The Canadian Press/Andrew Vaughan A protest sign put up by Stop Energy East Halifax outside the library in Halifax, Monday, Jan. 26, 2015. TransCanada has cancelled the Energy East pipeline, a move hailed by climate groups.

As Canada's politicians threw blame around in the wake of TransCanada's cancellation of the Energy East pipeline, environmental groups hailed the decision, and called it a sign that the age of oil is coming to an end. "The message from today's cancellation of TransCanada's proposed Energy East pipeline is loud and clear," the group Environmental Defence said in a statement.

"New tar sands pipelines don't make sense — economically or environmentally — in a world that is addressing climate change and moving away from fossil fuels." Greenpeace took a similar tack, calling it "a great day for our water, climate and economy, and for Indigenous rights. The world is changing and the end of the age of oil is in sight." TransCanada announced Thursday morning that, due to "changed circumstances," it won't be going forward with the Energy East and Eastern Mainline projects, which were to take 1.1 million barrels of oil per day from Alberta to ports on the east coast of Canada. The company had announced last month it was suspending its efforts to get regulatory approval for the projects.

Bloomberg via Getty Images TransCanada CEO Russ Girling did not specify the reasons for the company's cancellation of Energy East, but climate groups say it was at least partly due to tougher new environmental review standards for pipelines.

TransCanada did not specify reasons for the cancellation, but the industry has been rocked by persistently low oil prices in recent years, and Energy East faced a mass of political opposition, particularly in Quebec and from Indigenous groups. But in a statement Thursday, the environmental group Sierra Club said the decision had to do with a tough new environmental review process at the National Energy Board (NEB). In assessing a pipeline's environmental impact, the NEB had previously only considered the greenhouse gas emissions created by the construction of the pipeline itself. Watch: France aims to ban all fossil fuel production by 2040

But in August the board announced it would now also count upstream and downstream emissions, meaning emissions at the site of production, and emissions created by the burning of the oil that passes through the pipelines. That decision was met with heavy criticism from the oil industry and its supporters, and applause from the climate activists who had pushed for the move. Sierra Club gave some credit to climate groups for TransCanada's decision. "TransCanada's statements indicate that new criteria Sierra Club members and thousands of Canadians pushed for ... shaped its decision to cancel the project," the group said in a statement. Opposition Conservatives on the attack The cancellation quickly became fodder for the Opposition Conservatives, who on Thursday laid the blame with the federal Liberals. "Today is the result of the disastrous energy policies promoted by Justin Trudeau and his failure to champion the Canadian energy sector,'' deputy Conservative leader Lisa Raitt told a news conference on Parliament Hill. She said new regulations on Canadian energy projects, brought in by the Liberals, have put Canadian energy companies at a competitive disadvantage.

THE CANADIAN PRESS/Adrian Wyld Conservative MP Lisa Raitt rises during question period in the House of Commons in Ottawa, Wed. Oct.4. Raitt has blamed the governing Liberals for TransCanada's cancellation of the Energy East pipeline.