It could be that consciousness is simply an emergent property (a by-product) of the communication of billions of neurons that are connected in trillions of ways. Where neurons are emergent of chemical phenomena which are emergent of atomic phenomena and so on.
I'm probably greatly simplifying the dependencies of phenomena, but I think that consciousness is most definitely based upon physical processes. The current evidence makes me believe that consciousness is a by-product of evolution, which is a by-product of the conditions on our planet.
So it goes.