Originally posted by kinglizard
Originally posted by ArchAngel
Yes, good point, but you would first need an atmosphere to allow the plants to live. After that algae and mosses would be a good place to
start, until the planet was able to support larger plant life.
Mars already has a CO2 atmosphere. The only thing you really need to add is water.
The Martian atmosphere results in only a weak greenhouse effect that raises the surface temperature by about 5°C. Consequently, most of Mars is well
below the freezing point of water for most of the year. Moreover, even when the daytime temperature at low latitudes does climb significantly above
freezing, the atmospheric pressure is so low that water ice turns directly into water vapor without first becoming liquid. So you see, we need to
create an atmosphere on mars before life is even remotely possible.
There are bacteriae that can produce methane and oxygen with water and carbon dioxide, others produce ammonia and oxygen with water and nitrogen.
Both are greenhouse gases, that are far weaker than FCKWs, but far stronger than carbon dioxide.
Let's assume 1% of the surface is covered with such bacteriae and that those use sunlight with an efficiency of 0,1% to produce their greenhouse gas.
This would cause one billion tonnes of ammonia and methane to escape into the atmosphere. That is enough to heat up the planet by 10 K in 30 years.
These gases would protect the surface from UV radiation, but would also be destroyed, which doesn't matter, because they'd constantly be replaced by
the bacteria.
Through the heating caused by these gases, more carbon dioxide would be released into the atmosphere, which wouldn't only heat up the planet through
greenhousing, but also make a much thicker ozone layer (carbon dioxide raises the formation of ozone), which would slow down the destruction of
ammonia and methane, which would cause a higher concentration of these gases.
Further heating through organisms can be acieved by letting black organisms grow on the surface of the planet. This would lower the albedo and
therefore heat up the planet.
Best would be to engineer organisms (e.g. lynchens) that are able to grow on the polar caps. This wouldn't only heat up the planet directly through
albedo change but also through carbon dioxide release.
The major problem with this project is that no plants are known that would live in such cold regions, although there are lynchens that survive
temperatures of -100'C and are still photosynthetically active (and therefore grow) at -24'C.
But if such organisms could be engineered, the result would be very helpul.
SOURCE