[tohmasu]

I get the feeling there's a "snake eating its own tail" aspect here.

Assuming carbon sequestration can be done at scale, it will likely require energy, maybe even a lot of energy.

So where's this energy going to come from? Well... global energy demand is increasing as-is and the winners are: coal, oil and "natural" gas (which is a fossil fuel): https://www.statista.com/statistics/222066/projected-global-...

Even assuming the forecast 5x increase in "renewables*" (I can't find the double asterisk footnote) until 2050, it seems unreasonable that a ~250EJ "blue team" (hydro, nuclear, other renewables) could plug a ~500EJ hole created by the "red team" (coal, oil, fossil gas).

We need a magnitude more clean power and all the wind, solar and wishful thinking in the world aren't going to cut it.

[mbgerring]

> Even assuming the forecast 5x increase in "renewables*"

I don't know where these figures come from, but the IEA underestimating the deployment of renewable energy, as well as cost reductions, has become a running joke among people who model energy or study the electric grid.

Renewable energy is a growing and profitable field, and if you're concerned about not having enough clean electricity to power carbon removal, there are many opportunities to work full time on expanding renewable energy.

[tohmasu]

>> Even assuming the forecast 5x increase in "renewables*"

> I don't know where these figures come from /../

There is a link to a well respected statistics site right above the line you are quoting, so if you don't know where the figures are coming from, that says a lot.

[mbgerring]

The data don't come from "statista.com", that's just where the graph is hosted. Clicking on the "sources" link, to see where the data actually came from, brings up a paywall.

So, no, it is not clear where these data actually come from, it's not straightforward to find out without paying, and my point, about the IEA being very, very wrong in its projections about renewable energy for more than a decade, still stands.

[tohmasu]

The source is available without paying, you could have had asked. "I don't know where these figures come from" isn't a question, it's the start of a bad faith argument.

As for your claim about the IEA, you're welcome to post some source to back that claim, other readers may be interested.

[lucb1e]

> carbon sequestration [will] likely require energy

Yes, but that doesn't mean we won't need it.

Take air planes. We can't just put batteries in there: too low energy density or something (I'm no physicist, but they won't fly very far is what I gather). But by capturing the CO2 (at exhaust, or atmospherically) that they put out, we can have both airplanes and a stable climate -- assuming it's all done right.

Who wants to have a wind turbine in their back yard? A nuclear power plant? Who lives near that hydro plant in the middle of nowhere? We could instead capture CO2 away from people if power is cheap, before sending the rest down a slightly lossy transmission path.

Driving regular passenger vehicles electrically is definitely less energy intensive than capturing the GHGs that a combustion engine produces, so it would obviously be counter-productive to use capture technology for those sorts of things. But we can use it for other things like chemical processes that produce a GHG as a byproduct where it's hard to capture (new buildings using concrete, for example) or when we don't have the technology to get rid of the emissions.

Right now, the quickest wins are from emission reduction. This capture technology is something we need to have ready for the next phase of keeping our natural habitat stable.

[rcpt]

> Who wants to have a wind turbine in their back yard?

Here in Los Angeles we have honest-to-god oil derricks in our neighborhoods and the NIMBYs don't even notice. Apartments OTOH...

[lucb1e]

I went to a wind turbine some time because I was curious how loud it would be. It doesn't seem that loud actually. Maybe it's more the looks? (Personally, it's not that terrible and, well, we don't have a choice so define some nature reserves and for the rest go ahead.) Either way, I meant it more in the proverbial NIMBY sense rather than that literally everyone feels the same way about them.

[DoingIsLearning]

> Take air planes. We can't just put batteries in there: too low energy density or something

Actually for completion it is a feasible proposal [0] (Obviously not for jet propulsion though).

[0] https://www.airbus.com/innovation/zero-emission/electric-fli...

[Mizza]

One of the more exciting things in green aviation is "air to fuels". There are companies working on converting atmospheric carbon into hydrocarbons for storage (using renewable energy). Those hydrocarbons can then be used as jet fuel, so it's isn't carbon-negative, but at least it's carbon-neutral. Any hydrocarbons left over that are stored are carbon-negative.

[lucb1e]

Ack, I know of those. Isn't that the same thing as carbon capture? It also uses more energy to capture the carbon than the fuel will produce after burning. Just that the output is usable fuel (yay put it back in the atmosphere ^^' but better burning circular than burning fossil fuels) rather than rocks like Climeworks and Olivine output.

I never actually saw anyone compare the options. Anyone know if it's cheaper (or less energy-intensive) per ton of CO2 to turn atmospheric CO2 into rock and continue using fossil fuels for another century until oil really starts playing hard to get, or if it's cheaper (or less energy-intensive) to use this air-to-fuel technology?

[brightball]

Honestly, if carbon capture is effective for the power requirements that it has...build a nuclear facility dedicated to the carbon capture tech.

[kisamoto]

Solar can be used to a certain extent.

And geo-thermal - that is currently being used in Iceland by Carbfix + Climeworks.

Also worth noting that a lot of these technologies do thorough lifecycle analysis to make sure that despite the energy usage required they are still carbon negative.

[dd36]

Nuclear.

[londons_explore]

If you know ahead of time that you need a massive amount of power, and you have no location constraints, then first you'd buy up all the 'free' power from hydro stations that don't have enough transmission capacity.

Next you'd probably build geothermal power stations at a huge scale in iceland or a similarly volcanic places. That power is still cheaper than solar or natural gas by a decent margin.

Nuclear is a contender only if you can find a place willing to let you skip all the red tape and build rather unsafe 1970's designs...

[FL33TW00D]

All of these systems are going to require radical construction of hundreds and hundreds of nuclear reactors.

This has economics of scale benefits, and I expect reactors such as the ones discussed in this video: https://youtu.be/7gtog_gOaGQ to be produced on a factory line extremely quickly.