[paul.fr]

Is it possible that Henry is just mistaken, and that he is thinking of Co2 causing Stratospheric cooling?

[Henry Pool (OP)]

Yes, my idea was that if CO2 acts as a blanket, it might also act as a shield. But let me rather stay out of this discussion, because what O says is true. I am not qualified in this field and don't have the same access to information like you people do.

[Ophiolite]

Yes, my idea was that if CO2 acts as a blanket, it might also act as a shield.

And that is a perfectly reasonable hypothesis. If we did not have the body of observation and experiment that we do, then it could be a valid hypothesis. However, the point that invalidates it is that the incoming radiation is different in wavelength/frequency from the outgoing radiation. CO2 is largely transparent to the incoming wavelengths, but opaque to outgoing wavelengths. That is the central point I have tried to communicate in my posts and it has been made by several others.

Rgds,
ET

[paul.fr]

Yes, my idea was that if CO2 acts as a blanket, it might also act as a shield. But let me rather stay out of this discussion, because what O says is true. I am not qualified in this field and don't have the same access to information like you people do.

Henry, you are more than welcome to participate in your own topic, I think you just have to be more willing to explore what others are saying and the information they give. And, perhaps, try and make you point clearer.

It took me a while to figure out what you were getting at, but hey, we all struggle at times to get people to understand what and where we are coming from. Anyway, here are a few links about the cooling effect of Co2 in the upper atmosphere:

Global Warming causes Stratospheric cooling
Stratospheric cooling

Cooling of the stratosphere isn't just the result of ozone destruction but is also caused by the release of carbon dioxide in the troposphere.  Therefore, global warming in the troposphere and stratospheric cooling due to ozone loss are parallel effects.  As cooling increases, development of the ozone layer can be affected because a cold stratosphere is necessary for ozone depletion.

So releasing more carbon dioxide may not only increase global warming but may also contribute to the formation of the ozone hole.  The system is pretty complicated and so we try to give just an overview of it here.

Is the stratosphere cooling?
It's, of course, harder to measure the temperature in the stratosphere than in the troposphere where we have a network of measurement stations.  Stratospheric temperature measurements do exist.  They have been made using weather balloons, microwave sounding units, rocketsondes, LIDAR and satellites.  Most of these readings only go back two or three decades at most and there are large uncertainities associated with the data.

The lower stratosphere appears to be cooling by about 0.5°C per decade.  This cooling trend is interrupted by large volcanic eruptions which lead to a temporary warming of the stratosphere and last for one to two years.   Calculations from many research institutes generally estimate the cooling trend for the last two decades (1979-2000) to be greater than for the previous period (1958-1978).

Why does the stratosphere cool?
There are several reasons why the stratosphere is cooling. The two best understood are:

1) depletion of stratospheric ozone
2) increase in atmospheric carbon dioxide.

Cooling due to ozone depletion

The first effect is easy to understand. Less ozone leads to less absorption of ultra-violet radiation from the Sun. As a result, solar radiation is not converted into heat radiation in the stratosphere.  So cooling due to ozone depletion is simply reduced heating as a consequence of reduced absorption of ultra-violet radiation.  Ozone also acts as a greenhouse gas in the lower stratosphere.  Less ozone means less absorption of infra-red heat radiation and therefore less heat trapping.

At an altitude of about 20 km, the effects of ultra-violet and infra-red radiation are about the same.  Ozone levels decrease the higher we go in the atmosphere but there are other greenhouse gases present in the air which we have to consider.

