Greenhouse Gasses? Sorry - not convinced...
Greenhouse Gasses? Sorry - not convinced...
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kVA

Original Poster:

2,460 posts

235 months

Sunday 27th December 2009
quotequote all
I was pondering this in the bath this morning (nice and deep and using LOTS of hot water biggrin)

The way a greenhouse works is by allowing the heat/light through, but not letting air circulate to cool it down again... If you took the sides out of a greenhouse, the temperature under the glass would be the same as that on top of the glass - right?

OK, so if we now extend that to its infinite conclusion and wrap the entire Earth's atmosphere in glass, there will be no change in the temperature below the glass anyway (as the only temperature transfer between Earth and space is via light emission). So, can someone tell me how a gas does something that glass doesn't?

The only way you could create a difference above and below the glass is by having polarising glass - that allows light/UV to pass in one direction, but blocks reflected light/UV rays. But how do you get a polarising 'gas'??? If so-called 'Greenhouse Gasses' do somehow have a polarising effect, I have two more questions for the physisists...

1) Could we not somehow reverse the polarity of the gas, to reverse the effects of global warming as required?

2) Why don't we use these 'polarising' gasses to make double glazing / greenhouses / fridges and freezers / heating systems / etc... more efficient?


One final, related thought... I saw a documentary recently that showed how a single volcanic eruption lowered temperatures in the USA and Europe by 0.5 degrees, purely because the dust and ash cloud created reflected the sun's heat/light: Why don't we return to burning fuels that create smoke and counter the effects of global warming that way?

PS. I should add that I don't believe that the planet IS warming anyway - cooling for the last 12 years, an increase in Antarctic ice, Polar Bear population gone from 5,000 to 25,000 in 50 years, and it's bloody cold outside, tell me otherwise wink

PPS Sorry if this has been said before, but I don't have time to read the 300 odd pages of existing MMGW threads!

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
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Yes spot on there are a lot of long climate threads, and now one more wink

But not long as yet smile

Have a look at this but maybe not in the bath as a laptop might not like the environment and a print out might get soggy biggrin

Falsification Of The Atmospheric CO2 Greenhouse Effects Within The Frame Of Physics


deeps

5,432 posts

271 months

Sunday 27th December 2009
quotequote all
kVA said:
1) Could we not somehow reverse the polarity of the gas, to reverse the effects of global warming as required?
Afaik, greenhouse gas (mainly water vapour) absorbs and radiates infrared radiation in all directions including out to space.

Scientist D.Archibald said:
The effect of carbon dioxide on temperature is logarithmic and thus climate sensitivity decreases with increasing concentration. The first 20 ppm of carbon dioxide has a greater temperature effect than the next 400 ppm. The rate of annual increase in atmospheric carbon dioxide over the last 30 years has averaged 1.7 ppm. From the current level of 380 ppm, it is projected to rise to 420 ppm by 2030.
The projected 40 ppm increase reduces emission from the stratosphere to space from 279.6 watts/m2 to 279.2 watts/m2. Using the temperature response demonstrated by Idso (1998) of 0.1°C per watt/m2, this difference of 0.4 watts/m2 equates to an increase in atmospheric temperature of 0.04°C.
http://westinstenv.org/wp-content/Solar_Arch_NY_Mar2_08.pdf


kVA said:
One final, related thought... I saw a documentary recently that showed how a single volcanic eruption lowered temperatures in the USA and Europe by 0.5 degrees, purely because the dust and ash cloud created reflected the sun's heat/light: Why don't we return to burning fuels that create smoke and counter the effects of global warming that way?
Think of all that horrible thick pea soup. We're lucky now that thanks to fossil fuel burning our atmosphere is the least polluted it's been for centuries.

As you say though, we should be very thankful for global warming, we're currently having near record breaking low temperatures across Europe, just imagine how cold it would be without it laugh



Edited by deeps on Sunday 27th December 17:32

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
quotequote all
deeps said:
kVA said:
1) Could we not somehow reverse the polarity of the gas, to reverse the effects of global warming as required?
Afaik, greenhouse gas (mainly water vapour) absorbs and radiates infrared radiation in all directions including out to space.

