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Whatever the cause, it doesn't really matter, Biden's recent behaviour is still evident and can't be disputed. If a person is driving a car erratically, it doesn't matter what caused them to do so, they need taking off the road. You find that out after.

OK I see. No, my comments were to express scepticism that the carbon cycle, especially the CO2 content of the air, was subject to homeostatic control just because plants grow faster with higher CO2 content etc. There are so many other elements: absorption of CO2 by the oceans, emission by volcanoes, the release of CO2 from plants back into the atmosphere when plants die, apart, that is, from those that get immured by geological processes, and so on and so forth. I don't believe it is self-correcting - and indeed the climate change experience strongly indicates it is not.

There are many potential states of relative long-term global stability embedded as islands within a sea of relative instability: During the Cryogenian epoch ('Iceball Earth') the planet was near fully ice covered for hundreds of millions of years whereas it was pretty well ice free for most of the Mesozoic. Hopefully we're a very long way from a tipping point towards a Venus-like climate, but that state would be remarkably stable. Much depends on the relative movements of the continental masses and, in very recent times, human activity. Both are pretty random phenomena.

The gaia hypothesis is just another word for god, which is just another word for 'we don't know yet'. What exactly are you asking? The world will spin on, despite what you do or think; such is the word of Dave... 😉

If you can get to BBC iplayer there is a most revealing set of four programmes, released in 2023 containing the most up to date picture of the story of the Earth and life on it. In particular the billions of years that passed whilst the atmousphere was too hazy for the correct wavelengths for photosynthesis to get through so the only life was not plant or animal. Also the peculiar sequence of events that occurred for the steps from a barren planet to the present very fragile balance and just how fragile that balance is. I thoroughly recommend watching these. https://www.bbc.co.uk/iplayer/episodes/p0fpwhhm/earth

No. What I said is while the carbon cycle is in near-equilibrium, that is not really "homeostasis", because that term applies specifically to biological systems with regulatory feedback. In this case I am not sure there is any regulatory feedback. We just have an equilibrium, reached at a particular level. If this were altered by increasing or reducing sources or sinks, the equilibrium would settle at a different point. I do not think there is any process to ensure the current level would be maintained.

Incidentally, Wikipedia on Gaia is a little short of a complete history. Like many ideas, Gaia was floating around many centres of learning. Lovelock just formalised it, but the idea was incorporated for instance into Conan Doyle's fictional character Professor Challenger.

Yes. but these are not the factors that lead to near-equilibrium in the carbon cycle, as there are so many other sources and sinks of carbon at work.

Not exactly, no. The second reaction does not produce sunlight. Again not exactly, no. In fact the degradation to a lower form of energy supports normal thermodynamic theory as well as evolution and other types of change.

They are, overall (though not at all in the steps by which they are carried out), one reaction scheme: a redox reaction, which can be driven "uphill" (reduction) by the energy in sunlight and "downhill" (oxidation) by thermodynamic "gravity", as it were. Just about any chemical reaction can, in principle and rather trivially, be driven in either direction, so the mere fact of this is not in itself evidence of balance. My understanding is that homeostasis refers to a stable biological state that resists being changed, as a result of some regulatory feedback. There is no such regulatory feedback implied by the reversibility of this reaction. However if you were to expand the scope of the question to look at the Earth's carbon cycle, there is a kind of balance, with carbon sources and sinks more or less in equilibrium: https://en.wikipedia.org/wiki/Carbon_cycle I'm not sure it is correct to call that homeostasis though, as many of the components involved are not biological.

„PBS Spacetime” „3 blue 1 brown”

I asked 'where' are you going to spend it... 😣