1. Depends if you are a dinosaur, or the human race that developed infrastructure in a certain climate regime, or a microbe that can survive a hydrogen sulfide environment (or whatever altered atmosphere different that Holocene pre-industrial).
2. Ask the farmers that are having periodic flooding wipe out their entire crop, and the ones that are losing their crops due to droughts.
3. The question implies that you do not understand the costs – of what might be perceived as a small temperature change. In this case, small/large (0.7C or even as little as 2C) change mean large infrastructure changes. Example: How much will it cost to move the city of Houston and it’s inhabitants (and other cities)?
4. What does this question have to do with climate science?
Dalesays
1. Some questions about AGW:
1. “What is the optimum temperature for life on Earth?”
You might check google.
2. “Won’t a slightly warmer climate be beneficial for agriculture? Given that warmer air holds more moisture?”
Humm, the Central valley of California gets the overwhelming majority of its irragation water from mountain snow pack. Last time I checked that’s decreased by 40% with the prospects that it will continually decrearse. We have over 2.5 billion people who get their water from glaciers. There disapering which will effect people everywhere due to all those people being dislocated. Also, if the grain belt moves north, that means the amount of acres of production will decrease becase the circumferance is less. I’m no expert but I suppose after a huge die off the warmer climate might not be too bad for the survivors but I’m not schooled engough to know.
3. “Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?”
Depends on how many epademics and wars we have to fight. If you ask me, it will be cheaper to be proactive rather than reactive, not to mention that losing the technology race for alternative energy which China, India and Europe mean to win.
4. Did Al Gore really spend $4 million Dollars of his own money on ocean-front property in Florida?
That’s a non sequiter. What does Al Gore’s mailing address have to do with the Earth warming? I don’t think nature gives a damn!
Take the first 64 and the last 64 and find the standard deviation for each. Do a two-tailed F-test for equality between the two figures. Tell me what you find–and which figure is larger.
[Response: Not sure this is quite valid. You would want to be looking at daily numbers at least – and precip values as well as temperatures. Meehl et al (2009) was a good start, as was Alexander et al (2006). – gavin]
Are there any data on annual changes in the global kinetic energy content of winds and ocean currents?
simon abingdonsays
#947 Ray
“the net effect of the clouds must be to do what?”
What do you mean “net” Ray?
Obviously the “contributory” effect of the clouds is to reduce the rate of cooling. At no relevant time is the temperature of the ground rising. The back-radiated IR cannot achieve any net warming effect. Warming of the ground does not take place.
Ray we both know this. We’re just arguing semantics. Gavin will be getting very cross.
[Response: Actually, I don’t care. But other people seem to view you as a teaching moment. I have my doubts. Two questions though: Are you warmer if you use a blanket at night? If you used a blanket for a month would that raise your mean temperature? If your answers are yes and yes, then ta-da! the blanket caused warming. If your answer’s are different, then go away and stop wasting people’s time. – gavin]
As a retired aircraft captain you should know that clear nights are usually colder than cloudy nights. This is exactly the point – clouds keep surface warmer during night.
Gavin has apparently ended the thread. Email me from the link on my site if you actually want to understand this issue. I’ll do what I can.
Dwightsays
Simon, I’m a former English teacher, but of more relevance a gardener in Massachusetts for 35 years. There comes a certain time in autumn when I start to worry about frosts and killing frosts. When I have a cooling afternoon, but it is cloudy, I don’t worry. If it is clear, I unroll the tarps and cover my sensitive plants. Why do you suppose that is?
Simon Rika aka Karmakazesays
I know Gavin asked that the discussion generated by Simon Abingdon end, but I think I see Simon’s (my namesake funnily enough) problem. I think what is happening here is conflicting assumptions of the timescale involved.
Simon seems to be talking about a SINGLE night. So yes, in a single night no new energy is put into the night side of the planet, and it cools. But the people trying to explain to him how this leads to warming have not seemingly explained that they are NOT talking about a single night.
So let me have a quick stab at crossing the barriers with a simple example:
Take a beaker of water and set it on a hotplate that is designed to warm the beaker to 15 deg C but once it reaches that temperature it turns off for a period allowing it to cool to 10 deg C. Then on a cyclic pattern it turns on and off so that the heat lost during the off period balances the heat added during the on period.
You now have a system in equilibirum. Over time, as much energy comes in as goes out.
During any half of the on/off cycle, the energy balance is NOT equal, but as an average of the cycles it is.
Now, create a system that drops a thermal insulation down over the beaker when the element is off, reducing the heat lost during the off phase. Once again, for each off phase, the energy in is zero, but now the energy out is less than before, so the beaker doesn’t cool by 5 deg C anymore, now it cools by say 4 deg C. During this off phase, the beaker still cools, BUT not as much as before, but during the on phase, the beaker heats by the same amount as before.
So during the on phase it increases by 5 deg, during the off it decreases by 4 deg, then during the next on it increases by 5 again. So a simple series of the expected temps:
1D: 15
1N: 10
2D: 15
2N: 11
3D: 16
3N: 12
4D: 17
4N: 13
So on the first day/night on/off cycle temp is raised by 5 and lowered by 5 during the cycle. But on the second, the temp is raised by 5 during the day, but only lowers by 4 during the night. The third day is now starting from a higher temp, and so because it is still heated by 5 degrees, it now reaches a higher temp (16 deg). The next night however it still only goes down by 4 deg, making the temp a degree hotter again, starting the next day a degree hotter and so on.
That is how night time clouds can warm the planet with no extra energy input. By observing over time, you see that the energy out no longer equals energy into the total system, and as such temperature HAS to increase!
Does that make things a bit clearer for you Simon?
–
On another subject, I can’t help noticing all the calls for more transparency that have dramatically increased since the CRU emails surfaced.
I would like to ask anyone, denier or realist alike; has anyone heard of a field of science that is THIS open to the general public?
Are the data and source codes for the LHC for example available to the general public right now? If not why are these “transparency in science” types not demanding that?
Seriously, is there any other field of science at all that has this much public availability of the data etc, and this much participation by the general public? How many builders involve themselves in dicussions of black holes? Or cancer treatments. In fact who in the general public would dare to go to cancer research doctors and tell them they’re doing it wrong?
I find it astounding that anyone could think climate science is less transparent than any other field of science, and less open to the general public’s concerns.
TRYsays
Fascinating stuff.
BPL – do you have references for the successful model predictions you note? In the papers I’ve read, models are used to validate or correct measurements and statistical approaches. I’m not asking for an explanation or anything like that – just requesting links to the source material that underlies the post.
Ray – All of this goes back, ultimately, to the effect of an increase in CO2 and other gases in the atmosphere. That’s where the really interesting discussions happen, I think – less argument about which statistical approach, which measurements to use, etc, etc. And claims on both sides seem testable. Would enjoy your thoughts on these items:
We assume land and sea radiate blackbody radiation that’s entirely determined by their surface temperature? – this seems reasonable and expected.
We assume CO2 absorbs photons of certain wavelengths – tested and known.
How does CO2 radiate that input energy? I’ve seen people claim that a CO2 molecule will absorb the specific IR wavelengths, then radiate like a blackbody, and others clailm that the CO2 molecule will radiate the same wavelengths it absorbs. Easy to test I’m sure – just radiate a chamber full of CO2 with these wavelengths and see what wavelenghts come back to you, right?
Back to our planet as a whole, the only source of energy is radiation from the sun. So to heat the planet, but with not change in solar radiation, you’re going to see an imbalance in radiation as the planet warms. If that imbalance is due to absorption in specific IR wavelenghts, when you look at outbound radiation, you’re going to see drops in those wavelengths, and increases in other IR wavelengths – because any increase in global temperature is going to increase the blackbody radiation. Total output energy will be lower than before, but you will see increases in certain wavelenghts and declines in others. Assuming equilibrium is reached, total in and out will again be equal, but the radiation ‘signature’ will be different than at the last equilibrium.
Are there any studies or analysis that show this? The one at skepticalscience shows a total decline in radiation at all wavelengths, impling global cooling if taken at face valie.