 
 

Cooling due to the greenhouse effect

The second effect is more complicated. Greenhouse gases (CO2, O3, CFC) absorb infra-red radiation from the surface of the Earth and trap the heat in the troposphere.  If this absorption is really strong, the greenhouse gas blocks most of the outgoing infra-red radiation close to the Earth's surface.  This means that only a small amount of outgoing infra-red radiation reaches carbon dioxide in the upper troposphere and the lower stratosphere.  On the other hand, carbon dioxide emits heat radiation, which is lost from the stratosphere into space.  In the stratosphere, this emission of heat becomes larger than the energy  received from below by absorption and, as a result, there is a net energy loss from the stratosphere and a resulting cooling.  Other greenhouse gases, such as ozone and chlorofluorocarbons (CFC's), have a weaker impact because their concentrations in the troposphere are smaller. They do not entirely block the whole radiation in their wavelength regime so some reaches the stratosphere where it can be absorbed and, as a consequence, heat this region of the atmosphere.

 
Where does cooling take place?
The impact of decreasing ozone concentrations is largest in the lower stratosphere, at an altitude of around 20 km, whereas increases in carbon dioxide lead to highest cooling at altitudes between 40 and 50 km (Figure 3).  All these different effects mean that some parts of the stratosphere are cooling more than others.

Other influences
It is possible that greenhouse warming could disturb the heating of the Arctic stratosphere by changing planetary waves.  These waves are triggered by the surface structure in the Northern Hemisphere (mountain ranges like the Himalayas, or the alternation of land and sea).  Recent studies show that increases in the stratospheric water vapour concentration could also have a strong cooling effect, comparable to the effect of ozone loss.

Conclusions
We now know that stratospheric cooling and tropospheric warming are intimately connected and that carbon dioxide plays a part in both processes.  At present, however, our understanding of stratospheric cooling is not complete and further research has to be done.  We do, however, already know that observed and predicted cooling in the stratosphere makes the formation of an Arctic ozone hole more likely. 

The second link from Espere is rather good, in fact, somewhere on their site you can dowload a climatology PDF. It's a large file and goes in to all aspects of climate and meteorology, I can look around for the link if you want?

[Henry Pool (OP)]

Thanks Paul, but yes, I already was worried that it would me more complicated up there then I thought it would be. It goes a little bit above my head. Anyway, I said I just wanted to observe and learn, rather then participate. Let me phrase a new question, post this, and then let me just observe what you people can come up with. 

[112inky]

the warming effect CO2> cooling effect caused by CO2). 

[Bored chemist]

the warming effect CO2> cooling effect caused by CO2). 

Principally because the heating effect exists, but the cooling effect doesn't.

[shockwavemikey65]

You're welcome.


And in response to your question, noone blames CO2 for ALL the GCC (please stop calling it GW - it isn't). CO2 is PART of it, and is perhaps the most easily addressed. It is well established that CO2 is a GHG, yes? Increased GHGs increases retained energy, yes? CO2 has increased by 25% in the last few decades, yes?

I'm not sure I see what the problem is. Yes, there are other influences on GCC, but (to use that awful phrase) CO2 provides the low-hanging fruit, and it is predicted through extensive modelling, that GCC in response to CO2 increases, is not linear due to feedback processes. By the time that it has reached 750 ppm, there is a roughly 50% likelihood of an increase in temperature of 6 or 7°C, which will have profound effects on the net carbon storage of forests, for example. They will no longer be sinks, but sources due to reductions in photosynthesis, reduced productivity and increased mortality. And if the forests go, not to put too fine a point on it, you're buggered. Completely. Because of CO2.

Well if this is such a problem is there any method to break up the atoms of CO2 IE(an alternative propellant used to propel a canister into the atmosphere where it will release a non hazardous agent which will disassociate the molecules of CO2 into two oxygen atoms and a carbon atom? JW!

[sgweightloss]

we blame the carbon emissions which results in the green house gas for global warmimg, without offering any physical evidence or proof. hence i dont really know that carbon dioxide is causing global warming!

[BenV]

we blame the carbon emissions which results in the green house gas for global warmimg, without offering any physical evidence or proof. hence i dont really know that carbon dioxide is causing global warming!

In that case, I don't think you've read any of this thread!

[Henry Pool (OP)]

My investigations have turned me into a total skeptic. I very much doubt whether carbon dioxide is to blame for global warming. It is not that I deny that global warming is happening. Read my final report on the other thread: How much is the increase in carbon dioxide every year?

