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Comment by akmarinov | Hacker News Reader

Virtually unlimited clean energy like that would allow us to vacuum back the carbon dioxide from the atmosphere and reverse the damage we’ve done in the past 200 years, while allowing us to continue with our fossil fuel infrastructure.

It’ll also enable unlimited desalination which would allow more crops and a lot more food, ending a whole mess of problems.

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reverse the damage we’ve done in the past 200 years

From the little I know about it, this damage you talk about only means getting CO2 levels back to normal. Great, but by the time that becomes realistic (seems no sooner than 2050 since that's about when there will be a demo, and only a demo) it's getting a bit too late for all side effects, i.e. global warming and all damage which comes with it. Add to that the whole latency of the system, and I'm not too optimistic.

I'm honestly surprised where these fantasies come from.

In order to get that energy you'll have to build a hugely complex industrial installation. That won't be for free. It won't be easy. If it will even be possible remains to be seen. You'll still need transmission lines and other infrastructure that costs money.

Whether it'll work and if it works whether it will be cost competitive to renewable energy (still improving and getting cheaper) remains to be seen. But it almost certainly won't be "virtually unlimited".

I feel it will be waaaay cheaper than any alternatives though (order of magnitudes, that we are likely forced to be spending on this regardless).

If success was guaranteed money wouldn't really matter.

Though part from success we have deadlines etc. that complicate the matter further. Regardless, this is welcome news.

From misunderstanding exponential growth, which it will jump start. They think people will continue to live as they do now, just with lower electric bills.

Norman Borlaug on receiving the Nobel Prize for the green revolution, said it well:

"The green revolution has won a temporary success in man's war against hunger and deprivation; it has given man a breathing space. If fully implemented, the revolution can provide sufficient food for sustenance during the next three decades. But the frightening power of human reproduction must also be curbed; otherwise the success of the green revolution will be ephemeral only.

Most people still fail to comprehend the magnitude and menace of the "Population Monster"...Since man is potentially a rational being, however, I am confident that within the next two decades he will recognize the self-destructive course he steers along the road of irresponsible population growth..."

We haven't steered away from that course. Fusion would accelerate us on it. If we have to come into balance at some point, why not now instead of when we exhaust fusion's potential? Why does this community think we can solve every technical problem from the moon to Mars to fusion, but we can't live in balance with nature?

Wealthy countries around the world are seeing collapsing fertility rates and exploding carbon & resource use. We can’t live within balance with nature because of the second item, not the first.

Fusion and space colonization can get us to sustainably supporting trillions of human lives in the solar system alone. Fundamentally there is no living in balance with nature; the only barrier that can’t be overcome is the heat death of the universe, and there’s no living in balance with that, either.

>> but we can't live in balance with nature?

With greater prosperity comes reduced birth rates. This has been seen across the globe in a variety of cultures. The thinking goes that if fusion, cheap energy, can lift people out of poverty it will contribute to decreasing population growth.

Except that we actually have steered away from this course, though not through any conscious decision. More economically developed nations tend to have lower birth rates, with the most affluent somewhat below the rate of replacement. In my opinion, the best method to curb population growth is to get more of the world up to that standard - and energy production is evidently a huge factor. See for instance the work of Hans Rosling.

And either way, energy-intensive practices wouldn't accelerate environmental destruction, they would enable us have a smaller footprint in the natural world through, for instance, vertical farming (currently infeasible because electricity is more expensive than sunlight), carbon capture, switching from aquifers to desalinated seawater, etc.

Someone I think on a slashdot post calculated that we'd have to process about half the planet's atmosphere to get back theCO2, that is liquefy that much atmosphere to collect the CO2.

Then we'd have to put I guess hundreds of cubic kilometres of liquid co2 somewhere. I long ago lost any hope we will deal with it.

Taking in mind absorption rate by plants, I wonder if you could do a controlled release in somewhere like a rainforest such that a minimal amount would make it back into the atmosphere and a majority would be taken in by trees and plants. Alternatively build large green houses and vertical farms and pump it directly into there.

Plants are not a sink for CO2, just a transition point. Any CO2 that is taken up by the plant gets released when it dies and decays.

Couldn't you bury the plants, the same as trees, sequestering the carbon underground?

If you have the energy to distill a large proportion of the earth's atmosphere you have enough to crack the O2 from the C and not mess with plants etc.

True, and I had not considered that. I like the idea of growing more trees though.

Trees = good, I'm with you.

You could do that. It is how most fossil fuels got underground in the first place. OTOH if you have the ability and available energy to bury all of that plant matter, maybe you could instead just convert the CO2 directly to carbonate and skip the part with the plants.

You're missing the trick. If you've got "free" energy, you can reverse the process: combine the CO2 with water and turn it back into high density hydrocarbon solids that you can safely bury. Or, if you can pick the hydrocarbon, use them in construction.

Doesn't help with the amount of gas you'd need to process, but the storage part is doable.

Very good point, thanks.

200,000 years later: nuhumans "wooah, I just discovered that there are all these hydrocarbons buried in the ground. These would just be perfect for this industrial revolution we are having"

That would honestly be a huge upside to this approach. We've already extracted most of the easily accessible energy resources, so if our society fails, the next one will have a much harder time moving from agrarian to industrial.

> vacuum back the carbon dioxide from the atmosphere

For what it's worth, it apparently is much easier to scrub CO2 from sea water than from atmosphere.

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