According to
this story, the best way to begin terraforming Mars is by:
Injecting synthetic "super" greenhouse gases into the Martian atmosphere [which] could raise the planet's temperature enough to melt its polar ice caps and create conditions suitable for sustaining biological life. In fact, a team of researchers suggests that introducing global warming on the Red Planet may be the best approach for warming the planet's frozen landscape and turning it into a habitable world in the future.
More below the fold.
So, which are these "super" greenhouse gasses:
Their study focused on fluorine-based gases, composed of elements readily available on the Martian surface, that are known to be effective at absorbing thermal infrared energy. They found that a compound known as octafluoropropane, whose chemical formula is C3F8, produced the greatest warming, while its combination with several similar gases enhanced the warming even further.
Interestingly, C3F8 is still in use here on Earth. It has an atmospheric lifetime of 2600 years, according to the Intergovernmental Panel on Climate Change (1995).
The researchers anticipate that adding approximately 300 parts per million of the gas mixture in the current Martian atmosphere, which is the equivalent of nearly two parts per million in an Earth-like atmosphere, would spark a runaway greenhouse effect, creating an instability in the polar ice sheets that would slowly evaporate the frozen carbon dioxide on the planet's surface. They add that the release of increasing amounts of carbon dioxide would lead to further melting and global temperature increases that could then enhance atmospheric pressure and eventually restore a thicker atmosphere to the planet.
Two parts per
million does not sound like a lot but most such chemicals in the Earth's atmosphere have concentrations in the parts per
trillion, though every little bit helps as we continue our relentless drive to venusform the Earth.
The story goes on to suggest that astronauts on a future Mars mission could create them since
the raw materials for the fluorine gases already exist on Mars, [snip] It would otherwise be impossible to deliver gigaton-sized quantities of the gas to Mars.
To me it would make more sense to send automated factories to start making this stuff before we sent astronauts. After all, we're going to want to send robotic factories beforehand to prepare the landing site and manufacture fuel, air and water. Why not add a C3F8 generator?
Given the rate at which we are changing the climate of our own planet, we should probably get right on this. The "super" greenhouse gasses are really long lived. We may have stopped using most of them but for some species concentrations are still going up.