Back to lookin at seasonal changes or short term changes, you suggest that we must look at hemispheres separately, presumably because seasonal changes in CO2 cancel eachother out? But there’s so much more land/plant mass in the N. hemisphere, I’d assume that global CO2 does change seasonally by a measurable amount. Is this really that hard to do? A number of people have named satellites with IR sensors.
Garry Grams:
1. What is the optimum temperature for life on Earth?
BPL: The exquisitely stable one our agriculture and economy have adapted to over the past thousand years or so. About 287-288 K (14-15 C, 57-59 F).
2. Won’t a slightly warmer climate be beneficial for agriculture? Given that warmer air holds more moisture?
BPL: No, because it will be distributed differently. In 1970, 12% of the Earth’s land surface was “severely dry” by the Palmer Drought Severity Index. By 2002 that figure was 30%. There is more precipitation, but less of it is in continental interiors and more along coastlines.
3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?
BPL: Not if our agriculture collapses and most of us die.
4. Did Al Gore really spend $4 million Dollars of his own money on ocean-front property in Florida?
BPL: Who the bleeding heck cares? If Al Gore tortures puppies in his basement, it has nothing to do with whether what he’s saying is accurate or not. A chain-smoking doctor who tells you you’re going to die if you quit smoking is still telling you the truth.
Rod Bsays
Hank (866), a minor point but I think the ideal roof paint, to keep things cool, would reflect the visible and be a good emitter (low reflectivity) of infrared.
Ron R.says
Timothy Chase #940, yes but the culture of the anesthesia of forgetting recapitulates the denomination of normative value(s) don’t you think? I mean, the poetics of binary opposition replays (in parodic form) the ideology of classification right?
And after all the differentiation of the hidden fosters the figuralization of the materialist architectonic. Now if we were to say that the illusion of paratextual apparatus gestures toward the experience of the eclectic then surely we can infer that the imposition of autonomous phenomena specifies the fundamental principle of history as such. Wouldn’t you agree?
Now in this context we could say that the imposition of self-referential systems revisits the authentication of humanist organicism but the renunciation of factual knowledge may be regarded as the project of unsituated knowledge. Personally, though I think that the poetics of paratextual apparatus is comparable with the denomination of power because the invention of the literary canon reaffirms the totalization of enlightenment rationalism because the phenomenalism of narrative sequence fails to penetrate the myths obscuring the affirmation of syntactical certainty. But then again the discourse of panopticism is strictly congruent with the desacrilization of the Other.
Garry Grams (from 945), let me try to answer the first three questions, which are good ones. I will not touch the last one.
1) What is the optimum temperature for which kind of life? It is possible that a 3 degree warmer planet could support more bio-diversity, or simply more biomass, but there is no clear answer for this. It may not be so good for human agriculture, which is mainly derived from temperate climates. Even if such a climate is OK for us (and it may well not be), the transition to such a climate will definitely be difficult. I do not think abandoning the climate that human civilization was created in and is adapted to is a very good idea, and should be avoided as much as possible. That is called being conservative.
2) A warmer climate will benefit agriculture in cooler areas, as long as there is also sufficient moisture. While a warmer climate means more precipitation, it also means more evaporation. Useful moisture is the difference between the two, and models predict a slight net decrease in available moisture. But note that grains are derived from a moderate climate, and are already growing at the limit of their temperature range. In already warm parts of the world, warmer climate means reduced productivity. Also a warmer climate will shift climate zones, so some areas that are productive today will become deserts. This is a complex question, but so far it appears the overall answer is no, this is not something we want to happen. It is a cost, not a benefit.
3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate? This is the hardest question of all, because it involves trading off present benefits of fossil fuel consumption against uncertain but possibly severe consequences in the future. It is also a question of values. For example, what value do we place on the very likely consequence of sea level rising by five or ten meters, but a few hundred years in the future? This is not a crazy scare story, our knowledge of past climates shows that the size of the ice caps, which hold the potential of 70 meters of sea level rise, are very sensitive to temperature. During the ice age, which was about 5 degrees C colder, sea level was 120 meters lower than today.
The answer is we should be doing more to reduce carbon dioxide emissions than we are today. But the more we reduce, the more expensive it becomes. If we cut emissions to zero, civilization collapses. So how much reduction is the optimum is hard to say, but we are well below that optimum today.
CMsays
Garry Grams asked,
> 1. What is the optimum temperature for life on Earth?
Different species/habitats, different optima, many of which fall somewhere above the freezing point of water and below its boiling point.
Seriously, though, a lot of people have been posing similar questions here lately. Would you mind telling us where you picked up the idea that this is a relevant question for the global warming debate? It really isn’t, you see.
We don’t have the luxury of managing the planet for some optimal temperature. We are talking about a sharp temperature rise probably unparalleled in human history, and about what belated and messy action we can take to contain it so it doesn’t get really dangerous.
> 2. Won’t a slightly warmer climate be beneficial for agriculture?
In some places, and combined with more CO2 in the air, probably yes for a *slightly* warmer climate, as long as a number of hard-to-predict local and regional impacts (drought, flooding, harvest-destroying extreme weather events) don’t come into play. In other places, probably no; even a slight global warming (anything over 1°C) is expected to harm agriculture in Africa. The latest IPCC report expects total world food production to decline for a rise above 3°C, and under present policies, that’s sadly likely to happen.
> 3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?
We’ll have to do adaptation anyway. But no, that doesn’t mean it’s cheaper to just let things slide. The 2006 Stern review, for one, found the costs of action to limit emissions considerably lower than the costs of inaction.
You may want to read Mark Lynas’s book, _Six Degrees_, and consider how you’d imagine adapting to some of the impacts described there for warming above 2°C. It’s not just about everything gradually getting a little hotter. It’s about crossing thresholds to dramatic, irreversible changes, like wiping out coral reefs.
My two cents: it’s a decision about what risks to take with the whole planet over the next centuries, so it calls more for moral wisdom and common-sense prudence than for financial smarts. Your question is a little bit like asking, “Instead of spending time and money on getting a healthy diet and plenty of exercise for myself and my family, wouldn’t I be better off saving up money for our coronary disease treatments?” – if you think about making that decision for your children and grandchildren as well.
Looks like my earlier comment on “Garry” and his “What is the optimum temperature for life on Earth?” got wiped out for snarkiness. But this exact question, almost same phrase, was asked earlier (#556) by “Ken Rogers”, responded to by Gavin, and then by me (#564). And yet, here we are again. Is it question of the day on WUWT perhaps? Do these people ever read the replies to exactly the same question asked by others of their ilk?
CMsays
Correction: I omitted a couple of important qualifications from my IPCC reference at ~969:
“These results, on the whole, project the *potential* for global food production to increase with increases in *local* average temperature over a range of 1 to 3ºC, but above this range to decrease.” (IPCC 2007, WG2, ch. 5, p. 275)
Leo Gsays
Ray L @ 902
could you please answer this for me. From my understanding, the growth in overall CO2 is both from fossil fuel burning and natural reaction to the raising temps. What percentage of this growth is from FF burning? From what I have been able to find out elsewhere, it seems the FF burning is less then half of the total of the “new” CO2.
Why i ask is because you stated that if we halved the present amount of CO2 in the atmosphere, we may see a decline of up to 3*C. But if the amount of CO2 being “put” into the atmosphere by FF burning is less then would accomplish that, then how can we get to that halving point?
Thanx for your time.
AlCsays
#963 TRY
To answer the question in your last paragraph about CO2 seasonal variability in the Northern Hemisphere, see:
I find this plot to have a certain majesty, showing the planet breathing during the course of a year. Unfortunately, it also shows the trend of carbon dioxide concentration is inexorably upward.
As you suspected, Southern Hemisphere plots show less carbon dioxide uptake during the growing season.
These measurements are not easy to make accurately. In one recent presentation, the speaker said that at least 20% of their effort was spent on Quality Assurance, making sure that their data was accurate, checking against standards, etc.