[carbon_action]

If we keep an open mind and try to look at the evidence that there is - we must (I think) feel in our gut that global temperature increases in the geological record correspond eerily closely with increases in atmospheric CO2 and CH4. 

Of course some global climate change is due to natural cycles such as Earth's orbit around the Sun.  Sunspot activity and the angle of tilt of Earth relative to the Sun.  But if you look at all these cycles and atmospheric gas concentrations it does look at this stage as if we have pumped out too much gas into the atmosphere and it is now about to lead to civilisation changing impacts.  Even the Dutch East India Company wrote about climate damage from emissions way back in 1840/1850s so its not a new concern. 

[litespeed]

CO2,

This trace gas has been as high as 3000 parts per million during the Jurasic era to level that now is less the 300 parts per million.  Carbon dioxide increases have not been associated with the end of the last ice age, or with the midieval warming period.

Further, recent increases in CO2 seem entirely independent of the warming after the 'little ice' age that ended in the 1850's, and the current cooling trend. IMHO, simple minded individuals with superiority complexes just make this crap up out of thin air.

First, what sane person wants a colder planet anyway. Jeezzuz Friggn Christ. Crop failure, pestulence and plaque, vast population migrations, pilage plunder and mass carnage and exterminaion. [The victors seem routinely to genetically remove the male populations and happily breed with the surviving femails.]

And in the last twenty years I can not recall any of these Carbonistas even consider solar output.  As of now, the sunspot cycle is about two years late.  It seems stuck in a solar minimum, which means 1% less solar output.  And this has happened before. GOOGLE The Maunder Minimum. http://science.jrank.org/pages/4184/Maunder-Minimum.html

The Carbonistas are dangerous cultists, and need to be watched very closely.  Of course they will seldom be found anywhere near a cold climate.

[litespeed]

Climate Change, constant change:

Causes are beyond comprehension. They include precesion of the equinoxes, the orbital changes of the earth itself. The earths relative position in the various galactic spirals. Solar output varies.  And believe it or not, the amount of cosmic rays can significanly affect cloud formation and thermal transfer.

Then there is continental drift and disruption of thermic oceanic conveyor belts. Add in one or two Super Volcanos, or an astroid impact or two, and we as a species seem an oddity. In fact, some geneticists claim the human race, in the last ice age era, was reduced to fewer then a couple of thousand individual.

Chuckle: apparently there is more genetic diversity among a single troup of Chimps then between the entire human population. In other words, in Las Vegas terms. We are a Royal Flush.

And now we have chumps [not chimps] telling us the planet is getting too warm. Fat Ruck. How many of these thermocline extreem bacterial throw backs do you see setting up survival camps in Northern Alaska to avoid the inevitable catastrophy of Global Warming.

Believe me, superstition is alive and well in all the usual suspect places. The entertainement industry, the Official Doctrine Of Academic Purity. And of course all the suplicant and suckup undergraduates of any instutuion that provides some sort of poster as its accademic degree.

[litespeed]

Henry:

CO2 has varied from 3000 parts per million during Dinosaur era to the lower levels we now observe.  CO2 is a very minor trace gas in the atmosphere that, climatically speaking, approaches insignificance. For instance, the midieval era (renaisance) experienced a warming spell well in excess of anything we see today. Then it got cool for a century or more in the 1600s and beyond.  The only observable connection was a reduction in Sun Spots in the 1600's, and a warming trend from the mid 1800's to the late 20th century that is simply one of thousand unexplained shifts over the billions of world history years..

So, even though CO2 concentrations are higher now then 150 years ago, and about a hundred times less then the dynosaur era, the climate is once again cooling. The sunspot cycle is at least two years late. If we have a solar minimum sunspots for nearly a century, as was the case in the 1600's, I recommend buying Polar Bear Pelt Futures.

