Is there a mod or anything that just gets rid of pollution?
The stability the tree planting and all this is quite ridiculous I just want to build and make a great empire without dealing with the pollution for once with my friends in a multiplayer game.

Just take the pollution as a challenge you should play with, like ennemies empires is a challenge ;) 
I think its a great think to add the pollution in a game like this : the fact is that the planet as severals limits, overshoot them logically drive you to an collapse if you dont manage them.

Unfortunately, there isn't much that can be done to reduce pollution, much like in real life. Over time, pollution will naturally fade, albeit somewhat slowly.

1v1 battle

Natural reserves can help quite a lot with pollution ; in my last game, with the help of renewable energies, I manage to have a global negative amount of pollution, without sacrifying my production.

And, in order to respond to your demands, nope, I don't think there is a mod to get rid of pollution.

There are mods that reduce pollution, don't know if any completely eliminates it. Just search "pollution" in mods.

Hey there 

You can still deactivate its effects in the endgame conditions. Pollution will still exist but it won't be a threat anymore

Have a very nice day

Ben