[quote=@thatguy]
Could there be an alien presence on Earth similar to National City from Supergirl's CW show or have Knowhere orbiting the planet and i could have the team be grounded? 
[/quote]

Knowhere coming to earth is one of those things where the story would have to happen IC as it would be a pretty significant thing to happen. Same as with Matt and he lanterns so long as the threats aren't world ending I don't see an issue with them being trapped on Earth/on earth for a specific purpose.