A Tower Controller in Charger reported the Local Controller assigned an altitude to a departing VFR aircraft that placed it in unsafe proximity to nearby terrain.

Narrative

RWY XX/XY in use. I was operating as CIC (Controller in Charge); with a CPC certified less than a year working at Local Control (LC). LC departed a P28A; off Runway XX with a right turn to the NW. I observed an Aircraft Y 14 miles to the south of ZZZ on a right downwind which is the most common pattern entry for IFR a/c (Aircraft) into ZZZ in this configuration. I queried LC as to the plan for the P28A and how they would resolve the conflict. LC visibly tilted their head in thought; without responding to me; and issued an eastbound turn for the P28A; directly away from their intended destination of ZZZ1. The P28A readback the instruction; and I called the LC attention to the fact that the P28A was not turning and was almost clear of the Class D and would not have to listen to our instructions. LC confirmed with the P28A that their intended destination was to the NW; ZZZ1; and issued 'Maintain VFR at or below 025'. I told LC that was not safe and they would need higher for the terrain at the P28A 12 o'clock and 3 miles that the peak was at 022. LC disregarded my statement; and issued to Aircraft Y to 'Maintain at or above 030'. The P28A continued for another 2 miles while Aircraft Y was beginning the descent down to 030. The P28A; now within 2 miles of the depicted peak requested higher for the terrain. Aircraft Y at 041 depicted with a 12 second sweep between updates was able to maintain at or above 035; and LC issued at or below 030 for the P28A; resolving the safety issue. When questioned if the LC was aware of the height of the peak; LC responded that they were and that the P28A would request higher if they were unable to maneuver safely as they did.I believe that this is not requiring an airspace or procedure change; but re-training the LC CPC as information was offered from the CIC and it was ignored; as well as being aware of the terrain heights depicted.