Environment Level runs from 1 to 10 per area and it gates pretty much everything. Story progression, shop unlocks, new Pokemon, the Pokemon Center. The fastest way to raise it? Build habitats and crank up your Pokemon's Comfort levels.
Steps#
- Focus on raising the Comfort (Comfy) Level of Pokemon living in the area — this is the biggest contributor.
- Complete Requests from Pokemon in the area for additional Environment Level progress.
- Build structures and place building kits to increase the area's development score.
- Having Legendary or Mythical Pokemon in the area accelerates progression.
- Build houses and move Pokemon in — this raises Comfort faster than open-air habitats.
- Play mini-games with Pokemon to boost their Comfort Level.
Habitats That Raise Environment Level
Every habitat you build raises the environment level of its area. Here are three at different complexity tiers.
x4
Tall grass
Grow 
Burn 
Fly 
Water 
x4
Tall grass
x1
Large Tree (any)
Litter 
Chop 
Build 
Gather 
Four things: building habitats, placing decorations, planting trees, and cleaning up debris. Habitats give the most points per action. The environment level is tracked per area, so focus your building in one area first to unlock its rewards faster.
Higher environment levels unlock new areas, better NPCs, and rare Pokemon spawns. Level 3 in an area lets you build a Pokemon Center there. The exact thresholds vary by area, but expect to need level 3-5 for most major unlocks.
No. Each area has its own environment level. Withered Wasteland, Bleak Beach, Rocky Ridges, and Sparkling Skylands all track separately. You'll need to build up each area independently.