Canada's annual heat-trapping greenhouse gases continue to level off or decline in most sectors of the economy, outside of Alberta's oilpatch, says the latest annual inventory report submitted by the Harper government to the United Nations.

The submission, which covers annual emissions across the Canadian economy from 2011, revealed a 0.14 per cent increase in emissions to about 702 million tonnes. But the levels remain about five per cent below 2005 levels, due to structural changes in the Canadian economy that is moving from producing goods to providing services, as well as some federal and provincial policies, the report said.

"Under the previous Liberal government, greenhouse gas emissions actually increased by a staggering 30 per cent," Environment Minister Peter Kent told Postmedia News in an email.

"We were the first government in Canadian history to reduce greenhouse gas emissions."

The statistics and analysis is mandatory under the United Nations Framework Convention on Climate Change, an international treaty that came into force in 1994 to prevent greenhouse gases from causing dangerous interference with the atmosphere.

The government report, prepared by Environment Canada, noted the country's average temperatures were 1.5 degrees C above average in 2011, which makes it more likely to observe impacts such as rising sea levels and increasing extreme weather events that could intensify in the future.

"In some regions, the impacts could be devastating, while other regions could benefit from climate change," the report said.

The emissions contributing to those changes in Canada were stabilizing or declining in some sectors due to a mix of federal and provincial policies, including Ontario's efforts to phase out coal-fired electricity plants and federal fuel economy standards for vehicles that were spearheaded by the Obama administration in the United States.

But oilsands companies exploiting Alberta's natural bitumen deposits, which require large amounts of energy and water to extract heavy oil, continue to be the fastest growing source of greenhouse gases in the country, standing in the way of Prime Minister Stephen Harper's target to lower annual emissions by 17 per cent below 2005 levels by 2020. A report released by Environment Canada in August estimated Canada was on pace to be about 20 per cent above that target in 2020.

The oilsands sector also now represents about eight per cent of Canada's overall annual emissions.

The report said Canada had the largest growth in emissions among G8 countries over the past two decades. It is also among the top sources of greenhouse gases in the world, representing about two per cent of global emissions, and one of the highest sources of greenhouse gases per person.

The oil-sands industry has seen its greenhouse gas emissions grow from 15 million tonnes of carbon dioxide equivalent gases in 1990 to 55 million tonnes in 2011, and Kent has pledged to introduce new regulations by the middle of this year for the oil and gas sector.

Oilsands industrial activities have reduced emissions per barrel of oil produced by about 26 per cent since 1990 because of new technologies, as well as exporting some emissions to the U.S. for some refining and upgrading activities.

Other figures from the report show that Alberta's industrial facilities are responsible for 48 per cent of all industrial emissions in the country in 2011, followed by Ontario at 19 per cent, Saskatchewan at nine per cent and Quebec at eight per cent.