This is madness. A Reddit user has been playing Civilization II for more than a decade and the results are awe-inspiring/depressing:
A couple of in-game millenia later, the landscape is mostly “inundated swamp land,” as the polar ice caps have managed to melt 20 times. Engineers are constantly building roads for armies that get annihilated the next turn by enemies, and feeding the military beast means the warring nations have no time to clear the swamps or nuclear fallout. The lack of sustainable farmland has led to a starving, miserable world population suffering under Communist and Theocratic control. “I was forced to do away with democracy roughly a thousand years ago because it was endangering my empire,” Lycerius writes; his Senate kept overruling him when he wanted to declare war on the Vikings.