Planetary engineering


Planetary engineering is the application of technology for the purpose of influencing the global environments of a planet. Its objectives usually involve increasing the habitability of other worlds or mitigating decreases in habitability to Earth.
Perhaps the best-known type of planetary engineering is terraforming, by which a planet's surface conditions are altered to be more like those of Earth. Planetary engineering is largely the realm of science fiction at present, although recent climate change on Earth shows that human technology can cause change on a global scale.

Terraforming

Terraforming is the hypothetical process of deliberately modifying the atmosphere, temperature, or environment of a planet, moon, or other body to be similar to those of Earth in order to make it habitable by humans.

Seeding

Seeding is a term used for the process of introducing microbial or algae species on a planet or moon already offering habitable regions.

Geoengineering

Geoengineering is the application of planetary engineering techniques to Earth. Recent geoengineering proposals have principally been methods to tackle human-induced climate change by either removing carbon dioxide from the atmosphere or by managing solar radiation in order to negate the net warming effect of climate change. Future geoengineering projects may preserve the habitability of Earth through the sun's life cycle by moving the Earth to keep it constantly within the habitable zone.

Habitability maintenance

Planetary engineering can also be applied to keep habitability of Earth in the far future. The rate of weathering of silicate minerals will increase as rising temperatures speed up chemical processes. This in turn will decrease the level of carbon dioxide in the atmosphere, as these weathering processes convert carbon dioxide gas into solid carbonates. Within the next 600 million years from the present, the concentration of CO2 will fall below the critical threshold needed to sustain C3 photosynthesis: about 50 parts per million. At this point, trees and forests in their current forms will no longer be able to survive. Unlike other animal species, humankind has the potential ability to prolong the habitability of the planet Earth by extracting and re-injecting inert carbon trapped underground back into the biosphere.