There was supposed to be a satellite to measure CO2 concentrations (OCO), but there was a problem with the rocket, and it fell into the ocean.
Perhaps others can speak to whether there is a satellite continually monitoring IR spectra from Earth.
David B. Bensonsays
David Horton (971) — There are avid thread readers and there are those who don’t bother.
Ray Ladburysays
Well, Simon, I’m cured. I realize that you are now a troll. Your posts will now be ignored entirely by me. You are merely regurgitating what you have read in G&T, which has been shown to be not only wrong but ludicrous. Is it your contention that infrared radiation reflected from clouds cannot be absorbed by the ground, or is it your contention that infrared radiation absorbed by the ground will miraculously not warm it if it comes from clouds. Either way, sod off, clown!
Leo Gsays
Gavin, maybe a discussion on this NASA paper, purporting that CO2 is not well mixed in the trophosphere, “but rather lumpy” could be interesting.
> question of the day
Bots, I tell you. Put in a keyword like +warmist to filter and try it:
Results … about 3,490 for
optimum temperature for life on Earth climate +warmist
Ray Ladburysays
TRY, your first 3 points all have to do with absorption and emission of radiation. In such a discussion, it is helpful to think of an ideal absorber/radiator–a black body. Earth is not such a body–either over sea over land, but it’s a reasonable approximation to a gray body, when averaged over the surface–that is it absorbs/radiates a spectrum that is reasonably blackbody-shaped, but has some irregularities. We know in great detail what this spectrum looks like.
WRT CO2, it can only emit in the “lines” where it can absorb. There’s no addiational “blackbody” spectrum. Remember, however, that the “lines” get distorted by collisions, pressure, etc. We are talking about the energy levels of an oscillator. You can see, even semi-classically how distorting the atomic structure in a collision could change those slightly, right?
As to the planet, I guess you missed the beautiful figure Gavin had showing both heating of the troposphere and cooling of the stratosphere–right where you’d expect in, both in terms of wavelength and altitude. Here it is again–truly a gorgeous figure: http://www.atmosphere.mpg.de/media/archive/1460.jpg
Here’s the thing, though. The sort of measurement you want to make is not a trivial one. Sure we can take a satellite picture or measurements, but it is just a snapshot. That’s not enough. We already know that short-term variability can dominate the signal due to CO2 on a timescale of a year of two, or even a few years. So, we need to know the solar energy coming in and being reflected out, and we need to be able to measure the IR radiation out. We need to be able to do this over a period of several years. What we are really talking about is a fleet of satellites if we want to answer this definitively, and that means we have to be able to process and calibrate data across instruments over the life of the mission. It’s not an easy measurement to get a 100% definitive answer beyond the 95-99% answers we already have.
Ladbury’s third law of reliability: ‘1’ may be the loneliest number, but ‘9’s and ‘0’s are the most expensive.
Ray Ladburysays
Rod B. @965, remember that you are trying to increase planetary albedo to sunlight, not stop warming due to backradiation. As such, the relevant spectral range is the visible.
Steve Fishsays
Comment by Ron R. — 27 December 2009 @ 4:16 PM:
Thanks for that. You have found the perfect academic to discuss climate mechanisms with Simon Abingdon on an equal basis.
[Response: the daily mail is not a reliable source. -gavin]
Brian Rookardsays
Dhogaza says: “Well, climate science doesn’t support the notion of a ‘runaway greenhouse effect’ (ala venus or whatever), so perhaps it is better to focus on what climate science *is* telling us.”
Well, James Hansen would appear to disagree with you:
Maybe you should point out to James Hansen that “climate science doesn’t support the notion of a ‘runaway greenhouse effect’.”
Geoff Wexlersays
re: #963 ; para.5.
“I’ve seen people claim that a CO2 molecule will absorb the specific IR wavelengths, then radiate like a blackbody, and others clailm that the CO2 molecule will radiate the same wavelengths it absorbs”
The ‘others’ have it in this case. The black body claim you mention is wrong, because it disregards the emissivity coefficient which varies strongly with wavelength for CO2. The claim by the others rests on the law that the emissivity is equal to the absorptivity at thermal equilbrium.
If you want to consider black body behaviour for infra-red, consider solids and liquids rather than absorbing gases. These tend to absorb nearly all incoming infra-red irrespective of wavelength i.e they are ‘black’ for infra-red even though they may be coloured for visible light.
Ljubisa Cvetkovicsays
Ray wrote:
No, forcing is the energy the component adds to the system, and so for CO2, it increases logarithmically with concentration. The best guess is that if we double CO2 we add 3 degrees per doubling, so if we halved CO2 content (not the increase, the content), we’d drop 3 degrees on average.
The “START HERE” has several introductory treatments of the greenhouse effect. I recommend them.
Yes, that’s what I meant. The thing is, annual emissions are 1.5% of the content now, but the content is not rising by 1.5%, but by a lesser percent. This means the excess CO2 goes somewhere, to the oceans, into the plants, etc…
Thanks for correcting my calculation, yes, doubling by 2054.
Once emissions fall enough, let’s say to half the present amount (likely by 2045), and given that sinks will be increased, in spite of our emissions, CO2 content starts decreasing. Are we then facing cooling for the coming years (beyond 2050)? If so, we need to be careful not to overdo it.
By the way, coal plants also emit aerosols. Do they have a net warming or net cooling effect? I know you dislike aerosols, but we might just be in a situation where we have to choose between aerosols and warming.
We also need to be sure of the net effect of forests and other major factors, so we could fine tune them if need be.
We also need to consider that fossil fuels are a finite resource, so even if we don’t reduce emissions by law, they are sure to decrease through economic need because the fossil fuel energy source will become more and more expensive, while alternatives will become less and less expensive eventually overtaking fossil fuels, and from that point on, there’s no turning back.
Ray Ladburysays
Leo G., where is this “natural” CO2 supposed to be coming from? Right now, the oceans are still a sink for CO2, and we haven’t really triggered melting permafrosts or clathrates just yet. There is also contribution from land use, cement production, etc. It is true that the carbon cycle itself has huge fluxes of “natural” carbon, but the isotopic signature of the added CO2 shows it has a very large fossil (and therefore anthropogenic) component.
Prof T Heidricksays
Is anybody aware of any paper/thesis etc where a simple heat calculation has been published. Several hundred years ago the only heat we produced was from fires here and there and a relatively few people. Now, we have more people and everything we do produces heat (even cars braking produce heat) Solar-electricity-eventually turns into hear. Wind , Nuclear, fossil it all does. Has anyone seen a publication where people simply looked a heat generation on our sphere 100 years ago and now even with a constant atmosphere. Does it matter if it is fossil fuels (GHG won;t help but is it the root cause)or was solar, nuclear etc. If I had a soccer ball with some metal in it so I could inductively heat it, the temperature of nearby air before I did would be lower than after. The same would be true if I burned it.
Has anyone seen such a simple analysis?
[Response: You can do it yourself. Look up total energy use and then convert it into an energy flux at the surface and then compare to the radiative forcing from CO2. It’s a good exercise in quantitative thinking. – gavin]
“Most high-albedo surfaces are light-colored, although selective surfaces which reflect a large portion of the infrared solar radiation, but which absorb some visible light, may be dark colored, yet have relatively high albedos.”
“Forty-five percent of the total solar energy is in the non-visible infrared region….
… Infrared reflective inorganic pigments are complex inorganic color pigments, which reflect the wavelengths in infrared region in addition to reflecting some visible light selectively….”
So, nope, you can, by the time you need to repaint your roof next time around, probably get any color or combination of colors you want, and likely can get metal-clad or shingle material that will be selective.
And some folks are working on materials that will change from absorbing to rejecting heat depending on whether you want to warm or cool the house.
Norbertsays
I think a serious mistake in Simon Abingdon’s argument is the assumption that there is a night time and a day time. That sounds like a flat earth assumption. In reality, the planet is round and always about half of it is towards the sun, and about the other half is away from the sun. The half which is away from the sun gets warmed by the rotation of the planet. Energy is always added on the sun side, and always lost on the dark side. Without the atmosphere and the clouds on the dark side, the rotation of the planet wouldn’t be able to warm the dark side.