Scientist D.Archibald said:
The effect of carbon dioxide on temperature is logarithmic and thus climate sensitivity decreases with increasing concentration. The first 20 ppm of carbon dioxide has a greater temperature effect than the next 400 ppm. The rate of annual increase in atmospheric carbon dioxide over the last 30 years has averaged 1.7 ppm. From the current level of 380 ppm, it is projected to rise to 420 ppm by 2030.
The projected 40 ppm increase reduces emission from the stratosphere to space from 279.6 watts/m2 to 279.2 watts/m2. Using the temperature response demonstrated by Idso (1998) of 0.1°C per watt/m2, this difference of 0.4 watts/m2 equates to an increase in atmospheric temperature of 0.04°C.
That's interesting to read as my own 'believer paradigm' radiative forcing calculation on a PH thread fag packet got 0.05 deg C, and these are both unavoidably over-estimates.

deeps said:
As you say though, we should to be very thankful for global warming, we're currently having near record breaking low temperatures across Europe, just imagine how cold it would be without it laugh
Buy Damart and/or find appropriate bodily warmth to share wink



chris watton

22,547 posts

290 months

Sunday 27th December 2009
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Well, I’ve been watching (intermittently) the excellent Dogfights series on one of the History channels today, and every advert break had a ‘save/adopt a polar bear’ ad from the WWF on – saying how polar bears are in danger due to Co2 and global warming!

I have read in many places (including here), that bear populations have been increasing, in no small part due to us not hunting them into extinction. If this is true, why are they allowed to air adverts for our money that are based on such blatant lies?

Have we been so socially brow beaten and subliminally conditioned by the left (and let’s not forget big business making huge profits from this) over the past decade so as not to realise that 2+2=4, and not 5, as they’d like us to believe?

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
quotequote all
I got the same with Star Trek Voyager yesterday and Deep Space Nine today. What an exciting couple of afternoons that was wink

You could complain to the ASA: if I did so they would hit 'send' and release standard TB reply 'foxtrot oscar' grumpy

They seem to ask the relevant government department for the 'official' view then simply buy into it.

Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
kVA said:
The way a greenhouse works is by allowing the heat/light through, but not letting air circulate to cool it down again... If you took the sides out of a greenhouse, the temperature under the glass would be the same as that on top of the glass - right?
I thought that it was more to do with the wavelngth of light changing as it came through the "greenhouse" medium - glass in a genuine greenhouse or a particular gas in the atmospheric greenhouse effect.

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
quotequote all
An actual greenhouse gets hot inside as quickly as it does because total enclosure even with a glass roof prevents convection losses.

Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
But there is a wavelength change too, isn't there?

There is one planet where the greenhouse effect is the main climate driver - Venus.

s2art

18,942 posts

283 months

Sunday 27th December 2009
quotequote all
Eric Mc said:
kVA said:
The way a greenhouse works is by allowing the heat/light through, but not letting air circulate to cool it down again... If you took the sides out of a greenhouse, the temperature under the glass would be the same as that on top of the glass - right?
I thought that it was more to do with the wavelngth of light changing as it came through the "greenhouse" medium - glass in a genuine greenhouse or a particular gas in the atmospheric greenhouse effect.
Common name but different physics. Real greenhouses work differently than the 'greenhouse effect'.

Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
s2art said:
Eric Mc said:
kVA said:
The way a greenhouse works is by allowing the heat/light through, but not letting air circulate to cool it down again... If you took the sides out of a greenhouse, the temperature under the glass would be the same as that on top of the glass - right?
I thought that it was more to do with the wavelngth of light changing as it came through the "greenhouse" medium - glass in a genuine greenhouse or a particular gas in the atmospheric greenhouse effect.
Common name but different physics. Real greenhouses work differently than the 'greenhouse effect'.
Why is it called the "greenhouse effect" then?

s2art

18,942 posts

283 months

Sunday 27th December 2009
quotequote all
Eric Mc said:
s2art said:
Eric Mc said:
kVA said:
The way a greenhouse works is by allowing the heat/light through, but not letting air circulate to cool it down again... If you took the sides out of a greenhouse, the temperature under the glass would be the same as that on top of the glass - right?
I thought that it was more to do with the wavelngth of light changing as it came through the "greenhouse" medium - glass in a genuine greenhouse or a particular gas in the atmospheric greenhouse effect.
Common name but different physics. Real greenhouses work differently than the 'greenhouse effect'.
Why is it called the "greenhouse effect" then?
Merely because of the similarity of the two effects, both cause some warming.

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
quotequote all
Eric - yes the radiant heat going in will in the round be of a shorter wavelength compared to the radiant heat going out - due to the surface of the Sun (and subject to atmospheric transparency) being hotter than the bench supporting a tray of young tomato plants, or the greenhouse floor. Also ordinary glass is more opaque to infrared than visible light - which is where the radiation part of the greenhouse effect arises - and the visible range is where the Sun's spectral peak is. However glass will get hot and conduct heat to the outside. Convection remains a big part of garden greenhouse science.

