[Taqwus]

The higher-level CCFs (II and III) increase by 2 and 3% a turn, respectively. Nature shrines (religious only) have a similar progression for the entire system.

You'll really appreciate climate improvers if somebody's chucking climate-damaging intel ops at you (they can take a planet down to Harsh or Deadly pretty fast, which will slash population growth -- unless you're Organic and have a Replicant Center, and don't really care about the exact percentages since you get the flat rate as a bonus).