Therefore the atmosphere and the clouds are a necessary element for the rotation of the planet to warm the dark side.
Ron R.says
Steve Fish #981, Actually the disintegration of communicative interaction gestures toward the culture of the public sphere.
Er, it speaks skeptic language too. I.E. If you can’t dazzle ’em with brilliance…
Note: not you Timothy, just funning you Bro. :-)
dhogazasays
Leo G
could you please answer this for me. From my understanding, the growth in overall CO2 is both from fossil fuel burning and natural reaction to the raising temps. What percentage of this growth is from FF burning? From what I have been able to find out elsewhere, it seems the FF burning is less then half of the total of the “new” CO2.
I’m not Ray but … you’ve probably misunderstood something you’ve read (or, perhaps, have been lied to).
Generally the “natural reaction to the raising temps” refers to oceans outgassing CO2 as they warm. This happens if they’re in equilibrium with the atmosphere when warming begins, for instance as the earth begins to emerge from ice ages. The warming kicks the system out of equilibrium, leading to outgassing. They become a CO2 source.
However, if the oceans are in equilibrium with the atmosphere, and then you start pouring massive amounts of CO2 into the atmosphere – for instance, by burning massive amounts of fossil fuels – things are no longer in equilibrium, but this time it’s due to there being so much CO2 in the atmosphere. The oceans absorb CO2. Yes, they also warm, but if enough CO2 is continuously poured into the atmosphere, not fast enough for the oceans to saturate thus they continue to absorb CO2. They are a sink, not source, under this scenario.
(I’m simplifying, since there’s continuous exchange of gasses between the oceans and atmosphere so sink vs. source refers to the net balance if the exchange, and I’m ignoring the fact that the situation slowly changes as the oceans warm.)
The 50% figure you refer to *probably* something you’ve read backwards (or your source has read backwards).
It’s not that only 50% of the excess CO2 we’re seeing comes from fossil fuel burning.
It’s that CO2 concentrations in the atmosphere are only growing roughly 50% as fast as we pour CO2 into the atmosphere, with the oceans (mostly) absorbing the other 50%. That slows warming, but is having serious effects on ocean chemistry – the “ocean acidification” problem you may’ve heard about.
We had to endure mad max manacker with his claims about cyclicity, backed up by all the rigor of “Looks pretty cyclical to me.” Then we were assaulted by Matthew and his regurgitation of the “trend change in 1998” garbage. Then we had that stuff about “daggers to the heart” of AGW. And now Bruce Williams invents a fantasy about “SUSTAINED” increased in the GISS temperature record.
These crackpots have had their say. In fact they’ve had way more than their fair share of say. Enough is enough. Having to endure the same crap over and over again has made the comment threads worse than useless — they’re actually counterproductive.
I reiterate my suggestion: stand up for sanity by using the “delete” button often, or simply close threads to comments altogether. Yeah that would be bad, but still better than letting crackpots ruin the blog.
Prof T Heidricksays
HI Gavin
Of course I could do it myself…but science moves buiding on each others work. There is no sense re-inventing any wheel. I am a Prof and could have grad students do this…but if it has already been done what is the point. I repeat..has anybody seen this. If so we can build on it, putting in various assumptions on the environment rather than re-do it. We want to add to existing knowledge, not re-invent it.
TH
[Response: It’s trivial. See here for a worked out example. – gavin]
Don’t argue with conclusory statements; citations are much less likely to run off into endless exchanges of beliefs.
Dwightsays
Tamino, You obviously know exponentially more about climate change than I do, but you are too damned sensitive to noise. Have you ever been a teacher? You don’t always get “nice” questions. I, for one, can learn a lot by hearing people respond to what you, undoubtedly, think are crackpot or even malicious ideas.
Maybe the believer-scientific choir all singing together would produce beautiful music…but would anyone be listening? If you guys can cut through the noise of weather and keep your eye on climate, you (undoubtedly precise, focused, and orderly scientific types), at least hypothetically, should also be able to deal better with human noise. Good grief, it is what humans do.
Now to reveal more of my own ignorance, in those links to your site where you showed the ten year temperatures in order to demonstrate that there had NOT been cooling, what does the anomalie column represent or mean?
David Wrightsays
“I reiterate my suggestion: stand up for sanity by using the “delete” button often, or simply close threads to comments altogether. Yeah that would be bad, but still better than letting crackpots ruin the blog.”
Apparently the reality of the CRU expose’ has not sunk in.
Leo Gsays
dhogaza, thanx for that.
So let’s say, (very simply) in a perfect world, over the next 20-30 years, we basically stop all burning of FF for energy, and the CO2 content in the atmosphere is now above 400 PPM, how do we get to halving that amount? Will the CO2 sinks keep on absorbing? or are they now at equilibrium to their new state?
Or is there a natural tendency for the atmosphere to re-align itself to the 250-300 PPM?
I guess what I am trying to understand, is if we even get to a point where the net increase of CO2 in the atmosphere is finally stopped, is mankind going to be able to lower it back to a safer level? or do we have to adapt to a new reality?
Given the interesting discussion between Blair Dowden and Timothy Chase about snowball earth and the possibility of a runaway greenhouse and that fact both these “educated lay” commenter’s are probably stretching the limits of their own knowledge, perhaps these would be good topics for some future posts?
Having a look at Hansen’s 2008 Bjerknes lecture, it is clear that the possibility of a runaway greenhouse is his personal opinion, given the increase in solar irradiance since the last time C02 was extremely high and the “unprecedented speed of positive forcing”.
Searching back through RC I couldn’t find any posts on this area, apart from an inline comment from Raypierre back in 05 where he stated a runaway greenhouse was extremely unlikely.
A post expanding on and, (if possible) explaining the reasons for the contrasting views of Hansen and others such as Ray on this area would be really interesting.
My first reaction was to try and rapidly decipher what you were writing. Failing that and realizing that I would have to read it rather closely but not being in quite the right mood for that sort of thing (I just got back from taking photos for some panoramas — but where I was fighting the sun rather than having it work for me), I decided to try and classify it. The best I could come up with was existentialism or deconstructionism. Unfortunately it was reminding me more of deconstructionism than existentialism — and of strong deconstructionism at that.
Really not my cup of tea.
Then I realized that your questions suggested that you didn’t have any better a handle on what you had posted than I did, and at that point I thought plagiarism. Oddly enough, it was at that point that I started to feel more warmly towards you. But I wanted to know where you were getting you text, so I started putting fragments into Google but without quotes. Paul de Mann. Herbert Marcuse. But only words and phrases were coming up. No complete sentences. “Typing something out of a book?,” I wondered.
How can you slow down an airliner from 500 knots to 400 knots when 400 knots is very fast indeed …
Shouldn’t y’all be saying “Permission to less fast to 400 knots, please”?
Just to be consistent with your claiming that less cooling can’t be warming …
#945 Garry Grams
1. Depends if you are a dinosaur, or the human race that developed infrastructure in a certain climate regime, or a microbe that can survive a hydrogen sulfide environment (or whatever altered atmosphere different that Holocene pre-industrial).
2. Ask the farmers that are having periodic flooding wipe out their entire crop, and the ones that are losing their crops due to droughts.
3. The question implies that you do not understand the costs – of what might be perceived as a small temperature change. In this case, small/large (0.7C or even as little as 2C) change mean large infrastructure changes. Example: How much will it cost to move the city of Houston and it’s inhabitants (and other cities)?
4. What does this question have to do with climate science?
1. Some questions about AGW:
1. “What is the optimum temperature for life on Earth?”
You might check google.
2. “Won’t a slightly warmer climate be beneficial for agriculture? Given that warmer air holds more moisture?”
