We have a problem about the pollution here.
In Civ3 the pollution in the tiles was representing normal pollution and radioactive pollution. Now in Civ4 normal pollution go direct to the city with a reduction of production. I think that they will do the same with nuclear meltdowns (caused by nuclear plants) but with a higher effect on production than normal pollution.
But and if the ICBM are thrown against a tile that dont have a city? I will recall of a tatic that I used in Pentagenesis.
In Pentagenesis, cities have a laser defense that destroy the nukes. Then I was throwing nukes in the tiles surrounding the cities, thus killing some population inside the city (not half population) and the pollution affected their production. In Civ4 this will not be possible, as we will not have pollution, and the ICBMs will not have any effect in the enviroment. The birds, the chocobbos, the rabbits will still be there. We can have a crate, like artillery do, but the radiation is gone.
My suggestion is to mod it, putting a new terrain, with a green color to represent radioactivity, and damaging units that pass through it. More realistic than in Civ3, where radiation was treated like normal pollution.
Also, a system for testing nukes can be created, to thrown bombs in the sea or in telletubbies island, as the telletubbies will be lagging the game in later turns. The tests can have a effect in politics, with less powered nations in the borders being more benevolent, and equal powered nations making pressure to stop the tests, or a effect in technology research for better nukes.
More types of nukes will be better too. We can have some fusion technology to allow more destructive effect in the enviroment (like dozens of tiles with radiation). A unit called radioactive worker, with proper clothes, can erase it. The radiation will disappear naturally after some turns, but this type of worker can turn this more fast. We have new possibilities here, if is true that we can mod everything in this game.