A319
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution
Aircraft
Climbing out enroute [4 hour flight]; lost yellow hydraulic system. After short discussion decided that returning with overweight landing was safest course.
A319 First Officer experiences the loss of the Yellow Hydraulic system during climb out.  The crew elects to return to the departure airport.