quote:

Originally posted by suricat:
The problem with your IPCC links is that the IPCC only speculate on the things that they are mandated to speculate upon. The IPCC make no continuing mention of a stratospheric radiative forcing - or ozone destroying - compound/element unless it was 'ordained' to be significant in its nature for inclusion by the IPCC, or by way of the 'Montreal Accord' (at least that is apparently the way it has ended up).

Yes and as was the case with regards to the original topic the IPCC it seems are not only selecting the science that sells AGW but are also manipulating raw data and presenting it as science. This behaviour should be condemned by all intelligent people because it amounts to nothing more than lying through science. This is not science, it is politics and such politics proclaimed there were WMD in Iraq when there wasn't. These same tactics are being used to proclaim we cause global warming - you just have to be sceptical, or a fool to fall for the same trick twice.

Suricat,

quote:

The fact that an element (O3) has been greatly anthropologically reduced in the atmosphere (particularly the stratosphere) doesn't seem to be considered as significantly anthropological in the IPCC's mandate as I believe it should (apparently only the reduction of it is anthropologic, so now it has depleted at the poles its action is mostly ignored and 'other' radiative forcings are the main anthropologic 'focus'), they then continue only to consider that 'harmful' anthropological O3 in the troposphere is a difficult element to predict due to measurement problems and has an observed increase in its abundance (this mostly excludes the reason for the anthropologic 'cooling' of the stratosphere and the subsequent inclusion of tropospheric molecular oxygen (just as potent a 'radiative forcing gas' as O3) in radiative absorption of the ultraviolet spectrum (and above?) other than the fact that the stratosphere is no longer 'forcing' the troposphere) which is expected to be difficult to model.

I don't mean to be rude, but the above paragraph is only one sentence, so I had trouble with the sense of it all.

What makes you think they don't correctly consider ozone? I've only scan read the section on ozone. They note that the reduction in ozone has caused a negative radiative forcing (-0.15W per metre squared - about a tenth of the positive CO2 forcing), and that some of the change is anthropogenic and some maybe not.

I didn't think that O2 was radiatively active. Besides, ozone is measured in parts per billion, so a reduction in ozone implies a tiny tiny change to the composition of the main atmospheric molecules.

Steve_M

Sorry for the bad grammar in that posting, but the post was an old response to another thread that, I think, moved on before I posted it. However, the post was made in response to a request by True Sceptic for an 'authoritative' replacement for Wiki. The trouble is, there isn't one! The reason I posted the entire - unfinished - previous response is that it was very, very late, but I didn't want to miss the post, or detract from its meaning. I realise now that the post is confusing on the point that you highlight and I apologise unreservedly. Though, if you take out the bracketed comments it makes more sense.

Quote.
I didn't think that O2 was radiatively active. Besides, ozone is measured in parts per billion, so a reduction in ozone implies a tiny tiny change to the composition of the main atmospheric molecules.
EOQ.

As far as I am aware, the absorption spectra for O, O2 and O3 are the same. They all react with very high frequency radiation (UV frequencies plus). The absence of ozone (O3) in the stratospheric 'ozone layer' at our polar regions suggests that radiative interaction with O3 can no longer occur in the stratosphere within these regions at the 'ozone layer' altitude.

There also seems to be a stratospheric 'cooling' process at altitudes where O3 has disappeared (IPCC). This also suggests that radiative frequencies that previously interacted there no longer interact. However, I expect that this solar irradiation still continues to manifest itself and strikes deeper into the atmosphere to interact at a lower altitude (the need for people to now use a higher 'sun block factor' suntan lotion within these regions supports this).

I don't see the "composition of the main atmospheric molecules" to be an issue here, only the altitude at which "UV frequencies plus" interact with the atmosphere because the lower the interaction altitude, the greater the effect to the planet's surface. However, as I have said, this is conjecture on my part.

I don't see where the IPCC take an account of this 'transference of effect'. Other than to declare that the stratosphere is cooling. Do you?

quote:

I don't see where the IPCC take an account of this 'transference of effect'. Other than to declare that the stratosphere is cooling. Do you?

I do know that some models do include proper ozone representation (I have been peripherally involved in helping someone set up the ozone files correctly in their model).

I suspect ozone changes may not be included in the IPCC model projections because we aren't sure how it will change over the next 100 years. This is justified because it is thought to be a small effect. There is a lot less air in the stratosphere so it takes a lot less to warm or cool it - if the effect is "transferred" to lower levels, it may not be noticeable.

Incidentally, stratospheric cooling is also caused by the increase in greenhouse gases.

