Mark Carney is a Canadian who is the current Governor of the Bank of England. Prior to this he was Governor of the Bank of Canada and in that capacity he signed banknotes.
Canada's currency is now all plastic and the 5 dollars was the last denomination to be issued in plastic, just before Carney came to Britain to take up his new post. Plastic 5 dollars are elusive because they appeared for such a short time.
Crisp uncirculated condition (P.106)