Terraforming Venus; Venus-forming Earth

Terraforming Venus would require taking almost all of the CO2 out of its atmosphere, so it becomes breathable, doesn't crush us (currently 90 atm pressure) and cools the planet down. Using our current mechanical carbon scrubber technology may seem simplistic and unimaginative, but the other options that have been discussed feature similar science-fiction-level ideas (crashing outer solar system ice moons into it, locking carbon into the crust down to a kilometer deep, or getting theoretically present hydrogen out of the mantle.)

This is less likely to happen than being able to move moons around the Solar System. Image from reddit.com/r/mapporn.

Let's make many optimistic assumptions:

That we can build self-replicating independent carbon sequestration plants; this minimizes transport costs and covers the planet.

That they can build and fuel themselves from materials available on the surface of Venus.

That they can withstand conditions on Venus (when the longest any machine we've put down has lasted is on the order of an hour.)

Current carbon sequestration plants are the size of a cargo container, and sequester 900 tons of carbon per year. Assume that this is the rate at which they operate on Venus, and that self-replicating carbon sequesterers are 100x bigger than the real, non-self-replicating ones we have.

Assuming near 100% working replicas, and a one-year self-replication cycle, it would take 40 years to cover the entire surface of Venus with these - after which they would take 2000 years to clean the atmosphere of CO2. (This would still leave a nitrogen atmosphere several times higher pressure than Earth's.)


Venus is not the best candidate for terraforming or habitation, and humans will not settle its surface for thousands of years at least. We should concentrate on terraforming planets in our solar system, building self-replicating technologies, and having humans in isolation from Earth in case of some sort of collapse (most easily, on the Moon.)


On the other hand, here on Earth, just to keep even with carbon emissions at the 2017 level, we would need 40 million of the scrubbers we currently have. That means no matter where you went on Earth, there would be one within less than two and a half miles of you.

We do have machines that are Venus-forming Earth, by making more CO2. They aren't self-replicating, but they seem to have a relationship with one species (unclear if parasitic or symbiotic) and in places they cover the surface just the same.