A “negative emissions” plant has opened in Iceland

Of course. The article doesn't mean nor need to imply that this technology is practical yet, simply to illustrate progress is being made (and it is).

For any technology you can poo-poo the early stages ("This Wright brothers plane can only fly 200 feet," "This computer is the size of a room and costs several years' salary").

The more CO2 is in atmosphere, the sweeter and less mineral-rich plants become, becoming less beneficial to poisonous to surrounding animals and insects.

The trick is to cut them down at the optimal point (some time before they stop growing) and replant. Then use the wood in a way which won't release the carbon back into the atmosphere: don't burn it or let it rot.

Cutting down trees and building permanent structures with the wood is a great way to take CO₂ out of the air.

That was achieved by placing the scrubber directly on the coal plant's exhaust stack.

> Is the byproduct (not sure if it's purified gas or a solid compound) of any industrial or material use?

No. The byproduct is injected back into the ground to be remineralized, hopefully locked up to prevent its re-release into the atmosphere.

EDIT: If you used the byproduct in another process where it eventually would make its way back into the atmosphere, the process would no longer be carbon negative.

"This month, Climeworks installed a unit that captures carbon dioxide directly from the air and transfers it to CarbFix to inject underground. Because CarbFix has been monitoring the injection sites for the last three years, they can be sure there will be no leakage. And once mineralized, the CO2 will remain trapped for thousands or millions of years. This makes the Climeworks-CarbFix system the world’s first verified “negative emissions” plant."

...at the current efficiency levels. Note that this is only their second installation, so don't expect any miracles. The technology will improve, I'm sure.

Wow really? That seems like a small number. Given that aroun 70+ million cars were sold in 2016, we probably have the industrial capacity to offset the yearly emissions.

I wonder how cheap these will get and if they can be deployed en masse easily

They also mention that it is considerably more efficient to capture carbon at the source. The CO2 concentration is about 200 times higher at the plant (10% vs 0.04%). They state that it costs about 1/10 as much to capture at the source.

So extrapolating from that, then the the plant they built in Switzerland, which 900 tonnes/yr directly from the air, could potentially capture 9000 tonnes/yr and would handily manage a coal power plant.

http://www.sciencemag.org/news/2017/06/switzerland-giant-new...

It's not that we can't "terraform" our own planet. It's that the consequences of getting it wrong, in doing so deliberately, could easily be worse than those of the "accidental" ways we've been doing it for a couple centuries now...

> theoretically terraform some other planet

That's the problem, it's all just theory and even for Mars we don't think it would be easy. For planets like Venus, straight impossible at our current level of tech and the constraints of such worlds.

Yes, we can 'terraform' earth. The problem is cost.

The problem is that "terraforming another planet" is stuff that young men who are impressionable read in science fiction, it isn't reality. We can't terraform another planet. We haven't even successfully run a fully-enclosed self-sustaining ecosystem capable of supporting human life on earth. We have never sent anyone to another planet, and the rocket equation highly constrains interplanetary transportation, let along radiation shielded interplanetary transportation capable of sending humans.

We will _never_ terraform Mars, I doubt a human will ever set foot there. I doubt we'll even survive as an advanced species for 200 more years.

We actually _have_ every bit of necessary technology to sustainably run something very close to modern society, and we are too stupid collectively do fix terrestrial political problems. We don't even need to terraform our own planet, we just have to stop digging up coal and pumping up oil and burning it. No wasteful and inefficient "negative emission" stupidness is necessary. This is like "clean coal". It's something that very, very wealthy people that make money from oil and coal bring up to essentially troll the populace, and distract them from the problem until we're as close to the brink as possible.

I'm sorry to be depressing, but this magical thinking about sending people to Mars and terraforming planets is counterproductive.

edit: I take it back, we can terraform a planet. The sum total of human activity for 150 years has warmed the Earth few degrees (though they are a critical few degrees)

What's wrong with industry becoming complacent once their emissions are neutralized? The goal is to keep the planet intact, not punish emitters.

It seems to me that stopping emissions will be a lot easier and cheaper than capturing them, but if it turns out that capture gets the job done, then that's great too.