I like the concept of exaggerating the impacts of an individual's actions. Today, you can drive as much as you want, throw away tons of garbage without caring of the short term consequences, because these actions have heavy long term consequences. By making them (artificially) happen sooner, the player immediately gets feedback based on their behavior. The player can then reflect on that, and understand that every action counts.
However, I would like to bring some nuance here: your game is still based on ideologies that led us to this state of the world. The goal is still to build, expand your city, add decorations (as if the world had to be shaped by us, which is truly an anthropocentric view of the world). You solve everything with money, you even buy critters, like they are in a sort of zoo, only there to serve as a decoration or object of collection. And a lot of details are omitted, like the actual cost of an electric car, which still involves some heavy industries and mining (for steel, batteries...) which highly depend on fossil fuels. And finally, it seems the game makes a focus on transportation, but it's actually not the first cause of carbon emission (which is by far energy production). Maybe all of this is made on purpose to lead the player to empty the fossil fuels reserves, which makes the gameplay change drastically ?
Maybe building a city on a desert island IS the problem, not the solution.