[silentsanctuary]

> It seems we will do anything to avoid the obvious - we need to reduce energy use and transition to green generation.

The idea behind carbon capture projects is this: for years, we have been given warnings that "if we cut all emissions now, we will still be okay", to "if we cut all emissions now, it won't be too bad", and now we're at the stage where even if we meet our emission targets, things are still going to be bad.

If we want to avert disaster, we now need not only to cut emissions, but ALSO to actively remove carbon from the atmosphere. So, these projects are here to try and fill that unfortunate new need, because just cutting emissions will no longer... cut it.

[meandmycode]

Sure, but where does the energy come from to actively remove? Because that's usually the point, the energy creation created more than the removal removed.

[silentsanctuary]

It'll depend on the specific project in question (there are quite a few methods under investigation), but for enhanced weathering (the type under discussion), I found some articles in a quick search that suggest the energy cost of grinding and transporting the rocks is significantly smaller than the carbon removed by the programme, e.g. https://www.researchgate.net/publication/322664372_Potential...

[ipqk]

Arbitrage it from places where green energy is cheap or free. For example, iceland has pretty much 100% renewable energy sources. Already it has an extensive aluminum industry because energy there is cheap, and aluminum is energy-intensive to use it.

So, in theory, if you use green energy to produce a carbon-offset product, it's still a useful product.

[chinchilla2020]

The aluminum smelter in iceland is a former ALCOA smelter from Rockdale TX. They ship the ore in from outside.

Let's not pretend mining bauxite ore is 100% renewable.

[vasco]

Maybe, you now have to produce that aluminum somewhere else.

[hinkley]

Surplus energy from wind farms over land with the right kind of rock.

Anything you can’t shove into the grid grinds rock.

[oldbbsnickname]

It's about scalability of any particular process minimizing net $/t (which includes kWh/t).

[melagonster]

energy is not important. reducing carbon in atmosphere is more important then energy consumption. a lot of energy just escape to space every day.

[LeonB]

In theory, you might be right. But in practice the biggest investors (and boosters) in carbon capture are oil and gas companies — and for them it’s a way to continue business as usual (i.e., continue to increase carbon output) while hand waving about some future CC project that will make this all ok.

[oldbbsnickname]

In general, to be scalable and cheap, CCS needs to be mostly passive activities relying on biology and large surface areas. This would then usually involve farmlands, forests, or oceans. (Not necessarily trees because they lack automatic sequestration.)