The roof thing is probably partly where the convection effect is misapplied to greenhouse gases and the 'greenhouse gases trap heat' misapplication arises, this is an error as gases don't trap heat.

In the case of Venus, as you know it's considerably closer to the Sun than we are and also in the past there seems to have been a lot more sulphur dioxide than there is now, together with water vapour (both now largely dissociated with bits rearranged) this got the temperature up nicely, more than carbon dioxide could ever do in its own; it's a weak greenhouse gas.

Edited by turbobloke on Sunday 27th December 18:14

Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
I'm certainly not arguing the case for MMGW, but the "greenhose effect" was, as far as I always knew, was so called becaue it worked in a similar way to a traditional greenhouse.

I can see that lack of circulating air currents will contribute to the warmth inside a greenhouse, but the wavelngth change is a factor too.

turbobloke

117,219 posts

290 months

Sunday 27th December 2009
quotequote all
Based on the content-quality-over-source criterion, this isn't from the Royal Sorcery - probably an advantage - but is worth reading in terms of a section or two:

Click

One thing we can get out of the way immediately is that it doesn’t work in the same way as a greenhouse. There used to be a theory, dating back to Joseph Fourier in 1824, that visible radiation could enter through the transparent glass, but because glass is opaque to infrared, when it is re-emitted it gets trapped. Fourier proposed that gases in the atmosphere could act the same way. This theory was proved wrong for actual greenhouses in 1909 by Professor Wood of John Hopkins University. An experiment comparing a pane of glass to a pane of crystallised rock salt (Sodium Chloride) which is totally transparent to infrared found no difference in temperature. In fact, greenhouses work by preventing convection, a mechanism that is of course impossible to freely floating CO2.

Ref Wood, R. W. (1909). "Note on the Theory of the Greenhouse", The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Vol. 17, pp. 319-320.

Neither Jones nor Mann got to peer review it wink

However, this idea that heat is “trapped” in the atmosphere by absorption by CO2 has persisted. While it is now more-or-less accepted that greenhouses don’t work this way, what isn’t so well known is that neither does the Greenhouse Effect.

The author gets my vote with the wrong wrong wrong call on 'gases trap heat' misdirection, at which point carry on, realising that the penultimate paragraph misses out a few minor issues (referring to the data for one) and the rest isn't perfect but also that the final paragraph is spot on - or refer back to my earlier posted link:

http://icecap.us/images/uploads/Falsification_of_C...


Edited by turbobloke on Sunday 27th December 18:36

deeps

5,432 posts

271 months

Sunday 27th December 2009
quotequote all
turbobloke said:
Based on the content-quality-over-source criterion, this isn't from the Royal Sorcery - probably an advantage - but is worth reading in terms of a section or two
I thought this comment was interesting by the same guy...

But yes, time of day does have an effect. The simplistic model I give here averages all of that out, but there are many short term effects depending on day/night, sunny/cloudy, wet/dry, summer/winter, etc. that cause complex variations around that average. Weather, basically.

For example, on windless nights the heat supply to the surface stops and the air can cool enough that convection ceases. Then you get what is called an “inversion”, warm air on top of cold, and heat transfer is mainly by radiation. In the bottom few hundred metres of air, the IR effects dominate, although above that it’s usually still convective. If you block the solar input for long enough (like during the dark polar winters) the adiabatic lapse rate can disappear entirely, with an inversion all the way up.

And the lapse rate varies, the tropopause rises and falls and varies with latitude, and a hundred other complexities intervene. Which is another reason why it is so grossly misleading to describe the physics as simple and uncontroversial.


Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
Intersting stuff - are we saying the greenhose effect doesn't exist - anywhere - especially in greenhouses?

I'm keen to learn.

kVA

Original Poster:

2,460 posts

235 months

Sunday 27th December 2009
quotequote all
Eric Mc said:
Intersting stuff - are we saying the greenhose effect doesn't exist - anywhere - especially in greenhouses?

I'm keen to learn.
Well, if someone in the Highlands of Scotland would like to try growing tomatoes underneath a piece of glass, with no sides, then I guess we'll see... My money is on there being no discernible 'greenhouse effect' and some dead tomato plants wink

All this scientific hypothesis and big words are no substitute for a little, easy to understand, experiment...

Eric Mc

125,680 posts

295 months

Sunday 27th December 2009
quotequote all
You'll probably have the Royal Society for the Prevention of Cruelty to Tomatoes on your back.

mybrainhurts

90,809 posts

285 months

Sunday 27th December 2009
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Eric Mc said:
You'll probably have the Royal Society for the Prevention of Cruelty to Tomatoes on your back.
Why's he got tomatoes on his back...?