GrahamY,
>You keep making the same mistake
It's no mistake; merely poor comprehension on your part.

I'm well aware that there's much more water than CO2 in the atmosphere, and of the cooling effect of evaporation, the warming effect of condensation, and the net cooling effects of clouds despite their warming effect under some circumstances (most significantly at night). But it is absolutely clear that water VAPOUR warms the planet overall.

Now for the important bit:
Do you understand that when the planet is warmer due to other greenhouse gases, the more vapour the atmosphere can hold (warming it further) and the longer it takes for that vapour to condense out into clouds?

>The fact that there has been no runaway global warming effect when the earth has
>been a lot warmer suggests that water vapour actually provides a negative feedback

No, it suggests that negative feedback mechanisms exist. There's a difference.
The trouble is positive feedback mechanisms exist too. The present warming is the fastest for millions of years, so while it's a good sign that negative feedback mechanisms prevailed before, it doesn't guarantee we'll be OK this time.

(tbc)

>BTW, the thermal mass of the ocean is a bit of a furphy.
No it isn't. It's a major moderating factor but it could ultimately make the problem harder to deal with, as the task appears smaller than it really is.

>It is the temperature of the oceans that controls the temperature of the earth,
Not entirely, but it's a VERY big influence.

>and if the heat was trapped in the ocean then it wouldn't be escaping into the
>atmosphere and there would be no global warming. You can't have it both ways.
STRAWMAN ALERT!

I never even claimed the heat was TRAPPED in the ocean, yet you're assuming a proposition far dumber: that it's trapped in an INESCAPABLE trap!

If you don't realise how truly idioic your strawman is, consider home insulation: it traps heat, but the heat then gradually leaks out.

Anyway, my point is that greenhouse gases are likely to be causing far more warming than we realise, because a lot of the heat is going into the ocean. This WILL cause the atmosphere to warm in future, but there is a significant time lag.

Mr Hemmings makes some fundamental mistakes concerning the flora of the planet. They are unfortunately common. Photosynthesis only occurs in the presence of light. During periods of darkness, plants revert to respiration where oxygen is taken in and carbon dioxide is excreted. In dense rain forest this additional CO2 overnight could enhance rates of growth during the following day.
I think that he may also be underestimating the oxygen produced from the phytoplanckton in the oceans. As many of my generation and even following ones were, we were told that the Amazon rain forests were the "lungs of the earth". This is quite misleading. During the 1980's the evaluation of this showed at approximately 80% of the respirable oxygen in the atmosphere comes from the oceans.
With his concern on "extensive" deforrestation around the world, that is dealt with by mhaze. However, his concern probably should go to the present practice in the US, Canada and Brazil where natural growth forests are being cleared and converted to wood chips (Biofuel) to be exported to and be burnt in UK and EU power stations as a green fuel. This practice completely fails the EIEO balance. While we have Governments endorsing such a practice, we know that there is no science in the argument.

This seems more about justifying delays in environmental actions and phasing out of fossil fuels?

Exemplified by this paragraph, with neither elaboration nor any supporting evidence:

'What is ignored is the high capital cost and life cycle considerations (meaning they are costly), the unreliability due to the vagaries of the weather, and that they are dependent on surface area for upscaling, but they are good for supplementing base line power and for niche markets. A solar farm or wind farm can only produce more electricity by increasing the area of panels or turbines'.

Population? Fertility rates are dropping much faster than predicted but the UNPD data for global population is coming under scrutiny i.e. claiming a slow fall from 2.5 to 2.2 by mid century i.e. replacement rate.

However, according to researchers Bricker & Ibbitson, Pearce, Sanyal et al. the UN is inexplicably lowering fertility in both India and China but then increasing it again, without explanation (maintains the high headline numbers)?

Not only will global population stall, Bricker & Ibbitson fear precipitous decline by mid century impacting economies, state budgets etc.

This is opposed to the Malthusian based prism Australia views population through via channeling of ZPG's Paul 'Population Bomb' Ehrlich and John 'passive eugenics' Tanton viewing (NOM inflated) 'population growth' as an existential threat ('Great Replacement' theory); good way to avoid environmental constraints on industry, especially fossil fuels related and promote white nationalism.

Malthus, the miserable preacher, was wrong on his population principles, so has Ehrlich on his predictions of catastrophe; why do Australian media and MPs keep promoting this form of white nativist eugenics on a daily/weekly basis, especially when wrong?

I just made a bet (to be assessed in five years) that China has already reached peak population 5 years early, based upon Hukou data via the SCMP; meanwhile India and most of Africa show fertility declining with commensurate increase in education, health and empowerment of women.

I somewhat disagree with a previous comment: 'There is no point to a planet without human beings'.
Had intelligent man not evolved, I am quite sure the planet would have got along just fine without him.
And, if left to itself, life is self regulating.
There is a limit to how much food can grow on the land, so naturally there is a limit to how much animal life can be sustained.
There is a balance reached between the opposing needs of plant and animal life.
Life will settle in to a regular sustainable pattern.

But the advent of intelligent man changed that.
He used his intelligence to make the land provide more food that it normally would.
He used his intelligence to keep alive those who were physically challenged or genetically doubtful.
Then these reproduced, and introduced their 'defects' in to the population.
Problems compounded.
I am not blaming intelligent man. He means well, and has done a good job overall.
But his intervention in an otherewise natural process has caused an explosion in the number of humans alive on the planet.
The real problem we now face is overcrowding.
And it is getting worse.
I am sure no one really believes the population can go on increasing as it has?
But beware! Nature has a trick up her sleeve.
It is called disease.
It can wipe out vast numbers of people.
Covid has been nibbling round the edges.
Or perhaps the contamination we produce and spread far and wide will poison our food supply.
Then our numbers will diminish rapidly.
If you come back in a hundred thousand years, there will still be life.
But, almost certainly, far far fewer human beings.
The natural processes of life, death, and rebirth, will be back in balance.

We remain waiting for "intelligent" man.
Monty Python is quite correct.