[Bored chemist]

My investigations have turned me into a total skeptic. I very much doubt whether carbon dioxide is to blame for global warming. It is not that I deny that global warming is happening. Read my final report on the other thread: How much is the increase in carbon dioxide every year?

Well, we have tried to explain it to you. If you refuse to listen that's your problem.
Incidentally the reason that most people concerned with climate change ignore the sunspot cyly is that it's rather too short- term to have a significant effect.
It's like saying that CO2 can't matter because it only affects temperature by a few degrees whereas going from noon to midnight will generally reduce the temperature by 10 degrees.
The point is that the sun comes up in the morning, the sunspots come and go but, on a human timescale, we are stuck with the CO2
Frankly, anyone who didn't realise that hasn't thought the question through.

[Madidus_Scientia]

My investigations have turned me into a total skeptic. I very much doubt whether carbon dioxide is to blame for global warming. It is not that I deny that global warming is happening. Read my final report on the other thread: How much is the increase in carbon dioxide every year?

No, skeptical thinking requires rational thinking supported by facts. You're a cynic, not a skeptic.

[litespeed]

dentstudent - You wrote: "...CO2 has increased by 25% in the last few decades, yes? ...
By the time that it has reached 750 ppm, there is a roughly 50% likelihood of an increase in temperature of 6 or 7°C"

First, the climate has been cooling for about a decade and with the sunspot cycle gone missing I am looking for bargains in sweater sales.  Further, I have seen estimates the Roman era was warmer then now (The Romans cultivated grapes in Britain and exported wine.)  And finally, the midieval warming was substantially greater then now.

FROM WIKIPEDIA:
"A radiocarbon-dated box core in the Sargasso Sea shows that the sea surface temperature was approximately 1 °C (1.8 °F) cooler than today approximately 400 years ago (the Little Ice Age) and 1700 years ago, and approximately 1 °C warmer than today 1000 years ago (the Medieval Warm Period).[

http://en.wikipedia.org/wiki/Medieval_Warm_Period



,

 By the time that it has reached 750 ppm, there is a roughly 50% likelihood of an increase in temperature of 6 or 7°C, which will have profound effects on the net carbon storage of forests, for example. They will no longer be sinks, but sources due to reductions in photosynthesis, reduced productivity and increased mortality. And if the forests go, not to put too fine a point on it, you're buggered. Completely. Because of CO2.

   

[litespeed]

Hey Bored

Get a grip on your chicken-little roost already. Geeze. Warm is good, cold is bad, and right now it looks possible we might need baby harp seal sweaters shortly. The weather is like the stock market. It varies. Right now it is getting cooler.

But in general it just varies. It varies big (ice ages), it varies small, (el Ninno and the Pacific occilation). And sometimes it just varies. In historical times we have significant warming and cooling above and below current temperatures without any C02 changes at all.

I think all this hysteria is simply caused by the end of the most recent little ice age that ended in the mid 1800, coincident to the industrial revolution. If you are comming out of an ice age you might suspect the temperature is getting warmer because you are getting out of an ice age. 

The worst possible thing that can happen now is another Little Ice Age. That is because agriculturally productive land will decrease significantly in the higher lattitudes. Think Canada and Asia. What sort of fool wishes to cool the planet out of what is historical one of the best climate optimums we have seen, in all of recorded history.

Just ask the people 1,000 years ago who went from a climate warmer then now to one that became cooler then now. Jeeze, the entire Viking colonialization of Greenland starved to death, and I seem to remember famines and plagues that subsequently killed off maybe half the population of Europe. I suppose it could devastate the several hundred pupfish in death valley, but who knows.

http://en.wikipedia.org/wiki/Medieval_Warm_Period

 

[yor_on]

Bored chemist is one of the more knowledgeable guys on this site. If you had made the effort to check on his posts you would have realized that.

As for the rest of the BS spread here take a look at this post of mine.
Read the reports, I assume you know how to read?

At least you seem to know how to spread dung.
http://www.thenakedscientists.com/forum/index.php?topic=24403.msg281967#msg281967