Oh look wood burners cause global warming.

[Terry Fields]

With apologies to Brian Gaff; I was complaining about those who could bottom-post but choose, like the toddler having a tantrum, to make their presence felt in a destructive manner.

[dennis]

They probably do it to wind you up.

bottom-post but choose, like the toddler

[Java Jive]

No.

Water vapour is being constantly recycled. Hence any local increase from you or A N Other burning or seasoning green wood will soon be gone.

Exactly, if CO2 or other forcing mechanism heats up the world, the increased water vapour taken up from the oceans will amplify the original warming effect. It's a positive feedback system.

[Terry Fields]

For the sake of scientific accuracy, forcing mechanisms can also be negative.

See, for example, diagram 20:

while this reference promotes black carbon aerosol from its previous level of understanding of 'very low' to presumably something higher, and elevated its effects accordingly, the overall effect of aerosols remains at a strongly negative level of a magnitude that equals or exceeds those of halocarbons, N2O, CH4, and CO2 combined. See, for example, diagram 20 above.

[Terry Fields]

LOL

[Terry Fields]

Sorry, that should read

[harry]

ious level of understanding of 'very

, the overall effect of aerosols remains

of halocarbons, N2O, CH4, and CO2

I didn't know there was any laughing gas in the atmosphere.

[polygonum]

level of understanding of 'very

the overall effect of aerosols remains

halocarbons, N2O, CH4, and CO2

Please, please, save the internet from overload, stop posting what you didn't or don't know.

[Terry Fields]

The Met Office know everything there is to know about positive forcing mechanisms, and if they say that N2O is on the list how could anyone deny it.

The science is settled, you see.

[dennis]

Yes its a positive feedback system that doesn't run away. So its not very positive at all is it?

So despite it being a far better greenhouse gas than CO2 something keeps it in check. Probably the same thing that keeps CO2 warming in check. Someday the climate scientists will tell us what it is, well maybe if they are honest.

[The Natural Philosopher]

Hint: the white stuff falling out of the sky may have something to do with it. Water vapour may be a greenhouse gas, in terms of keeping nigh time temps from dropping, but by day it has this nasty habit of rising in hot air columns and forming white fluffy stuff that is full of actual water, which shows that it has actually lost lots of heat to space and or adiabatic cooling. And of course clouds look white from above because they are reflecting energy from them, so they act as sun screens.

In short water vapour is actually *overall* a massive NEGATIVE feedback system.

It is the worlds thermostat. hotter oceans = more rain and clouds somewhere else = more heat loss and hence falling temperatures..

However there's a massive decadal lag in the system and oceans take a LONG time to warm up.

Which is why as the world starts to cool there a lot of heavy rain around disturbing normal weather patterns (in so far as weather is ever normal).

The only reason they ever invented water vapour as a positive feedback mechanism is imply because the CO2 model didn't fit the data without it, so they needed and 'amplifier' and because all they understood - and that badly - was greenhouse gases - they had to shove that in as an 'explanation'.

Whereas its far more likely that anything that modulates clouds will have an infinitely higher impact than CO2.

Which is why Svensmark is interesting.

[Martin Brown]

mechanisms, and if they say that N2O is

It is a polyatomic species and is present in the atmosphere in measurable quantities roughly about 330ppb at present. It hasn't risen all that much since pre industrial times unlike methane which has.

The science of what makes a greenhouse gas is well settled. The measurement of its concentration these days is trivial.

Here is a reasonable scientific explanation of the science.

lying dittoheads pretend that there is no AGW.

[Martin Brown]

So long as the total loop gain is less than 2 that will always be the case. In other words modest positive feedback is perfectly safe.

1 + a + a^2 + a^3 ... = 1/(1-a)

The value for 1/(1-a) is disputed but likely between 3 and 4.

The reality is a bit non-linear since water vapour pressure rises faster with increasing temperature but not by enough to worry about until you start to boil the equatorial oceans. That is a long way off - but making some previously fertile places too hot for plants to grow might happen sooner than you think. Australia is finally waking up.

Water vapour is kept in check by the air temperature and supersaturated vapour pressure of water forming clouds. No such constraints exist for CO2 except possibly in the coldest extremes of a polar winter.

The scientists *are* honest it is the politically motivated fossil fuel lobby in America that is packed with liars and deniers for hire.

[Terry Fields]

Ah; talking of lying....

If you look at Diagram 7-15 of your reference, you'll see it is taken from Diagram 20 of this reference:

it isn't the same, as in your Diagram 7-15 they have missed out several of the effects mentioned in Diagram 20, which in total have a negative forcing effect.

Cool, eh?

Oh, and diagram 7-17 of your reference has missed out the reflected flux.

[dennis]

I think you have a maths problem.

[Tim Streater]

Denier? We talking about stockings again?

[Tim Streater]

By this do you mean "compound"?

[Martin Brown]

No. I mean something more complicated than diatomic (two atoms).

O3 is also polyatomic but contains only oxygen atoms - but 3 of them. Most polyatomic species are compounds, but the important thing here for the physics is that they must contain more than two atoms.

By comparison O2, N2 are diatomic and have little or no absorption in the thermal band IR relevant to the Earths temperature. H2O, CO2, CH4, O3, N2O and NO2(brown gas) all have spectral lines in thermal IR band.

The important thing about polyatomic species is that there is (at least) one soft mode of oscillation with a much lower frequency than bonding energies. The one where the central atom jiggles about its mean position either parallel or perpendicular to the bonds.

For CO2

Lowest energy mode

O--C--O O-C---O O--C--O O---C-O O--O--C

Highest energy mode

O--C--O O---C---O O--C--O O-C-O O--C--O

Wagging the carbon up and down isn't so amenable to ASCII art.

[Terry Fields]

Thus giving rise to the well-understood field of IR spectrometry.

Do you have a point to make in posting the above?

[Roland Perry]

In message , at

10:28:20 on Tue, 22 Jan 2013, Tim Streater remarked:

Maybe, although their argument is pants, rather than pantyhose.