As a hypothetical, say it became easy to grab water from objects in space and then move it places that needed (Africa / the gulf). What would the end results be for the global climate over time? Would you just end up with a flooded earth? Would temperatures rise or fall as time goes on?
Extrapolating a bit, what if we brought in enough water to cover the entire current exosphere? Or if you added enough water that the planet engulfed the moon? How would the water behave at those extreme pressures? What would happen to the landmasses beneath it?