Let's say that one day an advanced alien civilization comes to Earth and for reasons unknown, they want to save the Earth's ecosystem and biosphere and help humans develop into the next stage of civilization. How exactly would they do that?
I've though of it myself though and there are many things that seems to be a problem. First of all, I think its very clear that many nations would be shocked and paranoid by the mere existence of the aliens, and with that chaos going on, it's reasonable to assume that some nation will probably assume that the aliens are a threat and try to nuke them (Looking at you North Korea). That would make it more difficult for the aliens to help us and perhaps piss them off enough that they'd try to destroy us instead.
And even if the world decided to accept their help, I think the governments wouldn't really listen to the aliens.
The aliens would probably know that in order for the world to get better, humans have to get better as well and assuming that the aliens decide not to brainwash us or something that would be extremely difficult. Given man's nature, humans aren't the most welcoming beings when it cones to change, And that counts for saving the environment as well.
I'll give an example: One of the aliens says to the humans that they should stop using fossil fuels because it destroys the environment and instead they will give us a new form of energy. Of course, there's a problem: if the fossil fuels factories close the companies, and therefore the government, will lose money. The companies wouldn't accept that and most likely they would hire someone to kill the alien before it convinces anyone to use the new energy.
So my question is, "If the aliens were determined to help our planet and species, how would they go about it?"
Note: Brainwashing our species or using force is not an option.