Here's our disagreement: I say there's no real equilibrium. Even if there were no humans on the planet, CO2 would fluctuate; it has in the past.
If you are talking DEEP past - the earth was a lot hotter then and had far more volcanoes spewing CO2 out all the time. In fact - these volcanoes may have saved life on earth from the Snowball Earth by poking through the planet wide ice sheets and spewing greenhouse gases into the atmosphere - eventually cooking the place. The storms that resulted had such severe acid rain from all that CO2 that it melted rock!
It's all constantly varying, and not just CO2.
Yes - and they know why. There are many climate forcings, from BIG SLOW ones to smaller short ones.
EG: There's the "long" carbon cycle - with CO2 being trapped by algae life in the bottom of the ocean for millions of years, then getting caught up in a magma flow and being spewed back out a volcano. This has gradually shrunk with the slow cooling of the planet over tens of millions of years - as a general trend.
But sometimes rare volcanic events can spew more CO2 than normal - and cook the place up again.
This is not happening today, and volcanoes are about 1% of our emissions.
There's fluctuations in output from the sun, not terribly great but the sun is very big and the earth is very small.
All measured and understood by the IPCC. IF you bothered to read their reports!
At the moment discounting variations from axis wobble and when aphelion and perihelion occurs in respect to the seasons because, while these are variations, they are over long spans of time.
Milankovitch cycles help the earth COOL from where we are - not COOK into a hothouse earth!
Also - about 40% of the depths of the coolest phase of an ice age are from CO2 sources getting trapped by encroaching ice sheets!
Even with something as enormous as the wobble of our planet on it's merry way around the sun, changing the angles sunlight hits the earth, CO2 has a role!
Also discounting the predicted brightening of the sun, since that's longer term than variations due to the earth's orbit.
Yes! Agreed! So we have to be MORE careful than the dinosaurs about how much CO2 is in the air.
The sun is 2% warmer than back then! That's another long term forcing!
So is the position of the continents on the planet.
But these are such long term things that we will not notice them.
We've nearly doubled CO2 in the geological blink of an eye!
If I wanted to be extra persnickety, I'd throw in the effects of continental drift.
Ah, good. Yes. But as if we're not going to adapt to that in time, hey?

We replace a good portion of our cities every 60 years. Continental drift is in the 10's of millions of years!
But even without long them effects, it's not fixed. It just seems that way to us because we're relatively short lived.
Right - so how do the IPCC study the natural forcings and conclude CO2 is what's cooking us, hmmmmmmm?
What you term equilibrium I think of as a sort of inertia based on the time it takes for change. We know that CO2 can be naturally removed because it's happened before. It takes time, but it happened. "Tipping point" is a loaded term.
No - it's a scientifically valid concept explained in layman's terms.
Basically, climate activists are saying "It REALLY looks like there's an ice-berg ahead" to the Captain of the Titanic. It hasn't hit yet - and even if it does - there are still the lifeboats. But I'd rather save this beautiful ship!
Even if AGW turns out to be real, it's not permanently changing the thermostat settings. "Tipping point" implies otherwise.
Watch Johan!
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If you're saying "Permanently" in terms of the entire planetary life of the earth - so what? On that timescale, of course climate is not 'fixed'. Eventually the CO2 might get sucked back up, the surface of the earth might finally be repopulated with plant life - and ice ages might eventually return. But that's a LONG time away from a human civilisation point of view!
Barring the Lord's return - the sun would eventually expand and burn the earth! But that's not what we are talking about!
We are talking about the optimal way to keep both human civilisation and the biosphere intact, the way we like it, now.
People and planet.
Watch Johan.