> I'm more optimistic.
Nothing wrong with this. The issue is that, unfortunately, physics cares not one bit about optimism, aspirations or what we might wish for. It just doesn't care.
I have not seen a single purported solution to date that passes the physics test. Not one. Most don't even pass the economics test.
I'll give you a simple example without numbers. One proposal is to seed the oceans with iron powder. Let's ignore the mechanism for now, it's irrelevant.
Anyone who knows anything about manufacturing will immediately zero-in on the hard and cold reality that producing such a material is an incredibly dirty and energy-hungry process. Producing it at a rate of billions, tens of billions or hundreds of billions of tons per year would likely require more energy than most nations can spare.
This would mean that hundreds to thousands of new power plants would have to be built. If they are not nuclear, then they burn something. Wind and solar? They are not clean at scale, but sure. No matter what you do, you will be producing CO2 (and other substances) at an alarming rate just to produce the material. I don't even want to think about the waste product.
Of course, we also have to ask what we would do to the planet in terms of the incremental mining necessary to obtain all of the raw material this would necessitate.
So, after all of that, you now have what you are after, and then you have to transport and deliver it. Transporting billions of tons of iron dust at a planetary scale would engage millions of ground, air and sea vehicles, all burning oil derivatives at a, well, planetary scale rate. Millions to billions of trips would have to be made to "paint the oceans" with this stuff. We might not have enough vehicles to do this, which means we'll have to manufacture them, which comes with environmental consequences.
The CO2 and pollution (because none of these processes are clean) this would produce is far more likely to make matters worse than to actually solve any problem.
And then you have the reality that a planetary-scale problem isn't going to be affected in seven days. Which means that the above-noted hypothetical might require ten, twenty, fifty or a hundred years of constant effort before anything even registers.
We are far more likely to kill all life on earth than to fix the planet.
None of the purported solutions I have ever seen engage in any realistic full-process analysis, not even at a superficial level. If you fire-up Excel and throw some numbers at these things it quickly becomes very obvious that they all exist within a range that lies between nonsense and hubris. What's brilliant is that they are all taking advantage of nice grants and research money, which, from one perspective, makes it genius. I can think of a few other imaginary things on this planet that make tons of money, one of them has a whole city built around it!
Believe it or not, my view isn't pessimistic at all. I am simply trying to make people think and understand that we are being sold a fantasy. Once that is well understood we need to focus on the reality of the matter. Which means we need to develop technology and programs aimed at living with this reality rather than living under the delusion that we can change a planetary scale problem.
I also urge anyone who cares to understand the truth to go out and buy a CO2 meter to then explore their environment. If you do that, what you will discover is that we actually live in an environment ranging between about 650 and 1100 ppm. And this has likely been the case for centuries. The most immediate observation being that humanity has obviously not turned into shapeless blobs of gelatin. In other words, someone needs to explain the "sky is falling" theory given the realities of what we actually experience in our homes, apartments, offices and cars every day of our lives.
My optimism is based on the idea that we will eventually understand we are being lied to due to both political and financial interests. At some point the "emperor has no clothes" scenario has to play out. And, when that happens, we will change our focus to more productive pursuits having to do with making life better while letting the planet do what it has to in order to manage the ecosystem --as it has for billions of years.
We can live with this at the micro level (because, at a planetary scale we are insignificant) while letting the macro level function as it does.
One thing is certain: None of us are going to see any change of note. Changes at a planetary scale are measured in tens of thousands of years, not decades.