South African Archbishop Desmond Tutu has described Alberta’s oilsands as “filth,” saying its production is a result of “negligence and greed.”

Tutu was the keynote speaker on Saturday at a conference in Fort McMurray, Alta., focused on oilsands development and aboriginal treaty rights. The 82-year-old -- who won the Nobel Peace Prize for his work in the battle against apartheid in South Africa -- spoke to a room of about 200 people, including First Nations members.

“The fact that this filth is being created now, when the link between carbon emissions and global warming is so obvious, reflects negligence and greed,” he said. “The oilsands are emblematic of an era of high carbon and high-risk fuels that must end if we are committed to safer climate.”

Tutu, who has called on people to boycott fossil fuel companies, said he stands in solidarity with communities that are opposed to oilsands pipeline projects, such as Keystone XL, Northern Gateway and Energy East.

“Oilsands development not only devastates our shared climate, it is also stripping away the rights of First Nations and affected communities to protect their children, land and water from being poisoned,” he said.

Tutu’s remarks on Saturday were not the first time the archbishop has taken a strong stand on climate change.

In an opinion piece published earlier this year in The Guardian, Tutu referred to the Keystone project, which proposes to move crude oil from Alberta to the U.S. gulf coast, as appalling. He is part of a growing chorus of other high-profile figures, such as Canadian rocker Neil Young, who say projects like Keystone pose a serious risk to our environmental safety.

Industry supporters of Keystone, however, have pointed out that the oilsands’ contribution to global warming is miniscule. They also say that there is a growing demand for energy across North America.

“As we know, the world needs an energy mix, developed responsibility, in order to meet global energy demands,” Geraldine Anders, a spokesperson for the Canadian Association of Petroleum Products, told CTV News on Saturday.

In response to Tutu’s comments on Saturday, TransCanada, the company that wants to build Keystone, said oil and other fossil fuels have helped to improve the lives of people around the world.

“Oil powered the jet that flew Mr. Tutu from Canada to Africa, produced the fuel for the helicopter tour he had planned of the oil sands, and helped manufacture the microphones and TV cameras for his press conference,” Davis Sheremata, a spokesperson for TransCanada, told The Canadian Press in an email. “Without oil, we wouldn’t have fertilizers to grow our food, plastics for surgical tape and heart valves, and gasoline to start the more than 250 million cars in North America every morning.”

The Keystone XL pipeline was stalled after the U.S. State Department announced in April that it wants to give federal agencies more time to review the $5.4-billion proposal by TransCanada.

The 2,700-kilometre line would move bitumen from Alberta’s oilsands to refineries on the Gulf Coast of Texas.

According to supporters of the project, the pipeline will create thousands of jobs on both sides of the border, and offer an efficient and safe method of transporting large volumes of oil.