Humm, the Central valley of California gets the overwhelming majority of its irragation water from mountain snow pack. Last time I checked that’s decreased by 40% with the prospects that it will continually decrearse. We have over 2.5 billion people who get their water from glaciers. There disapering which will effect people everywhere due to all those people being dislocated. Also, if the grain belt moves north, that means the amount of acres of production will decrease becase the circumferance is less. I’m no expert but I suppose after a huge die off the warmer climate might not be too bad for the survivors but I’m not schooled engough to know.
3. “Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?”
Depends on how many epademics and wars we have to fight. If you ask me, it will be cheaper to be proactive rather than reactive, not to mention that losing the technology race for alternative energy which China, India and Europe mean to win.
4. Did Al Gore really spend $4 million Dollars of his own money on ocean-front property in Florida?
That’s a non sequiter. What does Al Gore’s mailing address have to do with the Earth warming? I don’t think nature gives a damn!
Ljuvisa Cvetkovic: There is only occasional correlation between CO2 and temperature trends
BPL: Look again:
http://BartonPaulLevenson.com/Correlation.html
Norman: Do any have valid evidence that the weather has become more extreme in the last couple of decades?
BPL: I have 128 years of annual NASA GISS global temperature anomalies here:
http://BartonPaulLevenson.com/Correlation.html
Take the first 64 and the last 64 and find the standard deviation for each. Do a two-tailed F-test for equality between the two figures. Tell me what you find–and which figure is larger.
[Response: Not sure this is quite valid. You would want to be looking at daily numbers at least – and precip values as well as temperatures. Meehl et al (2009) was a good start, as was Alexander et al (2006). – gavin]
Are there any data on annual changes in the global kinetic energy content of winds and ocean currents?
#947 Ray
“the net effect of the clouds must be to do what?”
What do you mean “net” Ray?
Obviously the “contributory” effect of the clouds is to reduce the rate of cooling. At no relevant time is the temperature of the ground rising. The back-radiated IR cannot achieve any net warming effect. Warming of the ground does not take place.
Ray we both know this. We’re just arguing semantics. Gavin will be getting very cross.
[Response: Actually, I don’t care. But other people seem to view you as a teaching moment. I have my doubts. Two questions though: Are you warmer if you use a blanket at night? If you used a blanket for a month would that raise your mean temperature? If your answers are yes and yes, then ta-da! the blanket caused warming. If your answer’s are different, then go away and stop wasting people’s time. – gavin]
Ljubisa Cvetkovic — I encourage reding “The Discovery of Global Warming” by Spencer Weart:
http://www.aip.org/history/climate/index.html
#944 Simon Abington
As a retired aircraft captain you should know that clear nights are usually colder than cloudy nights. This is exactly the point – clouds keep surface warmer during night.
simon,
Gavin has apparently ended the thread. Email me from the link on my site if you actually want to understand this issue. I’ll do what I can.
Simon, I’m a former English teacher, but of more relevance a gardener in Massachusetts for 35 years. There comes a certain time in autumn when I start to worry about frosts and killing frosts. When I have a cooling afternoon, but it is cloudy, I don’t worry. If it is clear, I unroll the tarps and cover my sensitive plants. Why do you suppose that is?
I know Gavin asked that the discussion generated by Simon Abingdon end, but I think I see Simon’s (my namesake funnily enough) problem. I think what is happening here is conflicting assumptions of the timescale involved.
Simon seems to be talking about a SINGLE night. So yes, in a single night no new energy is put into the night side of the planet, and it cools. But the people trying to explain to him how this leads to warming have not seemingly explained that they are NOT talking about a single night.
So let me have a quick stab at crossing the barriers with a simple example:
Take a beaker of water and set it on a hotplate that is designed to warm the beaker to 15 deg C but once it reaches that temperature it turns off for a period allowing it to cool to 10 deg C. Then on a cyclic pattern it turns on and off so that the heat lost during the off period balances the heat added during the on period.
You now have a system in equilibirum. Over time, as much energy comes in as goes out.
During any half of the on/off cycle, the energy balance is NOT equal, but as an average of the cycles it is.
Now, create a system that drops a thermal insulation down over the beaker when the element is off, reducing the heat lost during the off phase. Once again, for each off phase, the energy in is zero, but now the energy out is less than before, so the beaker doesn’t cool by 5 deg C anymore, now it cools by say 4 deg C. During this off phase, the beaker still cools, BUT not as much as before, but during the on phase, the beaker heats by the same amount as before.
So during the on phase it increases by 5 deg, during the off it decreases by 4 deg, then during the next on it increases by 5 again. So a simple series of the expected temps:
1D: 15
1N: 10
2D: 15
2N: 11
3D: 16
3N: 12
4D: 17
4N: 13
So on the first day/night on/off cycle temp is raised by 5 and lowered by 5 during the cycle. But on the second, the temp is raised by 5 during the day, but only lowers by 4 during the night. The third day is now starting from a higher temp, and so because it is still heated by 5 degrees, it now reaches a higher temp (16 deg). The next night however it still only goes down by 4 deg, making the temp a degree hotter again, starting the next day a degree hotter and so on.
That is how night time clouds can warm the planet with no extra energy input. By observing over time, you see that the energy out no longer equals energy into the total system, and as such temperature HAS to increase!
Does that make things a bit clearer for you Simon?
–
On another subject, I can’t help noticing all the calls for more transparency that have dramatically increased since the CRU emails surfaced.
I would like to ask anyone, denier or realist alike; has anyone heard of a field of science that is THIS open to the general public?
Are the data and source codes for the LHC for example available to the general public right now? If not why are these “transparency in science” types not demanding that?
Seriously, is there any other field of science at all that has this much public availability of the data etc, and this much participation by the general public? How many builders involve themselves in dicussions of black holes? Or cancer treatments. In fact who in the general public would dare to go to cancer research doctors and tell them they’re doing it wrong?
I find it astounding that anyone could think climate science is less transparent than any other field of science, and less open to the general public’s concerns.
Fascinating stuff.
BPL – do you have references for the successful model predictions you note? In the papers I’ve read, models are used to validate or correct measurements and statistical approaches. I’m not asking for an explanation or anything like that – just requesting links to the source material that underlies the post.
Ray – All of this goes back, ultimately, to the effect of an increase in CO2 and other gases in the atmosphere. That’s where the really interesting discussions happen, I think – less argument about which statistical approach, which measurements to use, etc, etc. And claims on both sides seem testable. Would enjoy your thoughts on these items:
We assume land and sea radiate blackbody radiation that’s entirely determined by their surface temperature? – this seems reasonable and expected.
We assume CO2 absorbs photons of certain wavelengths – tested and known.
How does CO2 radiate that input energy? I’ve seen people claim that a CO2 molecule will absorb the specific IR wavelengths, then radiate like a blackbody, and others clailm that the CO2 molecule will radiate the same wavelengths it absorbs. Easy to test I’m sure – just radiate a chamber full of CO2 with these wavelengths and see what wavelenghts come back to you, right?
Back to our planet as a whole, the only source of energy is radiation from the sun. So to heat the planet, but with not change in solar radiation, you’re going to see an imbalance in radiation as the planet warms. If that imbalance is due to absorption in specific IR wavelenghts, when you look at outbound radiation, you’re going to see drops in those wavelengths, and increases in other IR wavelengths – because any increase in global temperature is going to increase the blackbody radiation. Total output energy will be lower than before, but you will see increases in certain wavelenghts and declines in others. Assuming equilibrium is reached, total in and out will again be equal, but the radiation ‘signature’ will be different than at the last equilibrium.
Are there any studies or analysis that show this? The one at skepticalscience shows a total decline in radiation at all wavelengths, impling global cooling if taken at face valie.
Back to lookin at seasonal changes or short term changes, you suggest that we must look at hemispheres separately, presumably because seasonal changes in CO2 cancel eachother out? But there’s so much more land/plant mass in the N. hemisphere, I’d assume that global CO2 does change seasonally by a measurable amount. Is this really that hard to do? A number of people have named satellites with IR sensors.
Garry Grams:
1. What is the optimum temperature for life on Earth?
BPL: The exquisitely stable one our agriculture and economy have adapted to over the past thousand years or so. About 287-288 K (14-15 C, 57-59 F).
