I believe the managers play the mail role to green supply chain and therefore their believes and values will have dramatic effect on the organisation culture and policies.
the employees may be will have some effect in the implementation of the green supply chain policies
The nature of the organization can determine the extent of the influence of the manager, If the manager has high influence on the organization, then the perceptions and personality of the manager will go along way to influence policies of which green supply is one. Manager approves takes and approves decisions in the organization, therefore his perception counts to a large extent on the policy of green supply chain