important heat sink, however the bigger picture is that the global warming theory is completely wrong. Not in the basic premise that CO2 traps heat, but wrong in the quantitative calculation how much the temperature could raise. The number has been exagerated by several orders of magnitude.
Two things to consider regarding order of magnitude: 1.The Global Warming effect on the Venus, which we observe and no one objects to that evidence. But consider that the Venus has a atmospheric CO2 that is 10^5 thicker than the earth's, and the temperature only raises 350 degrees. Reduce the Venus CO2 by 10^5 times to reach the earth level, it would also reduce the Venus global warming by 10^5 times, from 350 degree to 0.0035 degree.
This (0.0035 degrees) is also what I expect the earth's actually CO2 related global warming, because the layer of earth atmospheric CO2, if condensed to liquid, is only 3 or 4 milimeters thick.
The next thing to consder is all the fossil fuel we burn to release extra CO2 to atmosphere, was actually ancient biomass which absorbed the CO2 in the atmosphere in the first place. So we are simply releasing the CO2 trapped by ancient plantations in the first place, right back to where those CO2 belonged in the first place.
Prior to life ever originated on earth, there was no free Oxygen. There was instead 20% CO2 in the atmosphere, i.e., 200000 ppm of CO2. That's 600 times higher than today's level. If today's CO2 level is enough to heat up by 0.5 degree, 600 times more of the stuff must have heated the earth by 300 degrees. The temperature would have been so high that life simply could not have originated because no life could survive at that temperature.
But the matter of the fact is the earth temperature with 200000 PPM of CO2 was actually quite a pleasant spring time temperature and life DID originated under the nice condition, which is why humen exist in the first place.
Now, one final argument would render the whole discussion totally un-necessary, whether you still agree with GW or not: The earth has a finited amount of fossil fuel to be extracted and burned. When all the fossil fuel is burned, you would have contributed the maximum amount of CO2 into atmosphere and after that, you can not add more CO2 because you simply do not have any source of carbon to add more.
That amount is actually quite limited!!! There are no more than 1.2 trillion barrels of oil reserves left underneath the surface of the earth and it is reasonable to believe all the big oil fields have been discovered already. 1.2 trillion barrels is all we have. And at 30 billion barrel a year, we are running it out very fast. Once it's gone, it's gone.
You can calculate how much extra CO2 we can add to the atmosphere, if we burn all the 1.2 trillion barrels of oil we still have left. It's actually quite small. My calculation shows it will add another 20 ppm, to the current 377 ppm. That's quite a small amount. But we do not have more.
And the fact that we will burn out of oil pretty soon, is a much bigger crisis than the fact that the CO2 will reach 397 ppm!!!
well, welcome to Stoat.
1 - the GHE isn't linear in CO2. You can't just rescale Venus's. "everyone" agree the earths natural GHE is about 30K.
2 - fossil Co2: it wasn't all in the atmos at the same time
3 - early CO2: faint young sun.
4 - there are plenty of other fossil fuels (coal etc) on top of oil.
If you seriously believe that we won't increase CO2 beyond 400 ppmv, then I'd be interested in betting with you. If you seriously believe that the human-influenced cliamte trend is so small as to be essentially zero, then are you interested in betting on a 10-year trend? Lumo wimped out: see here.
First I would like the cosmotologists point to me where is the quantitative physics model relating CO2 thickness to the quantity of corresponding GW effect. Every where I look there is only a qualitative description that "CO2 traps heat". I need to see the physics model, and quantitative formula how much infrared radiation certain amount of CO2 absorbed, the cross section of photon absorption of CO2 molecules, etc. Without the detailed physics model, you really don't know how much GW 377 ppm CO2 could contribute.
I do expect some none-linearlity in the relationship, but as we know all none-linear system has a linear approximation when the quantity involved is a small amount. Without seeing the quantitative physics model I can not comment further on the none-linearlity part.
Now the 30 K GW, most part of it is attributed to water vapor as that's the consensus even within climatologists. CO2 is but a small contributor to the 30 K. How small? Again I need to see the physics model.
I do not understand what you mean in your second point, fossil not all in the atmos at the same time. The amount of carbon exists in fossil fuels puts a maximum amount of CO2 you could potential release to the atmosphere. If the resource is limited, then the amount of CO2 is also limited. Calculate a bit and you find the limit is pretty low, when divided by how big the surface of the earth is.
The faint young sun argument is invalid. The life exists on the earth in significant quantity for no more than 200 million years. That is a rather short time period comparing with the evolution of the solar system, which is about 4.6 billion years. For all purposes, on the very first day life was born on earth, the solar system was no longer a young infant, but a fully grown up star system and it has been radiating pretty constantly ever since. The near constness of solar radiation is the whole condition that temperature on earth has always been comfortable for life to have evolved. And indeed the slight fluctuation of solar radiation, is the major reason climate changes over centuries.
Also, keep in mind, once life has originated, it quickly prospered to occupy the whole earth. So the transition from a O2-free-and-all-CO2 atmosphere to the 20%-O2-and-CO2-depleted atmosphere life today. Occurred during a very short time period, so short that the solar radiation should not have changed much. Such a vast change of CO2 clearly had NOT resulted in any significant or catastrophic climate change, since nothing like that kind had been registered in any fossil evidences.
I would like to bet you on the 400 ppm CO2. But I am afraid none of us could live long enough to see if it ever happens at all. Or I am not even sure if any of us could survive the oil crash, or has any oil left in the tank of the cars to go drive and collect the bet from you. See www.peakoil.com
Whats a "cosmotologist"? Climatologist? Climate modeller?
