Russell Bennett, B.Sc., LL.B. from Cannabis Law has started a petition to the federal government of Canada.
https://petitions.ourcommons.ca/en/Petition/Details?Petition=e-3752
The petition is asking that the government grant automatic expungements (not pardons) to all Canadians with criminal records from cannabis-related offences, because the law never should have existed in the first place.
You can read the full details of the petition and sign your name at the link:
https://petitions.ourcommons.ca/en/Petition/Details?Petition=e-3752