The plot of absorption here suggests that O3 absorbs in the near UV whereas O2 absorbs only in the far UV (where there isn't much solar irradiation):

www.atmos.washington.edu/1998Q4/211/absorption.gif

Please forgive me for butting in.

Suricat,

I thought O3 absorbs at a peak of 240-280nm. Seee here.

And the solar spectrum you gave shows radiance levels at that wavelength over a 1000 times down on the visible light radiative peak.

How much incoming radiation do you propose as a proportion of visible incoming?

Or have I totally misunderstood?



Steve M,

You're right, this shows the cooling is mainly due to the enhanced greenhouse effect.

And there's more fiddling:

Swedish Scientist Accuses UN's IPCC of Falsifying Data and Destroying Evidence

Also:
IPCC Response to the Briffa Deletions

quote:

Originally posted by CobblyWorlds:
Steve M,

You're right, this shows the cooling is mainly due to the enhanced greenhouse effect.

Here we go ('cooling due to greenhouse effect'? - talk about an oxymoron) - I was expecting this eventually, CO2 causes global cooling?

quote:

Here we go ('cooling due to greenhouse effect'? - talk about an oxymoron) - I was expecting this eventually, CO2 causes global cooling?

Wow! You really are cynical. The prediction of stratospheric cooling is key evidence in favour of increased greenhouse gases being the cause, since a warmer sun would be expected to warm both the stratosphere and troposphere.

As to the links in your previous post, it is ironic that now the IPCC review comments (second link) have been published we can see that the Swedish expert on sea-levels and alleged IPCC reviewer (first link) did not apparently find the time to comment on the sea level chapter. So he shouldn't feel upset if it doesn't reflect his views.

As to sea-level rise, there is a massive amount of scientific debate as to the measurements, and the causes, since decent satellite measurements have only been available since 1993. It looks to me that his figure of 1.1mm per year over the last century is pretty close to the consensus view of 1.7mm+/-0.5mm.

Steve_M

quote:

The prediction of stratospheric cooling is key evidence in favour of increased greenhouse gases being the cause, since a warmer sun would be expected to warm both the stratosphere and troposphere

At best this is evidence that any global warming upto 1998 (when it stopped) was not a direct effect of a warmer sun.

quote:

At best this is evidence that any global warming upto 1998 (when it stopped) was not a direct effect of a warmer sun.

Firstly, the stratosphere is still cool and the troposphere still warm, so the continuing warmth is the result of GHGs.

Secondly global warming did not stop in 1998. I'd have thought you'd understand enough by now to know that there is a lot of energy in the ocean such that a large El Nino can have a big impact on atmospheric temperatures as is what happened in 1998. And if it stopped in 1998 it started again in 2001.

Thirdly, see page 763 of Chapter 10 of the IPCC AR4 WG1 report. Many of the model simulations show short term ups and downs in the temperature trend on top of the long term ups, so a few years of similar temperatures are not unexpected.

ipcc-wg1.ucar.edu/wg1/wg1-report.html

Hello again Steve,

The Science Forums has suddenly gone downhill, just as I praised it!

Have I shown you Wild et al "Impact of global dimming and brightening on global warming"?

It presents a reasonable explanation for the change of trend in Land Mean Temperatures in the 1980s, and the apparent cessation of the trend in diurnal range in the 1980s.

So the diurnal range issue now seems to be back on the table as evidence of the Greenhouse effect (which should cause more night-time heating than daytime).

In the daytime insolation dominates, at night it's the rate of heat loss by radiation. So after the early 1980s reduced levels of aerosols caused a daytime warming trend that hid the trend in diurnal range.

They also find:

quote:

In the majority of the surface solar radiation records from GEBA we find that, despite the widespread trend reversal from dimming to brightening, the amount of solar radiation at the surface has not reached the 1960 level. Despite the fact that surface insolation at the turn of the millennium is rather lower than in the 1960s, land surface temperatures have increased by 0.8degC over this period (Figure 1). This suggests that the net effect of surface solar forcing over the past decades cannot be the principal driver behind the overall temperature increase, since over the past 40 years, cooling from solar dimming still outweighs warming from solar brightening.

Rather, the overall temperature increase since the 1960s can be attributed to greenhouse forcing as also evident in the BSRN data outlined above.

Thus, speculations that solar brightening rather than the greenhouse effect could have been the main cause of the overall global warming over the past decades appear unfounded.

