> 1. Humans have managed to fundamentally alter the global climate on a timescale of about 150 years.
> 2. Humans are incapable of fundamentally altering the climate on any significant scale compared to natural processes.
> Pick one.

Please refer to my answer here, it addresses your question:

https://news.ycombinator.com/item?id=28124035

I hope you understand that it is impossible to provide a full treatment of this subject in a single comment. The comment you replied to did not answer your question. Fair enough. Thanks for raising the question. I address it in the above-linked answer to someone else.

The TLDR is simple:

We were able to do this in a few hundred years because we burned fuels (oil, coal, peat, natural gas) far more dense than the historically natural source of atmospheric CO2 increases: Forests.

The amount of biomatter that goes into making just one gallon of oil is hard to imagine. In fact, it is hard to imagine the time scale, pressure, heat and energy that goes into the process. Plants, animals, insects, all type of biomatter compressed and mutated into a black goo.

We came about and started to burn this black goo at a massive scale. Far more so than the other major CO2 producer, forest fires. And so, yes, in a few years we were able to pump an incredible amount of CO2 into the atmosphere, far more so than the natural order of things is able to deal with. And so CO2 ppm concentration increased rapidly.

On an annual basis, forest fires contribute over 13 billion tonnes of carbon, which is more our industrial processes produce. So, yes, burning stuff is what makes CO2. That's how the planet did it when we were insignificant and that's how we did it when we started to use incredibly dense fuels and burning it.

It is critically important to understand scale here. The world consumes somewhere in the order of 40 billion barrels of oil per year. If you were to translate that in to the equivalent biomass that went into creating it the number would be like fully burning every forest on the planet many once a day every day of the year, if not more.

Why is it that we cannot fix it in 150 years?

Because that process is massively more difficult.

First, it cannot be done with less energy than that which created the problem in the first place. It will be some fraction of the energy content of 40 billion barrels of oil per year.

Where is this energy going to come from? Not solar. Not wind. No way. This has already been proven. I am happy to provide you with a paper that discusses this fallacy if you are willing to read it.

Second, simple common sense. Grab several bags of flour, walk around Home Depot and fling flour everywhere. Now the manager demands to remove what you introduced into their building, shelves, products, etc. You would need a thousand people to accomplish that in anywhere near the time it took you to create the mess in the first place. You would need to expend far more energy doing so. You would also need far more resources (bags, shovels, vacuum cleaners, brushes, etc.) than the bags the flour came out of.

In other words, cleaning a mess is far more difficult than creating it.

We cannot clean this mess.

We have to talk about living with it.

To that point. Do you own a CO2 meter? You don't? Buy one and walk around with it. I have several. You are going to be surprised by what you learn.

We are being told that the sky will fall if we reach <pick a number> ppm. Your home and office environments are likely somewhere in the 650 ppm range and have been so for years, decades. Inside your car, 1,000 ppm isn't out of the question (no, not breathing into the meter). My point is that humanity has been living in >600ppm environments for decades, maybe even centuries (where old living and working conditions cleaner than today?). Guess what? We have not turned to mush. Not even close. This sky-is-falling thing, once you start to get analytical and step away from the sales pitches quickly starts to look like a huge red herring to benefit business or political objectives. Get a CO2 meter and tell me I am wrong. I am not.

To understand this subject you have to be willing to do some work. You can't just repeat what you are being told. You have to think and, yes, do a little bit of high school math. It really isn't that hard to get there. We are being manipulated and lied to. We need to focus on living with this, not be delusional and think we can save the planet, that's preposterous.

BTW, vertical farming is likely the future of mass food production. Do you know what they do in vertical farms to promote plant growth? They bring in canisters of compressed CO2 and release it into the farm environment. It turns out plants eat CO2 and make, well, plant matter out of it (again, high school science). One could very well argue that an increase in atmospheric CO2 might bring with it a boost in global plant-based food production and help end hunger world wide.

You see, these things are not single variable problems or solutions. That's the main thing to focus on. There's always more to the story. Think.