2. Won’t a slightly warmer climate be beneficial for agriculture? Given that warmer air holds more moisture?
BPL: No, because it will be distributed differently. In 1970, 12% of the Earth’s land surface was “severely dry” by the Palmer Drought Severity Index. By 2002 that figure was 30%. There is more precipitation, but less of it is in continental interiors and more along coastlines.
3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?
BPL: Not if our agriculture collapses and most of us die.
4. Did Al Gore really spend $4 million Dollars of his own money on ocean-front property in Florida?
BPL: Who the bleeding heck cares? If Al Gore tortures puppies in his basement, it has nothing to do with whether what he’s saying is accurate or not. A chain-smoking doctor who tells you you’re going to die if you quit smoking is still telling you the truth.
Hank (866), a minor point but I think the ideal roof paint, to keep things cool, would reflect the visible and be a good emitter (low reflectivity) of infrared.
Timothy Chase #940, yes but the culture of the anesthesia of forgetting recapitulates the denomination of normative value(s) don’t you think? I mean, the poetics of binary opposition replays (in parodic form) the ideology of classification right?
And after all the differentiation of the hidden fosters the figuralization of the materialist architectonic. Now if we were to say that the illusion of paratextual apparatus gestures toward the experience of the eclectic then surely we can infer that the imposition of autonomous phenomena specifies the fundamental principle of history as such. Wouldn’t you agree?
Now in this context we could say that the imposition of self-referential systems revisits the authentication of humanist organicism but the renunciation of factual knowledge may be regarded as the project of unsituated knowledge. Personally, though I think that the poetics of paratextual apparatus is comparable with the denomination of power because the invention of the literary canon reaffirms the totalization of enlightenment rationalism because the phenomenalism of narrative sequence fails to penetrate the myths obscuring the affirmation of syntactical certainty. But then again the discourse of panopticism is strictly congruent with the desacrilization of the Other.
I could be wrong here. What do you think?
http://tinyurl.com/e8bwf
Garry Grams (from 945), let me try to answer the first three questions, which are good ones. I will not touch the last one.
1) What is the optimum temperature for which kind of life? It is possible that a 3 degree warmer planet could support more bio-diversity, or simply more biomass, but there is no clear answer for this. It may not be so good for human agriculture, which is mainly derived from temperate climates. Even if such a climate is OK for us (and it may well not be), the transition to such a climate will definitely be difficult. I do not think abandoning the climate that human civilization was created in and is adapted to is a very good idea, and should be avoided as much as possible. That is called being conservative.
2) A warmer climate will benefit agriculture in cooler areas, as long as there is also sufficient moisture. While a warmer climate means more precipitation, it also means more evaporation. Useful moisture is the difference between the two, and models predict a slight net decrease in available moisture. But note that grains are derived from a moderate climate, and are already growing at the limit of their temperature range. In already warm parts of the world, warmer climate means reduced productivity. Also a warmer climate will shift climate zones, so some areas that are productive today will become deserts. This is a complex question, but so far it appears the overall answer is no, this is not something we want to happen. It is a cost, not a benefit.
3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate? This is the hardest question of all, because it involves trading off present benefits of fossil fuel consumption against uncertain but possibly severe consequences in the future. It is also a question of values. For example, what value do we place on the very likely consequence of sea level rising by five or ten meters, but a few hundred years in the future? This is not a crazy scare story, our knowledge of past climates shows that the size of the ice caps, which hold the potential of 70 meters of sea level rise, are very sensitive to temperature. During the ice age, which was about 5 degrees C colder, sea level was 120 meters lower than today.
The answer is we should be doing more to reduce carbon dioxide emissions than we are today. But the more we reduce, the more expensive it becomes. If we cut emissions to zero, civilization collapses. So how much reduction is the optimum is hard to say, but we are well below that optimum today.
Garry Grams asked,
> 1. What is the optimum temperature for life on Earth?
Different species/habitats, different optima, many of which fall somewhere above the freezing point of water and below its boiling point.
Seriously, though, a lot of people have been posing similar questions here lately. Would you mind telling us where you picked up the idea that this is a relevant question for the global warming debate? It really isn’t, you see.
We don’t have the luxury of managing the planet for some optimal temperature. We are talking about a sharp temperature rise probably unparalleled in human history, and about what belated and messy action we can take to contain it so it doesn’t get really dangerous.
> 2. Won’t a slightly warmer climate be beneficial for agriculture?
In some places, and combined with more CO2 in the air, probably yes for a *slightly* warmer climate, as long as a number of hard-to-predict local and regional impacts (drought, flooding, harvest-destroying extreme weather events) don’t come into play. In other places, probably no; even a slight global warming (anything over 1°C) is expected to harm agriculture in Africa. The latest IPCC report expects total world food production to decline for a rise above 3°C, and under present policies, that’s sadly likely to happen.
> 3. Wouldn’t we be better off (expend less wealth) on adaptation to a warmer climate?
We’ll have to do adaptation anyway. But no, that doesn’t mean it’s cheaper to just let things slide. The 2006 Stern review, for one, found the costs of action to limit emissions considerably lower than the costs of inaction.
http://webarchive.nationalarchives.gov.uk/+/http:/www.hm-treasury.gov.uk/independent_reviews/stern_review_economics_climate_change/sternreview_index.cfm
You may want to read Mark Lynas’s book, _Six Degrees_, and consider how you’d imagine adapting to some of the impacts described there for warming above 2°C. It’s not just about everything gradually getting a little hotter. It’s about crossing thresholds to dramatic, irreversible changes, like wiping out coral reefs.
My two cents: it’s a decision about what risks to take with the whole planet over the next centuries, so it calls more for moral wisdom and common-sense prudence than for financial smarts. Your question is a little bit like asking, “Instead of spending time and money on getting a healthy diet and plenty of exercise for myself and my family, wouldn’t I be better off saving up money for our coronary disease treatments?” – if you think about making that decision for your children and grandchildren as well.
>4.
Let’s pretend you didn’t even ask that, shall we?
Results … about 35,200 for +dagger +heart +theory +global+warming AGW
Enormous amount of copypaste for that one. I think RC has bots.
John P. Reisman (OSS Foundation) — You especially may wish to read Florin Diacu’s “Megadisasters: the science of predicting the next catastrophe”.
Looks like my earlier comment on “Garry” and his “What is the optimum temperature for life on Earth?” got wiped out for snarkiness. But this exact question, almost same phrase, was asked earlier (#556) by “Ken Rogers”, responded to by Gavin, and then by me (#564). And yet, here we are again. Is it question of the day on WUWT perhaps? Do these people ever read the replies to exactly the same question asked by others of their ilk?
Correction: I omitted a couple of important qualifications from my IPCC reference at ~969:
“These results, on the whole, project the *potential* for global food production to increase with increases in *local* average temperature over a range of 1 to 3ºC, but above this range to decrease.” (IPCC 2007, WG2, ch. 5, p. 275)
Ray L @ 902
could you please answer this for me. From my understanding, the growth in overall CO2 is both from fossil fuel burning and natural reaction to the raising temps. What percentage of this growth is from FF burning? From what I have been able to find out elsewhere, it seems the FF burning is less then half of the total of the “new” CO2.
Why i ask is because you stated that if we halved the present amount of CO2 in the atmosphere, we may see a decline of up to 3*C. But if the amount of CO2 being “put” into the atmosphere by FF burning is less then would accomplish that, then how can we get to that halving point?
Thanx for your time.
#963 TRY
To answer the question in your last paragraph about CO2 seasonal variability in the Northern Hemisphere, see:
http://scrippsco2.ucsd.edu/program_history/keeling_curve_lessons.html
I find this plot to have a certain majesty, showing the planet breathing during the course of a year. Unfortunately, it also shows the trend of carbon dioxide concentration is inexorably upward.
As you suspected, Southern Hemisphere plots show less carbon dioxide uptake during the growing season.
