As Paula noted earlier, the cabinet directive applies to all ministers, and through them, to their officials. The Privy Council Office has overall oversight for implementation through memoranda to cabinet and other mechanisms. She spoke to the cross-link at several stages with the federal SD strategy. In the new act, there's a specific reference to the role of Treasury Board, and specifically the secretariat, in terms of the greening government operations part and their role.
On November 2nd, 2017. See this statement in context.