So I'm thinking, everything we create is sourced from the earths environment. At a molecular level, are we not replacing molecules with molecules, and despite the fact we've covered the place with heavy objects (buildings, cars and ikea furniture) that are made from "man made" materials, it's the same weight?
My secondary question related to the same subject, it's that if there is excess weight being placed on the planet, surely this has some impact on the Earths gravitational rotation and therefore via momentum, it's position on space. So, could it possible be that we could accidentally - by manufacture - cause the Earth to be slung out of orbit when it reaches some kind of critical mass to overcome the current principles?
What can I say, my mind works in mysterious ways.