Perhaps the health effects of a Jungle could be removed with a Hospital...and once you research Medicine, Pharmaceutical resources could have a chance of appearing in jungle, similar to new resources appearing in a mine. This would also improve the benifit of going with Environmentalism if you left some jungles up.
There could also be exotic wood luxury resources that has a chance to appear, which could be accessed with a lumbermill.
There aught to be some way you could dynamically link Jungles and Environmentalism, that might end up being better than the flat +6 health and +1 happiness per tile. With that civic enabled, you could replant jungles and forests using the tree-farm approach, and the appearance of pharmaceuticals and exotic woods would give you the health and happiness bonuses. Perhaps accessing these resources would require you to be under that civic, you could then trade surplus supplies to other leaders.
This way, you could replant forests to provide production, and replant jungles to provide health and happiness, which over time would provide the benifits that could be removed from researching multiple Future Techs, providing more dynamic gameplay.
hmm...
- After researching Assembly Line (or some other late-industrial tech), exotic wood luxury resources could begin appearing in jungle tiles.
- After researching Medicine, pharmaceutical resources could begin appearing in jungle tiles.
- Hospitals could remove the negative health effects of jungles nearby.
- Running the Environmentalism civic is required to access these resources. Exotic woods are connected by a lumbermill, medicines by a camp.
- While the civic is required for access, surplus resources can be traded to any leader like hit movies or wonders. If the civic is changed, the resource access is lost, like losing the Broadway or Hollywood wonders.
- While under Environmentalism, forests can be replanted for improving production, and jungles for the health or happiness resources.
- Exotic woods add a hammer bonus to the tile, medicines add a food bonus to the tile.