"The federal government does not have an overall plan that maps out how Canada will achieve this target, and Canadians haven't been given the details about which regulations will be developed, when nor what greenhouse gas reductions will be expected."
Washington, meanwhile, has said it would meet its target and is already planning deeper cuts post-2020.
Environment Canada forecast that the Canadian oil and gas sector's contribution to national emissions will rise to 200 megatonnes by 2020.
This is 27 megatonnes more than in 2012 and a larger increase than any other sector.
"Despite this prediction, regulations for the sector have been repeatedly delayed," said Gelfand in her report.
The report also says the government could do more to monitor the impact of developing the Alberta oil sands on air and water quality, and biodiversity.
Ottawa also could make marine navigation in the Canadian Arctic safer and minimize environmental risks, she said, by deploying more icebreakers and improving navigational charts.
Copyright Agence France-Presse, 2014