Don't take the kitchen analogy literally, that's not what an analogy is for. I won't discuss it, because it is purely a tool not a precise model of planetary-scale dynamics.

You also misunderstood my point entirely. And, BTW, don't tell people things like "that's completely ridiculous" unless you are in a position to irrefutably prove what you are saying. Also, it's rude.

Anyhow, my point is very, very simple:

If it takes in the range of 50,000 years for atmospheric CO2 to come down by 100 ppm without humanity around, any solution that claims to be able to do this a thousand times faster has a massive burden or proof equivalent to magic and divine intervention, combined.

Politicians toss around all kinds of proposals and plans that are equivalent of the famous "and then a miracle occurs" cartoon. They want to destroy entire economies just because they say so. And all of it is nonsense.

Now, let's think about what it means that it took 50,000 years for a 100 ppm drop (which is about what we need).

Well, it involved massive amounts of rain, hurricanes, cyclones as well as massive amounts of trees and vegetation growth. Please stop and think about the energy it took for, year after, year, for 50,000 years to drop so much water and grow so many trees and vegetation to capture the CO2 and drop it by 100 ppm. The scale is almost inconceivable.

Can we find a more efficient way to do it? OK, let's assume we can (which I think is a fair assumption). A thousand times more efficient? I don't have to do the math to know that even if we were 1,000x more efficient it would still require an astronomical amount of energy and resources. I would not be surprised if an improvement in efficient CO2 capture in the order of a million times better than the natural process still required so much in terms of resources and energy that it would be just about impossible.

And yet we are missing the forest for the trees. What I am talking about mostly is what the zealots and politicians are parading around. With the reality I presented, which is irrefutable --unless someone wants to challenge ice core data-- it is easy to prove how ridiculous their proposals actually are:

Switch to renewable energy sources: Nope, CO2 levels will still continue to rise exponentially. This has already been studied.

Stop coal plants: Nope, even if we left the planet it would take 50,000 years.

Outlaw all forms of petroleum-powered transportation: Nope, even if we left the planet it would take 50,000 years.

On, and on, and on.

What you are saying about blocking the sun is another one of those ideas. First of all, anyone who has spent a reasonable amount of time in aerospace and gotten into the physics of the matter understands the unbelievable amount of energy it would require to launch millions of solar shades and put them into orbit. I mean, it takes energy to create the fuel and oxidant to put into a rocket. And these processes are not clean. On top of that, that many rocket launches would only add to the problem. And then we are talking about meddling with a planetary scale ecological system that is the result of billions of years of adaptation under existing solar conditions. There is no way whatsoever to predict what could happen. Again, we could succeed at killing absolutely everything on this planet. The only people who believe simulations are those who wrote the code, for the most part we have no clue what <doing x> will produce 10 years from now, much less 50 or 100.

It's hubris to think we can actually do this when everything we touch is far more likely to cause more pollution and require hyper-planetary scales of energy and materials.

I know lots of people --politicians!-- have a lot of sunk costs and interest in not challenging --even a little-- the status quo. And so I fear we are going to do a whole bunch of really stupid things. And I can't do a thing about it. Nobody can, because that train is already on the tracks in more ways than one. In that sense and more this conversation is a complete waste of everyone's time.