And the sting in the tail:

quote:

We therefore estimate that, over the past decades, the greenhouse forcing alone has enhanced land surface temperatures by certainly
more than 0.20degC per decade{what actually happened}, but unlikely much more than 0.38degC per decade.

PS You have been busy learning!

Steve_M.

Quotes.
1. Incidentally, stratospheric cooling is also caused by the increase in greenhouse gases.

2. Firstly, the stratosphere is still cool and the troposphere still warm, so the continuing warmth is the result of GHGs.
EOQs.

Actually Steve, the top of the troposphere and tropopause are both colder than most of the stratosphere. After the tropopause temperatures begin increasing with altitude. I doubt that Earth's back radiation causes this, it's more likely to be a component of solar radiation acting on a 'banded gas'.

quote:

Originally posted by Steve_M:
Wow! You really are cynical.

Yes I am where AGW is concerned.

quote:

Originally posted by Steve_M:
The prediction of stratospheric cooling is key evidence in favour of increased greenhouse gases being the cause, since a warmer sun would be expected to warm both the stratosphere and troposphere.

Where? Where is your evidence?

quote:

Originally posted by Steve_M:
As to the links in your previous post, it is ironic that now the IPCC review comments (second link) have been published we can see that the Swedish expert on sea-levels and alleged IPCC reviewer (first link) did not apparently find the time to comment on the sea level chapter. So he shouldn't feel upset if it doesn't reflect his views.

Could be because he regards them as the political unscientific bunch of alarmists that wouldn't listen to his comments anyway if he were to present them - did you notice how many comments are rejected - clearly not.

APL,

Clearly you have never been in any kind of review process - the vast majority of comments presented in every process review I've been involved in at work are rejected.


Neglecting albedo for the moment, there are 2 gross directions of radiative flux for the Earth, shortwave(SW) in, longwave(LW) out.

Increase in Solar Irradiance.
More SW and more LW flux through the whole atmosphere - so all of the atmosphere warms.

Increase in greenhouse effect.
Unchanged SW, reduced LW flux. So although the strato still gets some energy from the SW, as the greenhouse effect reduces outgoing LW, there's a net drop in available energy. So the strato trend is cooling against the tropo's trend of warming.

quote:

Originally posted by CobblyWorlds:
APL,

Clearly you have never been in any kind of review process - the vast majority of comments presented in every process review I've been involved in at work are rejected.


Neglecting albedo for the moment, there are 2 gross directions of radiative flux for the Earth, shortwave(SW) in, longwave(LW) out.

Increase in Solar Irradiance.
More SW and more LW flux through the whole atmosphere - so all of the atmosphere warms.

Increase in greenhouse effect.
Unchanged SW, reduced LW flux. So although the strato still gets some energy from the SW, as the greenhouse effect reduces outgoing LW, there's a net drop in available energy. So the strato trend is cooling against the tropo's trend of warming.

Oh and the cooler stratosphere won't lead to a cooling of the troposphere - because?

You make it sound so simple when it isn't.

Cobbly

quote:

Increase in greenhouse effect.
Unchanged SW, reduced LW flux. So although the strato still gets some energy from the SW, as the greenhouse effect reduces outgoing LW, there's a net drop in available energy. So the strato trend is cooling against the tropo's trend of warming

On the site Real Climate Gavin Schmidt makes the folowing statement in response to comment 2.2 in the attached ref

http://www.realclimate.org/index.php?p=58

"The observed lower stratosphere trend is mainly due to decreasing ozone. Further up, and over the longer term, greenhouse gas changes are likely to be dominant. - gavin"

You make it sound like it's fact and happened.

quote:

Originally posted by APL:

quote:

Originally posted by CobblyWorlds:
APL,

Clearly you have never been in any kind of review process - the vast majority of comments presented in every process review I've been involved in at work are rejected.


Neglecting albedo for the moment, there are 2 gross directions of radiative flux for the Earth, shortwave(SW) in, longwave(LW) out.

Increase in Solar Irradiance.
More SW and more LW flux through the whole atmosphere - so all of the atmosphere warms.

Increase in greenhouse effect.
Unchanged SW, reduced LW flux. So although the strato still gets some energy from the SW, as the greenhouse effect reduces outgoing LW, there's a net drop in available energy. So the strato trend is cooling against the tropo's trend of warming.

Oh and the cooler stratosphere won't lead to a cooling of the troposphere - because?

You make it sound so simple when it isn't.

No it's not simple, but it has been observed.

The largest effect over the whole stratosphere seems to be the enhanced greenhouse effect. See the GFDL here.

