[NOTE: POST MAY INCLUDE SPOILERS]
There's a plethora of market features that can be found on planets, most of which add to the hazard rating of the planet, and it occurred to me the other day that some of these planetary features seem like they should be non-permanent and removable or otherwise overcome by the player within the time-frame that a game of StarSector takes. I think having certain planetary features be overcome would differentiate the market features a little over just being several flavors of 25% or 50% hazard rating modifiers and would add an interesting dimension as well: For instance, Certain planets with good deposits but certain "removable" features would have a high hazard rating at first and could be a poor candidate for early colonization but, upon finding certain techs or just getting enough capital, could be dealt with by some time and monetary investment and make the planet a worthwhile and productive colony in the late game.
I think a few specific examples would showcase my suggestion better:
HOT/EXTREME HEAT/COLD/EXTREME COLD
Solved or partially solved by constructing a Planetary Shield Generator on the planet, which would create a new modifier on the planet. If the condition is hot, the description of the new "Planetary Shield Climate Control" modifier would be something like "The shield generator on this planet is reflecting excess energy from the planet's star, artificially lowering its blazing temperatures to a more tolerable level." For cold conditions, the modifier would read "The shield generator on this planet is configured to act as a replacement or supplement of the market's atmosphere, letting in whatever limited energy its star provides and trapping it with the shield as long as possible to warm the planet to more tolerable levels."
In either case, having the Planetary Shield Generator operational would decrease the hazard rating by the "Climate Control" market condition by a low amount (Say ~1%) each month, up to a maximum of -25% (completely nullifying the penalty of a regular cold/hot world, and partially dealing with extreme cold/hot worlds.). If the planet's shield generator is disrupted by, say, a raid, the hazard rating increases by a similar rate per month until the disruption is over.
IRRADIATED
This condition may also be solvable via a planetary shield, based upon the description of Irradiated including that the colonists live in shielded habitats. Building a planetary shield on an Irradiated world would add a different shield-based market condition with a description like "The entire planet is being shielded from radiation by its shield generator. However, it will still take some time for the lingering effects of the radiation to dissipate." Having the generator decreases the hazard rating by a low amount each month, up to a maximum of -25%. However, if the planet's shield generator is disrupted, the hazard rating resets completely as the planet immediately gets bombarded by the full force of the star's outgoing radiation again.
DECIVILIZED SUBPOPULATION
This one should be able to be eliminated pretty much immediately with no help from advanced technology, and I can think of at least 2 ways to implement it.
The first is actively, by enacting or adding some sort of policy tab that allows you to deal with the unruly subpopulation. There could be two separate ways to do it by policy: Either by integrating them relatively peacefully (less stability malus and keeping pop growth bonus, but takes longer to eliminate the malus), or by forcefully cracking down on the populace making your life difficult (higher stability malus and less pop growth, but the malus gets nullified much quicker). This could either be just a product of time or require some credit intake like "encourage pop growth" does.
The second is just passively reducing and later eliminating penalties just as the market size grows. At market size 9 or 10 where I have billions of people on a planet, the original 1,000 or whatever inhabitants from the subpopulation would be just a drop in the bucket as far as demographics are concerned. Perhaps sufficiently large colonies should then just naturally lose that malus?
POLLUTION
Also doesn't require any fancy technology, just some substantial credit and time investment to enact a planetary cleaning campaign, which reduces the hazard penalty at a low monthly rate until the planet is "clean" and the hazard penalty is completely nullified.
It could be interesting if this modifier could actually be generated on developed planets in some way. Say, you could enact a policy to overlook or reduce industrial regulations on a planet with heavy industry to reduce its upkeep by some extent, at the cost of having a chance to produce the "Polluted" modifier if that industry gets bombed.
METEOR IMPACTS
This is probably the most intuitive condition that a Planetary Shield Generator would solve: Building one on a "Meteor Impacts" planet would create a new planetary condition with the description "This planet's shield generator is protecting it from meteor impacts" and have an immediate -50% hazard rating modifier, nullifying the effect from the market condition Meteor Impacts. This would be temporarily removed if the Planetary Shield Generator is disrupted.