Everyone is partially correct. A slight misunderstanding of aerodynamics and how lift is actually created. For lift to be created there must be a) motion - either a solid object moving through a gas, or gas flowing over a solid object (in most cases, we would think of a wing being the solid object here), b) there must be a medium (a fluid or a gas) in which the solid object is moving through or being passed. It does not require a pressure gradient to exist already. Lift creates a pressure gradient. Atmospheric pressure gradients do not create lift. Does this clear up any confusion?