Pumping system and method

A pump assembly comprising:

• a plurality of systems, including a first system and a plurality of second systems, each of the plurality of systems containing an enclosed gas placed in contact with an internal liquid, the enclosed gas being placed at a depressed pressure or at a raised pressure in relation to the pressure of surroundings external to the plurality of systems by variations in level of the liquid;
• and
• a plurality of tubes, each of the plurality of tubes extending between adjacent systems of the plurality of systems with a first open end terminating in one of the adjacent systems and a second open end terminating in the other of the adjacent systems,
• wherein:
• the first system is in liquid communication with an external liquid below a ground surface, and is configured and located to create compression of the gas enclosed in the first system relative to the pressure of the surroundings external to the first system;
• each of the plurality of second systems is closed and isolated in terms of the enclosed gas in contact with the internal liquid therein;
• and
• respective liquid environments of the plurality of systems are connected continuously by the plurality of tubes so that compression of the gas enclosed in the first system leads to successive incidences of increased pressure to the gases contained in the plurality of second systems, thereby delivering work to cause pumping of the external liquid in contact with the internal liquid of the first system through the plurality of second systems.