Currently, both achievements are triggered together.

You should pay attention to the location of your city.

You'll need to ensure your food output is leaving your city at a very small starvation status which in turn ensures you never produce regular population. How to manage this:

• settle your capital on tiles without food yields
  
• avoid food-producing improvements,
  
• do not appoint Notables that add food bonuses
  
• do not keep a high number of Citizens (instead focus on Artisans and Scribes) to avoid generating too much food
  
• pay attention to monsoon season when yields change so you might get a lot of food
  
• do not forget to avoid the Balanced or Agrarian automated placement of your population while your food output is positive

Use the Tahuk Festival repeatedly to eliminate any regular Tahuk population. Generate Called Population with Stars’ Light (once per Observatory) and Eternal Sunshine (as many times as possible). You may have as many Observatories as you want outside of your territory...

And since we want to trigger both achievements together:

• the capital must be built in territory with a Ridge

Build an Observatory that will later enable the glass conversion. I triggered the glass conversion late in the game (after the last monsoon), and it did not create a rift. This happened more than once while I was trying to unlock the achievement, so it could be by design.

I found it easier to manage playing with only one city (and one territory). I also avoided water tiles as you can see from the image (no river & no lake).

At the moment, the two achievements unlock only together, but this may be a bug. In future updates, they might be triggered independently.
Note: this guide may not be updated in the future if changes are introduced in later updates, but you should be able to follow the same logic to trigger the achievements even in such a case.

Despite the fact that this is still reported as completed by 0% of the users...

...I can confirm that I did unlock both achievements together: