Ocean levels can rise, turning land tiles into water tiles, and destroying terrain placements(roads, mines, solar cells, etc.), any land units there, and even entire bases. Bases can be protected if they have a pressure dome built, this preventing submerging, and turning them into a sea base.
- Each borehole built warms the planet up. The more heat you produce, the faster it'll keep happening, and the more it will raise.
- Once the necessary technology has been researched, a council option can be submitted to melt the ice capes, thus causing flooding.
- Once the necessary technology has been researched, there is an option to propose to launch a solar shade. There is also one after that to launch an additional shade. This will cool off the planet to some extent, but won't stop the flooding if you have enough bore holes.
- To prevent submerging, terraformers can be used to raise the level of land. They can do this anywhere except where a base is at. Rising all the land around it may help a small bit, but the only way to save it is to build a pressure dome. Note, even bore holes can be risen to higher terrain, along with river tiles, and anything else.
Deliberately flooding the planet is a good way to destroy your enemy's bases, they not always having time to build enough pressure domes, and not able to afford to rush production for all of their bases. This also destroys their terrain enhancements, and eliminates land they formerly used to move their ground troops about.
The AI doesn't handle the flooding very well, having trouble adapting to proper fighting styles. Of course the AI also has trouble with the concept of building supply crawlers, and many other things, that make it rather simple to beat even at the highest level once you have mastered the basics of this game.