With some hubub recently over the 350.org day (designed to highlight the opinion that we must return the Earth to a 350 parts per million atmospheric CO2 level) I thought it might be a good idea to have a look at what the reversal might gain us.
For this, I’m drawing on the excellent guest post made by Bill Illis here on 11/25/2008 titled:
Adjusting Temperatures for the ENSO and the AMO
One of the graphs (along with a model in a zip file) that Bill presented in that guest post was this graph, which I’ve annotated to show the 350 PPM desired by activists, versus the 388 PPM (MLO seasonally corrected value) where we are now:
Here is the same graph, annotated again with intersecting lines and values, and zoomed on the areas of interest.
Depending on whether you believe the models or the actual observations determines what value would be gained from a reduction to 350 PPM.
For belief in the models we’d get approximately 0.5°C drop in temperature.
For belief in the observations (RSS HadCRUT3 data) we’d get approximately 0.3°C drop in temperature.
Split the difference if you don’t like either and call it 0.4°C.
The key point here is that to get to 350PPM, it would be extremely difficult if not impossible to accomplish. Alternate energy just hasn’t risen to the challenge yet, and the world populace that depends on electricity isn’t likely to tolerate shutting down their energy use to get there.
China and India have said they won’t go along with suggested reductions, and are coming up with their own ideas prior to Copenhagen. Thus is the quandary faced by 350.org supporters.
As a side note, the 350PPM target was Dr. Jim Hansen’s idea:
Target Atmospheric CO2: Where Should Humanity Aim?
Since Hansen can’t even predict the effect of climate change 20 years out in his own neighborhood, one wonders why some people take the 350 PPM target suggestion seriously.
Dan (16:37:20),
You asked where that chart came from: click
The problem with this analysis is that radiation absorbed by CO2 is not largely transmitted upwards by multiple reradiation and absorbtion in band after band. Go outside when the eagles are flying (you won’t be able to do that much longer when wind farms are erected and kill them all, so go now). You’ll see them spread their wings and catch the ‘thermal’, rising ever higher as the hot air column punches its way through the denser, cooler air above, carrying the eagle (and the heat) to vast heights by convection, not by radiation.
Now the thing is, the eagles circle in maybe a few hundred yards (hard to tell, distance makes judgement faulty), but definitely not anything like three kilometres, which is, I believe, the kind of cell spacing in climate models. So they completely miss the physics of the primary cooling mode involving CO2-affected wavelengths.
Bill Illis “I imagine the 350 ppm is just a stretch target which is based on another target set by the EU and Hansen of 450 ppm. This level is contained in Hansen’s latest paper in which he says that all the ice will melt if we get over 450 ppm but that is not supported at all by the data contained in the paper.”
Hansen should be tried for malfeasance.
Chris
Norfolk, VA, USA
More co2 is more life.
Is it safe to say that some who want to reduce co2 also want to reduce the population?
Are they some of the same that want DDT kept out of Africa?
Kum Dollison (17:42:54) :
2007 – Hot Year – CO2 increase was 2.53 ppm
2007 was a hot year? You may want to check the data again. Temperatures took a nose dive in 2007.
Wow. This post fails in so many ways:
1) By trying to fit CO2 concentration directly to temperature, it ignores the fact that the oceans have significant inertia, and that the earth system does not instantly equilibrate. eg, “warming in the pipeline”.
2) Surprisingly, given what this website usually talks about, it totally ignores any contributions of anything other substance or system: solar changes, ENSO variability, aerosol emissions, other greenhouse gases
3) Finally, the logarithmic relationship of CO2 and forcing is only true over a limited range of concentrations, so extrapolating back to zero ppm is ridiculous. Also temperature increases as the fourth root of radiative forcing.
Deepest Darkest Iowa (13:00:18) :
The notion that c02 increase or decrease would lead to a temperature change is deceptive. There are so many variables that overwhelm c02 that it makes no sense to compare even 200ppm to 600ppm, regardless of 390 to 350ppm since they both do exactly the same thing. Its like comparing a human who has 100,000 hairs on his head is going to conserve more heat than one who has 99,000 hairs.
In isolated experiments, this logarithmic factor may be quite significant (although Angstrom didn’t think so when he made direct measurements of c02 doubling – radiation going through it hardly changed). On the earth however, its irrelevant whether a theoretical 100ppm extra will increase the temperature by 0.002C, particularly at the most effective point of c02 absorption requires earth’s most subzero temperatures. Since c02 absorbs all heat available to it in 12 metres, it is not possible to create extra heat even logarithmically with further additions – all that happen is the distance shortening of c02 by 6 metres, assuming a doubling. It doesn’t change the temperature. Where c02 is said to be most effective, in the upper tropopause, its peaks have already depleted and it interferes with heat at its shoulers, which is 5% as efficient as at its peaks – and this is where it competes with the bandwidths of nitrogen and oxygen to *trap* heat. there are millions more of these molecules than c02 molecules in that region.
If some in government in the USA get their way the reduction in co2 will force the co2 output in the USA to equal that of Haiti :
Marcus (19:41:02) :
Marcus,
You may want to rethink what you said in your comment. Please reread the post.
