The effect will never be global if the West doesn't start first, because the developing countries will never accept to hurt their economic development for something the rich countries isn't doing.
But if the West starts, the rest of the world will follow, because their elite want to be like us: it is a status symbol! That's why for instance the elites in Southern countries wear western clothes despite their obvious inappropriateness to the weather. That's also why many dictators out there pretend to be “elected presidents”: because being a “president” is what makes you look like you're an western ruler.
Humans are social animals, and status is probably the strongest driver for our behaviors.
The day the West is all green, you can be sure that every country leader elsewhere world is going to flex about how green their country is too. The problem right now is that the West is all about green-washing, and so are they.