And they can't be faulted for that decision. What they can be faulted for is the next step in the process; creating the flawed causes and effects for what they would put under the umbrella of global warming.
You're stating something false. They absolutely can and should be faulted for putting this trash in the game despite whatever twisted logic lead to its inclusion. In fact, their decision to include it indicates a fundamental flaw in their design mentality in the phase it was made.
The extent of human impact on GW remains unknown, but we do know it sure as hell isn't as drastic as in civ. But this goes beyond poor implementation. Let's illustrate:
1. No meteors hit the planet and cause massive dust issues, killing large #'s
2. The tsunami event was pulled
3. Hurricanes don't kill off over 1/2 of the population in a city at given periods of history
4. Massive earthquakes don't drop population, either.
5. Your government is not forcibly changed w/o outside influence due to ignorance in your population (or intelligence, depending on how you're playing).
See the pattern? Each of the above was not included for a reason, and yet in each case they'd be equal or BETTER than GW in civ IV. Why were these features not selected for inclusion in the default game? Well, they're based on random chance and have devastating effects that are outside the player's control. Forcing GW into the game AND using a bad mechanic to do it when so many other things could have been included in similar crappy was is one of the MAJOR reasons people interpret its inclusion as political ----> because that fact tells us it *was* political to someone making the game, at least to an extent. I don't buy for a second that this was placed in the game w/o knowing it was a poor mechanic with limited control.
So basically the logic of "they decided to put GW into the game and then assigned it a mechanic" is making an excuse for bull
. Why put anything into the game, or avoid putting in all the other possible garbage? If they can't come up with a good mechanic to implement something, that is a very, very good reason not to implement it. Especially when the mechanic is based on something that doesn't have clear causality.