I don’t see anywhere in the post that it is the summation of what WattsUpWithThat is all about. Did you see that?
As others here and elsewhere have observed (Ian Clark, Tim Ball, Larry Lindzen in Great Global Warming Swindle, for example), the paleo record suggests CO2 is following or lagging temperature.
With respect, aren’t you giving warmers a bit more of a boost than they need to make their case?
George E. Smith (17:41:09)
the delays inferred from c02 absorbing and emitting radiation might be useful if a time limit were put on them, which is a less than a billionth of a second for the transformation to take place. it is saturated in this period of time, in order for it to re-emit to other molecules in the atmosphere – mainly nitrogen and c02, although only the 1st point of absorbtion – at ground level to 12 metres is the only important part for the greenhouse effect – during the process of re-emission, it goes in all directions meaning no change of heat from re-emission.
This all falls by the wayside, given convectional currents operating at this level
oops. typos:
should read “mainly “nitrogen and oxygen” at line 5
“”” _Jim (18:44:09) :
George E. Smith (18:08:51) :
Excerpt: Yes it is true that there is a cascade of absorptions and re-emissions; not from the CO2 molecule, but from the ordinary atmospheric gases, which are heated by collisions with the excited CO2 molecules.
No mention of the atmospheric window at 10 um (which happens to coincide with a moving (~T^4) spectral peak for temperatures of around 288 K … does it not?) which allows energy transmittal directly into space from the surface?
How much (energy %-wise of the total IR from the surface) excapes directly into space via the 10 um LWIR window for any given surface temp (like 288K)? “””
Well Jim; I could fill several Physics tex books with the things that were NOT mentioned in my post.
I believe I mentioned that at 288K; the purported mean global surface temperature (the origin of most of the LWIR); the spectral peak of the LWIR emissions is about 10.1 microns. Now Black Body radiuation Physics tells us that very closely 25% of the energy of a BB radiator is emitted below the peak wavelength; and as you say, that is within the 10 micron “atmospheric window”. It’s a bit more accurate to describe that as the water vapor atmospheric window because it is bounded on both sides by H2O absorption bands. So yes there is about 25% of the surface emissions that aren’t going to be attenuated much on their way to outer space. And putting the CO2 band at about 13.5 to 16.5 microns; that puts it out on the falling tail of the emission peak. And for the tropical deserts, where surface temperatures might be +60 deg C or higher, the LWIR spectral peak is more like 8.8 microns, so it is even further removed from the CO2 15 micron band.
And incidently the peak of the emission spectrum goes as 1/T; not as T^4 which you stated.
Ron House goes on to state that the picture I painted is wrong, and the heat is carried aloft by convection. while ron is correct that a lot of heat is carried aloft by convection; that is a slow process compared to radiation. The surface radiation can escape (if it escapes) in less than a millisecond, which is how long it takes for a photon to travel 300 km. Even the most agressive convection can’t top that cooling speed; but I’m in agreement with Ron, than convection is a powerful cooling process; and in the case of the atmosphere is much more effective than conduction.
But ultimately, it is radiation that must carry the energy out into space; convection doesn’t operaqte in the vaccuum of space; well not efficiently anyway; but even then more effective than conduction in outer space.
I’m sure other will mention still other things I did not mention; as I said; that would fill many Physics texts.
Why not address that which I DID mention.
My whole point is that much of the surface emitted LWIR can exit to space in a millisecond having been stopped by nothing at all. It does not all have to pass through the hands of some CO2 traffic police; which is the inevitable conclusion of the popular notion that the radiation to space is from stratospheric cold low density CO2; and it is that radiation flux which must balance the sun’s insolation. the surface temperature must the be hotter than that high altitude space radiator. That is only the result for energy that IS transported to the upper reaches of the atmosphere by convection and radiation, and deposited there, such as by the condensation and freezing of water vapor.
In fact radiated LWIR is emitted at all levels of the atmosphere in a manner consistent with the local temperature , which is why the observed earth LWIR spectrum, is NOT a black body spectrum, because it is not an isothermal emitter.
How did Hanson arrive at a target of 350 ppm CO2? Did he work his way through complex computations of all the possible permutations and outcomes? Can we see the data and formulas to see his thought process?
Nah, he just made a wildass guess.
You are truly playing to the ignorant on this one, assuming ocean temperatures are delayed in heating then those graphs aren’t worthy of even posting.
What you haven’t shown is 350ppm (over time) will eventually be hotter than what it is today! Look, I’ve seen better than this from you guy’s, you can do better.
I wanted to draw your attention to the fact that the above reasoning is clearly not adapted to the greenhouse situation. The majority of the reabsorption of IRs takes place at the boundary between the upper troposphere and the lower stratosphere, where the concentrations in CO2 is much less and hence quite far from saturation. So there’s still plenty of room for an increased greenhouse effect.
Windguy,
“What you haven’t shown is 350ppm (over time) will eventually be hotter than what it is today! Look, I’ve seen better than this from you guy’s, you can do better.”
Criticism is easy. Why don’t you show these things you are asking others to do?
