No, sorry. That's not what I meant. What the ice core data gives us as a baseline is what will happen if humanity and all of our technology leaves the planet. Let's call it 100K years for 100 ppm reduction.
This is a real baseline based on highly accurate scientific data. The first thing I did when I reached this conclusion was to try to invalidate ice core sample data. It turns out this data is extremely accurate and, I think I can say, irrefutable.
And so, this is the baseline from which, I propose, we need to evaluate any proposal that says: Eliminate X and we save the planet (fix the problem, stop climate change, etc., pick one).
In other words, I propose it proves a simple idea:
We cannot fix this problem by eliminating anything.
We can say this because we know that if eliminate humans and human technology --let's call that "everything"-- it will take 100K years to drop 100 ppm.
Every such proposal should be measured from this baseline.
Eliminate cars? Nope, you can't just do that and fix it faster than 100K/100ppm, if at all.
Eliminate cars, trucks, planes, trains and ships? Nope, that is still less than humanity evaporating. It's still, at best >100K/100ppm.
Eliminate all fossil fuels and all of the above? OK, now we are getting stilly and it still isn't going to be any less than 100K/100ppm. Because for 100K/100ppm by elimination of human sources of CO2 we have to leave the planet.
If you haven't I urge you to read the paper I linked to in my top comment. The researchers had enough and were convinced that the solution was a world-wide shift to renewables. They say so in the paper. And --thankfully-- they are also honest enough to say that they were astounded to discover that what they knew to be true was, in fact, false. We need honest scientists that are isolated from the consequences of looking at the truth of these issues.
Their conclusion, paraphrasing, was something like: Even if we switched the entire world to the most optimal and efficient forms of renewable energy (yet to be invented) atmospheric CO2 levels would continue to rise exponentially.
That is a sobering though.
As to solutions like bioengineered trees, etc. From what I've seen the main issue (other than the potential for horrific unintended consequences) seems to be that when you look at the energy and resources it would require to develop, manufacture, deploy and manage such technologies you realize they would cause more harm than good.
I don't know the answers. What I think I know is that we need to stop lying because the narratives being pushed are false and dangerous (because they prevent our scientists from working on the real problem).