For about 500 million years there has been an overall downwards trend in atmospheric CO2. Highs and lows, yes, but a general downwards trend. It was mainly driven by the sorts of plants we have today. They sucked out the CO2 and turned it into sugars and fibres - stems and leaves - and spat out oxygen, then died and got buried. A levelling off of CO2 at around 225 - 250 ppm started about 10 million years ago and became more stabilised just after the last ice age. It started to look like the equilibrium point.
Then came the industrial revolution when we dug up the millions of years old dead plants to burn them and the incessant rise began: 250-260-270---410-420. It is still going up and at a rate last seen some 250 million years ago. The last time levels were at what they are today the temperature was between 4 and 6 ºC higher. There is a time lag between cause an effect so we do not know when those temps will hit us, but hit us they will.
We are never going to get to net zero, it is just a feelgood phrase to make us feel secure. It is actually quite dangerous (the phrase) as many people see it as a way to carry on. And even if we could at some point in the future hit net zero it is already too late. What we desperately need is negative CO2, some way to get us back to 300 ppm or thereabouts, and that's not going to happen either.
Meanwhile back at COPout 26 the legal eagles are wrangling over wording... should it be "reducing" or "lowering". Not that it matters, no country is going to go with the proposals.