‘wasted wind’)

I knew what you meant when you said ‘lean on’, but I note you’ve yet again taken a minor issue and used it to avoid answering the main one. Which was ‘what is the mechanism involved’,

Just answer the issue raised from the NASA link you posted.

Justify what?!

Simply untrue. Look at what I wrote. In context.

I've already clarified the distinction between direct and indirect aspects of greenhouse gases. You don't accept, or understand, that distinction. I'd suggest you take that up with NASA. Not me.

I only understand it as far as I have already explained. We differ on direct and indirect characterisations. I'm still not sure of your position in that regard.

The exact processes and mechanisms are beyond my current understanding.

Ah! So I don't have to be critical of my grandchildren swanning off to America for a fortnight. Mostly using up *air miles* I guess.

Interesting about the 9/11 2.0 deg. temperature drop.

Wait for the Tundra methane to get going!>

Methane breaks down very quickly.

You need to explain, or at least do some research and find out, why NASA claims only one of the greenhouse gases on its list operates ‘indirectly’.

In this:

When you scan down to the heading Water Vapour.

Which says this:

Water vapor is the most abundant greenhouse gas, but because the warming ocean increases the amount of it in our atmosphere, it is not a direct cause of climate change.”

Look at what I wrote, in context.

It’s your link, you posted it hoping to squash opposition to your point of view by bringing in the might of NASA. It didn’t work. Then you tried AI, and it returned claptrap. You *still* can’t explain why the world’s most abundant greenhouse gas doesn’t increase global warming when the quantity of it in the atmosphere increases, unlike all the other greenhouse gasses.

"I don't understand, but NASA says it, so it must be true..."

Bandar Log-ic... And argumentum ad authoritatem...

The main weapons of the New Left

Except when it needs to, to make scary climate predictions.

Spot on.

Yes, and it’s leaving its Marx on society, just as intended.

The NASA piece points to the *indirect* nature of water vapour. Additional, direct, variables impact upon the climate, creating the greenhouse effect. The second paragraph of that piece lists water vapour as a greenhouse gas. This has been explained to both of you several times.

I accept (of course) that Spike doesn't recognise the distinction between direct and indirect variables in this context. But that's the way NASA, and many others, deal with the mention of water vapour as a greenhouse gas.

Either water vapour creates global warming or it doesn't. There is no such thing as an 'indirect' variable.

Well said.

RJH is studiously ignoring the fact that NASA is claiming that:

a) there are a number of greenhouse gases

b) greenhouse gases cause climate change

c) water vapour is a greenhouse gas

d) water vapour doesn’t cause climate change on its own.

I have repeatedly asked him to state the scientific basis for this absurd position.

Of course there is. Even in social science ;-)

And I have listed, at least 3 times, 5 of them. Including water vapour.

And I have recently asked you to clarify it with NASA. Good as I am, I have nothing like the training of NASA scientists and wouldn't pretend as much. That's why I rely on their judgement.

But anyway. A bit more on this:

Water vapor acts as an indirect cause of climate change primarily through what's called a feedback mechanism rather than being a direct driver like CO2 or methane.

Here's how it works:

The Primary Process: When greenhouse gases like CO2 warm the atmosphere, warmer air can hold more moisture. For every 1°C of warming, the atmosphere can hold about 7% more water vapor. Since water vapor is itself a potent greenhouse gas, this additional moisture traps even more heat, amplifying the original warming.

Why It's Considered Indirect: Water vapor doesn't initiate climate change on its own. Unlike CO2 emissions from burning fossil fuels, water vapor concentrations are controlled by temperature rather than human activities. You can't directly increase atmospheric water vapor long-term by adding water - excess moisture simply condenses and falls as precipitation.

The Feedback Loop: CO2 and other greenhouse gases cause initial warming Warmer air holds more water vapor More water vapor traps additional heat This causes further warming, which allows even more water vapor The cycle continues, roughly doubling the warming effect

Regional Variations:

This feedback is strongest in the tropics where there's abundant moisture, and weaker in cold, dry regions like the Arctic. The effect also varies with altitude - water vapor feedback is most pronounced in the lower atmosphere.

This water vapor feedback is one of the most significant amplifying mechanisms in the climate system, making it a crucial indirect factor in climate change projections.

I defy you to repudiate a single sentence.

I accept (of course) that some scientists that question some of the water vapour notion - Lindzen, for example. But overall, scientists support the NASA position. Most scientists, it seems, except you.

Oh dear. I cant deal with such a low level of rationality

However alleged water vapour 'feed back' is triggered by ANY temperature change, not excluding increase in water vapour triggered by CO2.

And the fact is, that this type of feedback has never been demonstrated, and in particular as I wrote some time ago a study on the Pinatubo eruption shows temperature change EXACTLY as (within experimental error) as that to be expected WITHOUT such feedback ... and the went on to conclude that that proved that CO2 had produces such and such a change WITH feedback.

Its extraordinary that water vapour only feeds back when its CO2 involved, but not ant ant other time and not in the past either.

You pointed to the NASA web page to justify your views and asked if anything could be found to be wrong with it the article there.

That has now been done.

You now need to either withdraw the NASA web site link from your justification, or contact them about justifying their position.

It is not up to me to do so, as I didn’t introduce them into the discussion. I am not doing your work for you.

That’s your choice.

That’s routine knowledge.

But that’s not what you used as justification.

You have been asked repeatedly why NASA said water vapour doesn’t directly affect climate change, and now you are saying it does do so.

Can you please make up your mind as to what you are using as justification for your position on climate change.

But you said above that it does! It’s a Potent Greenhouse Gas!

But as your quote implies, there is a limit to how much water vapour the atmosphere holds. At that point water loses its claimed indirect effect. You can’t have it both ways.

So where in this doomsday scenario is the limit caused by precipitation?

You can’t have it both ways.

Fecit.

That sounds dangerously like Obama’s claptrap claim about 97% of scientists agree about global warming.

" In 2013, U.S. President Barack Obama sent out a tweet claiming 97 per cent of climate experts believe global warming is “real, man-made and dangerous.” As it turns out, the survey he was referring to didn’t ask that question, so he was basically making it up."

"The most highly cited paper supposedly found 97 per cent of published scientific studies support man-made global warming. But in addition to poor survey methodology, that tabulation is often misrepresented.

Most papers (66 per cent) actually took no position. Of the remaining 34 per cent, 33 per cent supported at least a weak human contribution to global warming. So divide 33 by 34 and you get 97 per cent, but this is unremarkable since the 33 per cent includes many papers that critique key elements of the IPCC position."

Might as well just dispense with this little nugget. As it seems to form the basis of your, and your comrade's, compound misunderstandings.

I have always maintained water vapour is a greenhouse gas. As has NASA. They keep good company.

The distinction is that, in the context of anthropogenic climate change, it's an indirect variable. Water vapour is affected by certain human created direct factors. Hence the 'anthropogenic' bit. I've given you far more detailed explanations of the direct and indirect aspects elsewhere.

I think you have a problem with this as you think the topic is context free, and readily explained with nothing more than some figures (doesn't seem to matter which) and an ability to add up. Which IMHO is mistaken. But do carry on.