A Production Possibility Curve is the curve which shows various combinations of two goods that can be produced with available techniques and with given amount of resources, which are fully and efficiently employed. It depicts a society's menu of choices of these two goods. It tells us that if the economy wants to produce more of one commodity, it will have to transfer or divert resources from the production of another commodity to the production of this commodity. That is why the production 'possibility curve' is also called 'transformation curve'.
Enviromental determinism is causing social development. Possiblism limits human actions. Therefore both can connect to humans. So you got the differences AND the similarity if you are confused. Sorry if i wasn't helpful!
Possibilism is the belief that anything is possible. Meaning given whatever environmental conditions we are able to overcome them through knowledge, skills, technology and money. Environmental Determinism is when the conditions in the environment tell us what we are capable of doing.