"Without the detailed physics model, you really don't know how much GW 377 ppm CO2 could contribute."... how very true. But it hasn't stopped you having a fixed opinion, despite having read none of them!
For the source of the radiation code... if you can bear it, hacking through the misconceptions on this sci.env thread you'll find various souces.
The GHE effect isn't even vaguely linear (its log at the concs we're talking about), and going from Earth to Venus is a big step so asserting linearity won't work.
For WV, you may find http://www.realclimate.org/index.php?p=142 helpful.
Not in the atmos at the same time? You said: "So we are simply releasing the CO2 trapped by ancient plantations in the first place, right back to where those CO2 belonged in the first place." Which is wrong: it wasn't all there *at the same time*. It was in rocks and/or the ocean.
Faint young sun: you said "Prior to life ever originated on earth". I assumed you meant that. Life on earth is... oh, billions of years. Many of your other figures are equally dubious.
Betting on CO2: CO2 is already at 375, and increasing at at least 15 ppmv/decade. If you seriously believe it won't top 400, then a 15 year timespan should be adequate to bet over. Do you have 2000 GBP to bet, and are you prepared to autheticate yourself? I must admit I never thought I'd find anyone who would bet on less than 400, so I've never seriously considered this before.
BTW, you didn't answer bet-on-T.
Correction: a bit more than 15 years. 20 should do. If you're serious we can refine the numbers.
It is worth saying a few more words on the "faint young sun" myth and try to demystify it.
It is an accepted fact that the pre-life earth had an atmosphere with no free O2, but probably 80% of N2 and 20% of CO2. Early life forms transformed the earth by absorbing the CO2 and turn them into free O2. The ancient biomass was then buried and converted to fossil fuels we burn today.
To explain away why the ancient atmosphere, with 600 times higher CO2 than today's, did not have a run-away GW effect which would have raised the temperature so high that life could not have originated, cosmologists have invented the young faint sun argument. The early sun was too young to radiate at it's full power yet. Combine the weaker solar radiation with the CO2 global warming, the two effects cancel and you get a temperature that's just right for life.
Wrong! The evolution of life happpen at a time scale (a few hundred million years) much shorter than the time scale of stellar evolution (a few billion years).
Also the hypothesis that a young sun would be fainter is also INCORRECT. There's theromal nuclear reaction going on on the sun. The energy is radiated away constantly. The radiation counteracts the gravitational attraction of the sun, and prevents it from colllapsing into even smaller size.
There is a balancing process going on, if the radiation is a bit weaker, then the radiation is not strong enough to counter the gravity, and sun collapse and shrinks a little bit, raising the core temperature and density some what, so the thermo nuclear reactions happen at a higher rate, increasing the radiation, until the radiation can exactly balance off the gravity attraction.
So you see the solar radiation is dedicately balanced at a level no more and no less to balance the gravity of the sun. That's the whole basis of why the sun's radiation is almost constant, regardless whether the sun's age is young or old. Because the sun's mass and gravity pull is virtually constant thoughout its history. The virtual constantness of solar radiation lasts for as long as there is hydrogen fuel left on the sun.
And of course, without that constness of solar radiation, there would not be a comfortable temperature on the earth for life to have originated and evolved.
FYS: the wiki page appears useful: [[Faint young sun paradox]]
Brian - thanks for your comments (sorry I neglected to reply, in the firefight with Lubos/Q). Thanks in particular for the Levitus link - I've added that to the new post.
no, the sun was fainter about 25 percent. 2 b. y ago the co2 content keeped the earth from freezing and in antoher bilion years in the future earth will become very hot and after 3,5 bilion years it will become second Venus.oceans will evaporate..IT IS STELLAR EVOLUTION MORON READ:
"The faint young sun argument is invalid. The life exists on the earth in significant quantity for no more than 200 million years. That is a rather short time period comparing with the evolution of the solar system, which is about 4.6 billion years. For all purposes, on the very first day life was born on earth, the solar system was no longer a young infant, but a fully grown up star system and it has been radiating pretty constantly ever since. The near constness of solar radiation is the whole condition that temperature on earth has always been comfortable for life to have evolved. And indeed the slight fluctuation of solar radiation, is the major reason climate changes over centuries."
:D IDIOT plants and fish were already there 600 mil. yo. ago and bacteria
"1.1 to 3.5 billion years from now
The Sun is growing brighter at a rate of roughly ten percent every billion years. In one billion years time, as the Sun's radiation output increases, its circumstellar habitable zone will move outwards, and the Earth's surface will be seared by solar radiation until it becomes uninhabitable. All life on land will become extinct, though life could still survive in the deeper oceans. Within 3.5 billion years, Earth will attain surface conditions similar to Venus's today; the oceans will boil, and all life (in known forms) will be impossible. During this time this is possible that the surface of Mars will, as its temperature rises, gradually regain its lost atmosphere, as frozen carbon dioxide and water vapour on its surface begin to sublimate. Eventually Mars's surface will reach the temperatures and pressures necessary for its vast frozen reservoirs of water to be unlocked, flooding the land and potentially creating an abode for life for between 1.4 and 2.5 billion years."
if we neglect GW that could happen sooner...
simply, you anti gw arguments are totally wrong
and suns rad. is non constant simplz because of stellar evolution (slow contraction of core to fuse more hydrogen, because its core its slowly depteting its hydrogen and after about 6 by it will became a red giant and roast earth at about 1700 degress celsius
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