The first thing to understand is that money at this stage is mostly investment: the goal is to develop the technology and try to scale it up, not to just offset the carbon in the short term (in much the same way as investment in solar was not just to generate electricity but to enable economies of scale to actually get it to be a serious contender for replacing fossil fuels).
Why is such technology important to invest in? Two main reasons: firstly it could very well be the most economical means to make certain carbon-emitting processes carbon neutral, for cases where there is not currently a good means to eliminate the carbon emissions. Think aircraft emissions, for example. Secondly, even if we completely eliminate net carbon emissions, global warming will still continue for a fair few decades, as the climate takes a long time to actually reach equilibrium. If we want to avoid that equilibrium being too hot, we will need to remove carbon from the atmosphere. And while planting trees is generally a good thing, it's not really a feasible way to actually remove enough carbon from the atmosphere to make much of a dent (only growing new forests generally removes much carbon: mature forests are mostly carbon neutral, and the carbon capture process is slow). Technology like this, if it can be scaled and use renewable energy, has a chance of being able to make this difference (though the biggest question, apart from whether the technology can actually work, is who will pay for such removal, if it's not for carbon credits).
Not really, as long as we hit net zero fast enough that’s sufficient. People working on carbon capture are really trying to sell the idea of carbon capture but it’s optional.
Earth slowly returns to equilibrium point well below current CO2 levels without our intervention and current levels aren’t so high as to be unlivable. So the only question we need to ask is if it’s easier to cut emissions or sequester them.
We had to hit net zero 10-20 years ago. We’re already hitting climate tipping points, so we’re already committed to some form of climate engineering. The lowest risk approach to that is carbon capture.
> At the start, cutting is much easier. But each percent is harder to cut than the last.
That isn't necessarily true. Solar panels are less than 5% of the price they were in 1990. Economies of scale reduce costs. There is a clear path to fully decarbonizing the power grid without raising energy costs using some combination of renewables and nuclear -- France has already done this. Nearly all of transportation and heating could be electrified.
You don't get into significantly higher costs until you get near the end. Biofuels would function for aviation but would raise the price if no one can come up with anything better. Cement emits CO2 and it's not currently obvious what to do about it. But if you would e.g. institute a carbon tax, it's not implausible that the market would find a more efficient alternative that isn't currently known.
It doesn't make sense to spend resources on capture until it costs less than the alternatives, and it's not implausible that it never will.
I'm not just talking about the grid. Consider airplanes. Figuring out either biofuel or carbon capture that 90% of flights need is a lot more difficult than making a car electric.
The vast majority of CO2 emissions are from burning fossil fuels to generate heat/energy on the ground. We already know cost effective alternative ways to do that. That's ~90% of the way there with no increase in costs.
We don't really have to "figure out" biofuels. They exist and are only moderately more expensive than fossil fuels. Institute a carbon tax and planes would run on biofuels and have 20-50% higher fuel costs, possibly less if cheap renewables lower energy costs in general and thereby the production cost for biofuels. On top of that, if petroleum fuels were only being used for aviation they might have lower economies of scale and higher prices, making biofuels more competitive.
One of last big things we still need to figure out is what to do about cement. But even there half of the CO2 attributed to it is energy use rather than the chemical process, which could be switched away from fossil fuels. Then we could use less concrete and more wood or steel. Or someone might come up with a cost effective alternative to cement in concrete. The incentive to do all of these would exist with a carbon tax.
The market is going to do whatever is most cost effective, even if it's only more cost effective by a modest percentage. But then all you need is a modest percentage in carbon tax and you're done.
> So the only question we need to ask is if it’s easier to cut emissions or sequester them.
I can think of another. How do we get everyone to do the answer to your question?
I think it’s fine to identify what’s most efficient in a political vacuum, so long as we then address how we actually convince people to do it (lower consumption & emissions).
My sibling comment even argues for needing to invest in technologies for removing carbon from the air because we need a way to remove the CO2 that’s already up there.
I believe that putting this same money into building more renewables is better use for the money. We can worry about removing CO2 from the atmosphere once we stop dumping immense quantities of it.
That being said, this problem is as much economical as technical. Microsoft, want to help reduce CO2 levels? Spend this money on lobbing to introduce carbon prices, e.g. see Canada’s carbon tax or the EU carbon tax WITH a border adjustment.
Why is such technology important to invest in? Two main reasons: firstly it could very well be the most economical means to make certain carbon-emitting processes carbon neutral, for cases where there is not currently a good means to eliminate the carbon emissions. Think aircraft emissions, for example. Secondly, even if we completely eliminate net carbon emissions, global warming will still continue for a fair few decades, as the climate takes a long time to actually reach equilibrium. If we want to avoid that equilibrium being too hot, we will need to remove carbon from the atmosphere. And while planting trees is generally a good thing, it's not really a feasible way to actually remove enough carbon from the atmosphere to make much of a dent (only growing new forests generally removes much carbon: mature forests are mostly carbon neutral, and the carbon capture process is slow). Technology like this, if it can be scaled and use renewable energy, has a chance of being able to make this difference (though the biggest question, apart from whether the technology can actually work, is who will pay for such removal, if it's not for carbon credits).