ldr; Adding pollution for progression == bad, adding pollution on enhance realism and immersion into the GT theme == great
While pollution is a good subject to address, "pollution" simply doesn't effect all machines the same way. Using "pollution" to force tier advancement is equally contentious (my first thought is, "ya, no") Using it to broadly impact machine performance is simply not reasonable.
Simply a single "pollution" wont address the subject correctly. Air pollution should lead to smog -> acid rain -> water pollution -> ground pollution. "Pollution" Broadly should would mostly impact biological entities. Pollution should not be singularly to encourage tier progression. In fact properly laid out, it can encourage both progression, machine selection, and ecological awareness. Progression of energy generation may be driven by reducing air pollution, while higher tier production machines should make more of it. Lending to ecological thoughtful building, including cleaning the pollution up properly before it makes it into the ecosystem
Pollution creation:
* Air pollution for the most part should only be created by machines that burn (high emission) and melt (medium - low) emission
* Water pollution would be further produced by machines that consume water. washers (high emission), chemical reactors (high emission), furnace boilers (low)
* Ground pollution could be generated by storage or presence of hazardous materials, this also lends to contaminated biomes
Impact to machinery:
* Air pollution would impact machines that require clean air to operate: solar machines (high), burning generators (low-med), chip fabricators (high), melting (low)
* Water pollution would impact machines that expect clean water to operate: washers (med-high), steam (from not distilled water) (very high)
* Ground pollution would mostly not impact machines as it leads to air / water pollution levels
* Machines that don't have these requirements should be un-impacted by respective pollution
Impact to bio(me):
* Air pollution at lower levels (smog) should lead to quicker exhaustion and slow plant growth. At higher levels it should lead to acid rain that should damage any entity out side
* Water pollution at lower levels should reduce air capacity under water, and slow plant growth. At higher levels young animals should not grow up, it should increase the chance of having acid rain, submerging in water should cause damage, including rapid loss of breath under water.
* Ground pollution at low levels should impact movement speed. At high levels animals cant breed, ground should be visibly tainted, dangerous and require manual cleanup, mobs should spawn during the day. later mutated and / or aggressive passive mobs should occur including angry cows that attack player and other passives (killing off the heard).
Generally the more toxic the environment the more hostile and visibly disgusting it should become.
Pollution progression
starting with air pollution by burning things we should start to see smog generate in the environment and slight impact to water pollution levels and even lesser impact to ground pollution. As the player starts using machines that have higher impact to water pollution (or heavy air-pollution over time) we start to see impact into the water system, sustained pollution here creates high impact to ground contamination and the relationship between air and water pollution should be maintained (A high water pollution will result in air pollution). A similar relationship would exist between ground pollution and water pollution, and by extension air pollution. For example an air index of 100 might result in water pollution of 10 and ground of 1 (random numbers to show some relation) (after some time of it saying at 100) if we have a ground pollution of 10, eventually water and air would become 100 and 1000 if not abated by controlling measures.
Distribution, containment
Distribution similar to your prior note makes sense. The source of pollution should spread at some rate at some logarithmic rate. (similar to the reactor heat exchanger) Chunks not creating pollution should absorb some of it naturally (not very much) however would still be impacted by progression noted above. Pollution should be containable with the right tools, IRL we can minimize the production of air, water and ground contamination and there for the same should apply. For instance we can limit the amount of emissions by adding catalytic converters to ensure that pollution particulates are converted to more inter substances before emission.
Pushing tech tier
So now putting this all together in the stone age we should only see pushing in the air contamination and little in the way of impact. Starting in the bronze age we should see increased impact into the air system and some into the water system. Steel by carbon burning should see massive air pollution. Starting in the electric age we should start to see massive water pollution, mostly from ore washing and chemical reaction. and So on. Higher tier machines of the same variety should actually produce more pollution. So how do we encourage moving forward? Abatement and containment tools should only become available with products from higher tier machines. Things like simple carbon filters may help marginally with water pollution but something like a catalytic converter requires expensive and rare materials that we can only produce in quantity from pollution crating processing. So if you want to live in that wasteland you created from only using a tree farm and charcoal, you can, but it's going to be hard.
Have done this serveral times!
