Constitutionally the federal Parliament has jurisdiction only over, as I mentioned, that absolute-floor minimum age below which there can be no marriages, so there really is no constitutional way to do that. The government would have to set the age at either 16 or 18. In either instance, there would be no marriages possible below it, but it's within provincial jurisdiction to deal with what happens above it up to the age of majority.
On March 31st, 2015. See this statement in context.