For other locations, see for example:
http://scrippsco2.ucsd.edu/graphics_gallery/mauna_loa_and_south_pole.html
These measurements are not easy to make accurately. In one recent presentation, the speaker said that at least 20% of their effort was spent on Quality Assurance, making sure that their data was accurate, checking against standards, etc.
There was supposed to be a satellite to measure CO2 concentrations (OCO), but there was a problem with the rocket, and it fell into the ocean.
Perhaps others can speak to whether there is a satellite continually monitoring IR spectra from Earth.
David Horton (971) — There are avid thread readers and there are those who don’t bother.
Well, Simon, I’m cured. I realize that you are now a troll. Your posts will now be ignored entirely by me. You are merely regurgitating what you have read in G&T, which has been shown to be not only wrong but ludicrous. Is it your contention that infrared radiation reflected from clouds cannot be absorbed by the ground, or is it your contention that infrared radiation absorbed by the ground will miraculously not warm it if it comes from clouds. Either way, sod off, clown!
Gavin, maybe a discussion on this NASA paper, purporting that CO2 is not well mixed in the trophosphere, “but rather lumpy” could be interesting.
http://www.jpl.nasa.gov/news/news.cfm?release=2009-196
> question of the day
Bots, I tell you. Put in a keyword like +warmist to filter and try it:
Results … about 3,490 for
optimum temperature for life on Earth climate +warmist
TRY, your first 3 points all have to do with absorption and emission of radiation. In such a discussion, it is helpful to think of an ideal absorber/radiator–a black body. Earth is not such a body–either over sea over land, but it’s a reasonable approximation to a gray body, when averaged over the surface–that is it absorbs/radiates a spectrum that is reasonably blackbody-shaped, but has some irregularities. We know in great detail what this spectrum looks like.
WRT CO2, it can only emit in the “lines” where it can absorb. There’s no addiational “blackbody” spectrum. Remember, however, that the “lines” get distorted by collisions, pressure, etc. We are talking about the energy levels of an oscillator. You can see, even semi-classically how distorting the atomic structure in a collision could change those slightly, right?
As to the planet, I guess you missed the beautiful figure Gavin had showing both heating of the troposphere and cooling of the stratosphere–right where you’d expect in, both in terms of wavelength and altitude. Here it is again–truly a gorgeous figure:
http://www.atmosphere.mpg.de/media/archive/1460.jpg
Here’s the thing, though. The sort of measurement you want to make is not a trivial one. Sure we can take a satellite picture or measurements, but it is just a snapshot. That’s not enough. We already know that short-term variability can dominate the signal due to CO2 on a timescale of a year of two, or even a few years. So, we need to know the solar energy coming in and being reflected out, and we need to be able to measure the IR radiation out. We need to be able to do this over a period of several years. What we are really talking about is a fleet of satellites if we want to answer this definitively, and that means we have to be able to process and calibrate data across instruments over the life of the mission. It’s not an easy measurement to get a 100% definitive answer beyond the 95-99% answers we already have.
Ladbury’s third law of reliability: ‘1’ may be the loneliest number, but ‘9’s and ‘0’s are the most expensive.
Rod B. @965, remember that you are trying to increase planetary albedo to sunlight, not stop warming due to backradiation. As such, the relevant spectral range is the visible.
Comment by Ron R. — 27 December 2009 @ 4:16 PM:
Thanks for that. You have found the perfect academic to discuss climate mechanisms with Simon Abingdon on an equal basis.
Steve
There may be a lead in the case of the stolen emails. Andy Revkin sent out a twitter query about this article http://www.dailymail.co.uk/news/worldnews/article-1238638/Chinese-hackers-linked-Warmergate-climate-change-leaked-emails-controversy.html which suggests Chinese intelligence may be responsible for the theft.
[Response: the daily mail is not a reliable source. -gavin]
Dhogaza says: “Well, climate science doesn’t support the notion of a ‘runaway greenhouse effect’ (ala venus or whatever), so perhaps it is better to focus on what climate science *is* telling us.”
Well, James Hansen would appear to disagree with you:
http://bigthink.com/jameshansen/the-science-of-global-catastrophe
And see here:
http://www.globalpolicy.org/component/content/article/212/45412.html
And here:
http://archive.greenpeace.org/climate/database/records/zgpz0638.html
Maybe you should point out to James Hansen that “climate science doesn’t support the notion of a ‘runaway greenhouse effect’.”
re: #963 ; para.5.
“I’ve seen people claim that a CO2 molecule will absorb the specific IR wavelengths, then radiate like a blackbody, and others clailm that the CO2 molecule will radiate the same wavelengths it absorbs”
The ‘others’ have it in this case. The black body claim you mention is wrong, because it disregards the emissivity coefficient which varies strongly with wavelength for CO2. The claim by the others rests on the law that the emissivity is equal to the absorptivity at thermal equilbrium.
If you want to consider black body behaviour for infra-red, consider solids and liquids rather than absorbing gases. These tend to absorb nearly all incoming infra-red irrespective of wavelength i.e they are ‘black’ for infra-red even though they may be coloured for visible light.
Ray wrote:
No, forcing is the energy the component adds to the system, and so for CO2, it increases logarithmically with concentration. The best guess is that if we double CO2 we add 3 degrees per doubling, so if we halved CO2 content (not the increase, the content), we’d drop 3 degrees on average.
The “START HERE” has several introductory treatments of the greenhouse effect. I recommend them.
Yes, that’s what I meant. The thing is, annual emissions are 1.5% of the content now, but the content is not rising by 1.5%, but by a lesser percent. This means the excess CO2 goes somewhere, to the oceans, into the plants, etc…
Thanks for correcting my calculation, yes, doubling by 2054.
Once emissions fall enough, let’s say to half the present amount (likely by 2045), and given that sinks will be increased, in spite of our emissions, CO2 content starts decreasing. Are we then facing cooling for the coming years (beyond 2050)? If so, we need to be careful not to overdo it.
By the way, coal plants also emit aerosols. Do they have a net warming or net cooling effect? I know you dislike aerosols, but we might just be in a situation where we have to choose between aerosols and warming.
We also need to be sure of the net effect of forests and other major factors, so we could fine tune them if need be.
We also need to consider that fossil fuels are a finite resource, so even if we don’t reduce emissions by law, they are sure to decrease through economic need because the fossil fuel energy source will become more and more expensive, while alternatives will become less and less expensive eventually overtaking fossil fuels, and from that point on, there’s no turning back.
Leo G., where is this “natural” CO2 supposed to be coming from? Right now, the oceans are still a sink for CO2, and we haven’t really triggered melting permafrosts or clathrates just yet. There is also contribution from land use, cement production, etc. It is true that the carbon cycle itself has huge fluxes of “natural” carbon, but the isotopic signature of the added CO2 shows it has a very large fossil (and therefore anthropogenic) component.
Is anybody aware of any paper/thesis etc where a simple heat calculation has been published. Several hundred years ago the only heat we produced was from fires here and there and a relatively few people. Now, we have more people and everything we do produces heat (even cars braking produce heat) Solar-electricity-eventually turns into hear. Wind , Nuclear, fossil it all does. Has anyone seen a publication where people simply looked a heat generation on our sphere 100 years ago and now even with a constant atmosphere. Does it matter if it is fossil fuels (GHG won;t help but is it the root cause)or was solar, nuclear etc. If I had a soccer ball with some metal in it so I could inductively heat it, the temperature of nearby air before I did would be lower than after. The same would be true if I burned it.
Has anyone seen such a simple analysis?
[Response: You can do it yourself. Look up total energy use and then convert it into an energy flux at the surface and then compare to the radiative forcing from CO2. It’s a good exercise in quantitative thinking. – gavin]
> cool roof paint
> the ideal
Remember, let not the ideal be the enemy of the good. We’re talking roof paints here.