As usual, lots of clever & interesting stuff here. But, thanks to this silly (& unachievable) “350” CO2 target, we are all getting hung up on CO2! There is plenty of evidence (despite Icarus) that more CO2 is good for plant yields but otherwise has little effect on anything (pretty much as you would expect from a harmless trace gas).
Of course, this whole hoax started because of the alleged link between CO2 & temperature and the apocalyptic “scenarios” of eco-fascists and supposed scientists who tirelessly build their scary models with cherry picked and distorted data whilst refusing to allow the light of independent scrutiny to shine on the raw data and algorithms.
Icarus and the rest of them think in accordance with this ‘orthodoxy’ and believe that warming would be a Very Bad Thing Indeed.
Myself, I think a bit of warming would probably be more a good thing than a bad thing. But in the spirit of compromise, I have a suggestion.
Instead of worrying about trying to reduce CO2 levels to 350ppmv, why not reduce global temperatures to what they were ten years ago! That might be even tougher of course! Reduce temperatures…..Oh, wait a minute,….errr…ummm?
Dang it! Nature beat me to it!
My understanding from the scientific literature is that the current CO2 levels are responsible for about 15% increase in growth yields.
If I was a scientists designing such an experiment, I would set up two greenhouses, one containing 280ppm of CO2 and the other 380ppm, then plant the same crops with the same soil and nutrients and temperature and humidity and water and measure their yields.
Surely this is how they get these figures. Why is it necessary to try and compare yields today with those 30 years ago to obtain the contribution of CO2, as one poster has claimed? It all sounds like a smoke screen argument to me.
“What does a reduction to 350 PPM of CO2 get you?”
A worldwide catastrophic economic depression, a least in those countries buying in to such fantasy. China and India will barely notice, as they have so much development yet to go; the world will blast past 400 ppm and they’ll keep on building their power infrastructure to satisfy their own populace’s wants.
Like some others, I believe that cutting CO2 to 350 would probably have no measurable effect. And if it did, it would be bad news.
It seems to me that nature has been conducting an excellent experiment over the last few hundred million years. For various reasons the climate has been changing all the time, sometimes slowly, sometimes very dramatically (e.g. the ice ages). Fortunately the ice cores let us observe this experiment quite accurately for the last half million years. If CO2 can drive the climate, then this should provide an unmistakable signal in the ice cores.
The ice cores show a dramatic correlation between temperature and CO2. At first, this must have been a powerful boost for AGW. It would have seemed obvious that the ice cores proved beyond doubt that CO2 was driving the climate.
But now we know differently. Higher resolution measurements in recent years clearly show that the CO2 graph lags behind the temperature graph by roughly a thousand years. There seems little doubt that CO2 was being driven by temperature through the action of the oceans. When Gore says “When the carbon dioxide goes up, the temperature goes up” he should have said “When the temperature goes up, the carbon dioxide goes up”.
As far as I’m aware, the ice core data shows no trace of CO2 affecting temperatures. Surely, if the CO2 forcing used by the IPCC is right, then there should be clear evidence of this in the ice cores. But if there is no such evidence, then the only reasonable conclusion is that the IPCC is spectacularly wrong and that CO2 has a negligible effect on the climate.
It looks like a win, win situation as far as CO2 is concerned. Increased CO2 has almost certainly increased world food production while having no significant effect on the climate. To demonise CO2 as a pollutant is completely mad and anti-scientific. CO2 is not a greenhouse gas (greenhouses work by trapping warm air and not by trapping infra red radiation). CO2 is a *green* gas.
Many claim that the CO2 increase has made the world more stormy, with more droughts, hurricanes and floods. But, unlike the newspaper headlines, the scientific data tells a different story. And history also tells a different story. Compared to a few centuries ago, when the world was enduring the Little Ice Age, weather and climate conditions in the modern world are far, far more benign. During the Little Ice Age some storms and floods killed hundreds of thousands.
In my humble opinion, anyone who wants to return to a colder world is completely barking mad.
Chris
>>
Illinois corn ran around 130 bu/acre when CO2 was 350 ppm. At the current CO2 level, it runs about 180 bu/acre.
<<
We can increase the supply of Illinois corn by a large fraction by simply putting an end to the idiocy that we are better off when we burn corn in the form of ethanol in our automobiles. We should save hydrocarbons that are not edible for conversion into motor vehcile fuels and save the edible ones for conversion into food.
Nemetz, I guess it’s all relative, but 2007 started out hot, and cooled as it went along. Looking at UAH it averaged 0.29. Compared, for instance to 2008 which came in at 0.05.
http://vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt
Icarus,
I would suggest REAL data instead of green propaganda …
“Elevated CO2 has been predicted to have little or no effect on plants with the C4 pathway of photosynthesis, such as corn. In 2002 we ran the first experiment to test the effect of elevated CO2 on a C4 crop in a area of major production. Surprisingly, elevated CO2 stimulated grain yield by 26 %.”
http://soyface.illinois.edu/results/AAAS%202004%20poster%20Leakey.pdf
Icarus (13:48:15) :
“Ready, Fire, Aim” is not a scientific approach to resolving issues. That, I believe, has been clearly demonstrated numerous times.