There are many difficult achievements in "Frost Age 2", and unstoppable progress is one of them. To do this achievement, the material requirement needs to reach 1000, and then it can still maintain a "dirty-free" hygienic state. That is, have at least 1000 material requirements and no slums.
How to make the unstoppable progress achievement in Ice Age 2
Unstoppable progress
The requirement for the achievement is to maintain a "clean" state despite having a material requirement of 1000, or to have at least 1000 material requirements and no slums.
What you want to do is build a material colony to supply most of your needs, and build filter towers to handle excess slums from other sources. Avoid putting technocrats in power as they will reduce material requirements.