>> relevant spectral range
Does a ‘cool roof’ have to be white in the human visible range? Let’s see what we can find:
http://scholar.google.com/scholar?q=cool+paint+visible+infrared+roof+car
http://www.therrci.org/UserFiles/file/Cool%20Construction%20Materials%20Offer%20Energy%20Savings,%20Reduce%20Smog.pdf
“Most high-albedo surfaces are light-colored, although selective surfaces which reflect a large portion of the infrared solar radiation, but which absorb some visible light, may be dark colored, yet have relatively high albedos.”
http://www.bentham.org/cheng/samples/cheng%201-1/Vinod%20C.%20Malshe.pdf
“Forty-five percent of the total solar energy is in the non-visible infrared region….
… Infrared reflective inorganic pigments are complex inorganic color pigments, which reflect the wavelengths in infrared region in addition to reflecting some visible light selectively….”
So, nope, you can, by the time you need to repaint your roof next time around, probably get any color or combination of colors you want, and likely can get metal-clad or shingle material that will be selective.
And some folks are working on materials that will change from absorbing to rejecting heat depending on whether you want to warm or cool the house.
I think a serious mistake in Simon Abingdon’s argument is the assumption that there is a night time and a day time. That sounds like a flat earth assumption. In reality, the planet is round and always about half of it is towards the sun, and about the other half is away from the sun. The half which is away from the sun gets warmed by the rotation of the planet. Energy is always added on the sun side, and always lost on the dark side. Without the atmosphere and the clouds on the dark side, the rotation of the planet wouldn’t be able to warm the dark side.
Therefore the atmosphere and the clouds are a necessary element for the rotation of the planet to warm the dark side.
Steve Fish #981, Actually the disintegration of communicative interaction gestures toward the culture of the public sphere.
Er, it speaks skeptic language too. I.E. If you can’t dazzle ’em with brilliance…
Note: not you Timothy, just funning you Bro. :-)
Leo G
I’m not Ray but … you’ve probably misunderstood something you’ve read (or, perhaps, have been lied to).
Generally the “natural reaction to the raising temps” refers to oceans outgassing CO2 as they warm. This happens if they’re in equilibrium with the atmosphere when warming begins, for instance as the earth begins to emerge from ice ages. The warming kicks the system out of equilibrium, leading to outgassing. They become a CO2 source.
However, if the oceans are in equilibrium with the atmosphere, and then you start pouring massive amounts of CO2 into the atmosphere – for instance, by burning massive amounts of fossil fuels – things are no longer in equilibrium, but this time it’s due to there being so much CO2 in the atmosphere. The oceans absorb CO2. Yes, they also warm, but if enough CO2 is continuously poured into the atmosphere, not fast enough for the oceans to saturate thus they continue to absorb CO2. They are a sink, not source, under this scenario.
(I’m simplifying, since there’s continuous exchange of gasses between the oceans and atmosphere so sink vs. source refers to the net balance if the exchange, and I’m ignoring the fact that the situation slowly changes as the oceans warm.)
The 50% figure you refer to *probably* something you’ve read backwards (or your source has read backwards).
It’s not that only 50% of the excess CO2 we’re seeing comes from fossil fuel burning.
It’s that CO2 concentrations in the atmosphere are only growing roughly 50% as fast as we pour CO2 into the atmosphere, with the oceans (mostly) absorbing the other 50%. That slows warming, but is having serious effects on ocean chemistry – the “ocean acidification” problem you may’ve heard about.
Hopefully this helps …
We had to endure mad max manacker with his claims about cyclicity, backed up by all the rigor of “Looks pretty cyclical to me.” Then we were assaulted by Matthew and his regurgitation of the “trend change in 1998” garbage. Then we had that stuff about “daggers to the heart” of AGW. And now Bruce Williams invents a fantasy about “SUSTAINED” increased in the GISS temperature record.
These crackpots have had their say. In fact they’ve had way more than their fair share of say. Enough is enough. Having to endure the same crap over and over again has made the comment threads worse than useless — they’re actually counterproductive.
I reiterate my suggestion: stand up for sanity by using the “delete” button often, or simply close threads to comments altogether. Yeah that would be bad, but still better than letting crackpots ruin the blog.
HI Gavin
Of course I could do it myself…but science moves buiding on each others work. There is no sense re-inventing any wheel. I am a Prof and could have grad students do this…but if it has already been done what is the point. I repeat..has anybody seen this. If so we can build on it, putting in various assumptions on the environment rather than re-do it. We want to add to existing knowledge, not re-invent it.
TH
[Response: It’s trivial. See here for a worked out example. – gavin]
> runaway greenhouse
It’s unlikely. It’s not unimaginable, as a few minutes spent with Google Scholar will show anyone who cares to do the reading.
http://scholar.google.com/scholar?q=runaway+greenhouse+terrestrial
Don’t argue with conclusory statements; citations are much less likely to run off into endless exchanges of beliefs.
Tamino, You obviously know exponentially more about climate change than I do, but you are too damned sensitive to noise. Have you ever been a teacher? You don’t always get “nice” questions. I, for one, can learn a lot by hearing people respond to what you, undoubtedly, think are crackpot or even malicious ideas.
Maybe the believer-scientific choir all singing together would produce beautiful music…but would anyone be listening? If you guys can cut through the noise of weather and keep your eye on climate, you (undoubtedly precise, focused, and orderly scientific types), at least hypothetically, should also be able to deal better with human noise. Good grief, it is what humans do.
Now to reveal more of my own ignorance, in those links to your site where you showed the ten year temperatures in order to demonstrate that there had NOT been cooling, what does the anomalie column represent or mean?
“I reiterate my suggestion: stand up for sanity by using the “delete” button often, or simply close threads to comments altogether. Yeah that would be bad, but still better than letting crackpots ruin the blog.”
Apparently the reality of the CRU expose’ has not sunk in.
dhogaza, thanx for that.
So let’s say, (very simply) in a perfect world, over the next 20-30 years, we basically stop all burning of FF for energy, and the CO2 content in the atmosphere is now above 400 PPM, how do we get to halving that amount? Will the CO2 sinks keep on absorbing? or are they now at equilibrium to their new state?
Or is there a natural tendency for the atmosphere to re-align itself to the 250-300 PPM?
I guess what I am trying to understand, is if we even get to a point where the net increase of CO2 in the atmosphere is finally stopped, is mankind going to be able to lower it back to a safer level? or do we have to adapt to a new reality?
Thanx for your time.
Re: the opportunity to suggest future posts
Given the interesting discussion between Blair Dowden and Timothy Chase about snowball earth and the possibility of a runaway greenhouse and that fact both these “educated lay” commenter’s are probably stretching the limits of their own knowledge, perhaps these would be good topics for some future posts?
Having a look at Hansen’s 2008 Bjerknes lecture, it is clear that the possibility of a runaway greenhouse is his personal opinion, given the increase in solar irradiance since the last time C02 was extremely high and the “unprecedented speed of positive forcing”.
Searching back through RC I couldn’t find any posts on this area, apart from an inline comment from Raypierre back in 05 where he stated a runaway greenhouse was extremely unlikely.
A post expanding on and, (if possible) explaining the reasons for the contrasting views of Hansen and others such as Ray on this area would be really interesting.
Re Ron R. 966
Oh dear!
My first reaction was to try and rapidly decipher what you were writing. Failing that and realizing that I would have to read it rather closely but not being in quite the right mood for that sort of thing (I just got back from taking photos for some panoramas — but where I was fighting the sun rather than having it work for me), I decided to try and classify it. The best I could come up with was existentialism or deconstructionism. Unfortunately it was reminding me more of deconstructionism than existentialism — and of strong deconstructionism at that.
Really not my cup of tea.
Then I realized that your questions suggested that you didn’t have any better a handle on what you had posted than I did, and at that point I thought plagiarism. Oddly enough, it was at that point that I started to feel more warmly towards you. But I wanted to know where you were getting you text, so I started putting fragments into Google but without quotes. Paul de Mann. Herbert Marcuse. But only words and phrases were coming up. No complete sentences. “Typing something out of a book?,” I wondered.
And then I saw the link.
Leo G:
search:
http://scholar.google.com/scholar?q=biogeochemical+cycling+carbon+dioxide
It’s slow.