When I look at the areas bounded by the red and blue trace (Ozone + GHGs) as opposed to the area between the blue trace and the zero axis (Ozone only), the former is the greatest.

APL.

Quote.
Oh and the cooler stratosphere won't lead to a cooling of the troposphere - because?
EOQ.

Do you give enough weight to the O3 'SW filter' depletion scenario?

The main 'heating' we observe in the stratosphere is generated from SW solar insolation. O3 is a SW 'converter/generator' to LW in that region and due to its depletion doesn't interact to the same extent as it did before its depletion. Part of the result of O3 depletion is that less SW interacts in the stratosphere to generate 'heat', and another part of the result is that more SW is unfiltered to continue on to the Earth. The 'bias' is changed, but the total solar SW irradiation isn't.

I also find it extremely coincidental that UV (a short-wave component) is far more penetrative through water and ice than visual light, or IR. Especially so when we also see accelerated movement of glaciers.

quote:

Originally posted by suricat:
Do you give enough weight to the O3 'SW filter' depletion scenario?

The main 'heating' we observe in the stratosphere is generated from SW solar insolation. O3 is a SW 'converter/generator' to LW in that region and due to its depletion doesn't interact to the same extent as it did before its depletion. Part of the result of O3 depletion is that less SW interacts in the stratosphere to generate 'heat', and another part of the result is that more SW is unfiltered to continue on to the Earth. The 'bias' is changed, but the total solar SW irradiation isn't.

I also find it extremely coincidental that UV (a short-wave component) is far more penetrative through water and ice than visual light, or IR. Especially so when we also see accelerated movement of glaciers.

Not at this time primarily because too little is known, it isn't a clear path from stratospere to the earth's surface and the troposphere would need to be taken into consideration. So yes more UV gets past the stratosphere but gets stopped in the troposphere which is likely to produce more ozone.

Also do not overlook fundamental thermodynamics which is discussed in the following links which are taken from Son of Mulders post above.

Funny I tried to also post Son of Mulders link with these links earlier but was blocked.

I couldn't put the links on the page but they are those on comment 10 here

APL.

I can see now why my debut to this chat forum was met with some animosity. At the risk of inviting more angst, I'll restate that my disciplines come from an engineering background (Universal Millwright and MV tec). I haven't read through all three of those links, but what I have read through makes full sense and I concur with the basic content (though I usually try to avoid geocities sites for reasons of security and acceptability (this is probably also the reason you were blocked)).

If you wish to ostracise me now, just ask me to leave your thread.

However, I do understand the thermodynamics involved and they do not apply in this case. Unless cloud, other aerosols, or particulates diffuse the 'line of sight' UV insolation, the UV strikes ground zero. It does, sunburn levels are a coarse measure of this and it has increased. I'll say no more without your acceptance.

quote:

Originally posted by suricat:
However, I do understand the thermodynamics involved and they do not apply in this case. Unless cloud, other aerosols, or particulates diffuse the 'line of sight' UV insolation, the UV strikes ground zero. It does, sunburn levels are a coarse measure of this and it has increased. I'll say no more without your acceptance.

Thermodynamics always applies. Fundamental thermodynamics are simply that a hot body will always transfer heat to a cold body until equilibrium is reached and cannot be stopped although it can be slowed. In your example the hot body is the sun the cold body the earth thermodynamics applies.

So if the stratosphere is cooler than the troposphere fundamental thermodynamics will dictate that the stratosphere will cool the troposphere regardless of what's in the way to slow the transfer.

Also if the atmosphere consisted of super-insulators, as is often attributed wrongly to CO2, then there would be a lag in the time it takes to dissipate the heat such that we would not experience the rapid changes in temperature that we do on a daily basis, because the heat transfer would be slowed (but not stopped) between the sun and the earth, and the earth and space. This is an simplistic view I know but never-the-less thermodynamics still applies.

quote:

So if the stratosphere is cooler than the troposphere fundamental thermodynamics will dictate that the stratosphere will cool the troposphere regardless of what's in the way to slow the transfer.

That's a to simplistic argument. The atmosphere has a particular temperature profile dictated by radiation, convection, properties of water, etc. processes. It is warm at the bottom, cold in the middle and then starts getting warmer again. There is nothing in the laws of physics that says the temperature will inevitably even out, after all this basic structure has probably applied for a few billion years. Equally, there is nothing in the laws of physics that stops a constituent or dynamical change from changing the temperature profile in some way.

I think the "insulator" argument is too simplified for the atmosphere, but if applied to your loft, adding more insulation results in your loft being cooler. But your loft does not "cool" your