Carbon dioxide collector

(speculativity warning)

There's plenty of building material in the atmosphere. SVG

Good ones and bad ones

Good ones are not self replicating maybe drop the extracted carbon down in form of graphite chips stop carbon extraction at a certain level and care about their fate after their end of service. They have a rather big size that makes handling them easier and may also watch out for bad ones. Bad ones use the extracted carbon solely for self replication and at some point start to produce nasty gasses like Cyanide (HCN) or nitrous gasses (NOx) suddenly and in huge amounts

Both of them may endanger planes and create shadows hampering plant growth.

Locating solar cells for CO₂ recuperation sparsely distributed in the air or on the sea instead of placing them concentrated in one place on the ground may be good for environmental (no paveover) and political reasons.

Water

Atmospheric CO2 collecting boya. SVG

Swimming units have the benefit of easier access to wind power and easier propulsion. There should be no problem to keep them stationary.

Air

Micro airships:

• have a very lightweight bubble as main body in a size range between 10um and 100.000um
• use hydrogen as lifting gas
• use their surface for harvesting of solar energy
• are capable of water capture and splitting for compensation of hydrogen diffusion loss
• may be capable of carbon dioxide capture ond splitting
• may be capable of self replication
• may (if malicious) create some nasty gasses

Questions

To investigate: If replicative how fast could they replicate (doubling time) depending on their diameter?
What is the limiting factor: solar-power for hydrogen generation, diluteness of CO₂ or something else?

To investigate: Can they be made to actively propel themselves? Their high volume to mass ratio makes this rather difficult when there's even the slightest bit of wind. Flattening the bubbles drops the aerodynamic resistance significantly.

To investigate: AP manufactured solar cells & mechanosynthetic carbon dioxide splitting

Alternate forms

For swimming ones - micro ships - essentially the same reasoning applies. They need only plain air as lifting medium must be sturdier can use the wind for propulsion and are easier to collect manually (skimming) if something goes wrong.

Extraterrestrial application

(SciFi warning!)

The upper layers of the Venusian atmosphere would be the perfect place for replicative micro airships. There they would provide us with the opportunity of doing an terra-forming or rather terra-changing experiment. If the extracted carbon can be sealed good enough against the frequent and powerful strokes of lightning (questionable) and the extracted carbon can be hold at high altitudes until the lower atmosphere have cooled enough so that the carbon could be put to the ground without reigniting (questionable) then you end up with a cool superdense (too dense for humans) oxygen atmosphere (and a very dangerous situation). Now its the question whether the excess oxygen can be bound into the soil or ridiculous amounts of hydrogen or other abundant reducing elements have to be carried over.

What would a Venus with its over 100 day long day and higher solar constant look like if all the carbon where bound and most of the oxygen where trapped into the soil or water? Would there be lots of poisonous heavy metals around? Would there be any dry land left? How high would the waves get with the extreme winds at the day night borders? What about water vapor clouds, lack of magnetosphere ...? For analysation of those and related questions go to the terraforming Venus page.

Related: Gas giant atmospheres