For all intents and purposes the Earth IS considered a closed system. AND the entropy laws [not theory] have been proven many times and in many ways hence that is why they are laws.
“For all intents and purposes the Earth IS considered a closed system.”
I’m a creationist, but this is simply not true. The earth constantly receives energy from the sun, so it cannot be considered a closed system, anymore than a cupcake inside an oven can be considered a closed system.
Only if our planet were floating in deep space far from any external source of energy would it be feasible to consider it to be a closed system.