Putting a limit on the amount of emissions coming from oil sands production would show Alberta can strike the proper environmental balance, its government said.

Alberta is the center of the Canadian oil sector. Total oil production for July, the last full month for which data are available, was 91 million barrels, about 5 percent less than last year. So-called non-conventional oil, or oil sands, production accounted for more than 80 percent of all the oil produced in Alberta.

Production of oil sands is controversial because a number of studies have concluded it's more carbon-intensive than some of the lighter grades of oil found in the Lower 48 U.S. states. Alberta Environment Minister Shannon Phillips introduced the Oil Sands Emissions Limit Act that could cap emissions, but make some allowances for new work.

"Putting a limit on oil sands emissions shows how Alberta can be an energy producer and a world leader on climate action," she said in a statement.

The cap of 100 megatons was proposed following recommendations from environmental groups and those representing the oil sands industry. The provincial government said the proposal would allow the industry to grow, but in an environmentally sustainable way.

The Canadian Association of Petroleum Producers said that, since 1990, the sector has spent more than $1 billion on technologies needed to produce oil with a lower environmental footprint. It said greenhouse gas emissions are 30 percent lower per barrel than they were in 1990.

The government in September approved three oil sands developments, two of which involved the use of steam stimulation.

Collectively, the government said the projects represent about $3 billion in investments into Alberta's economy. They each fall under an existing scheme aimed at limiting the amount of greenhouse gas emissions associated with oil sands developments.

There is no mandated limit for oil sands emissions from Alberta.