Good day,
This is in response to your email requesting information on the signatures of Governor Mark Carney.
All bank notes issued by the Bank of Canada bear the signatures of the Governor and Deputy Governor who are in office at the time the notes are printed. So when the people in these positions change, so do the signatures. However, new notes are not necessarily printed as soon as a new Governor or Deputy Governor is appointed. The Bank has to first deplete its stock of existing notes before it prints new ones. Therefore, it may take some time before bank notes with new signatures are put in circulation, depending on demand and existing stock.
I hope this information is helpful and thank you for your interest in Canadian currency.