Prime Minister Justin Trudeau says it was the Alberta government's leadership role in tackling climate change that allowed him to approve two major pipeline projects.

He said that without the carbon tax introduced by NDP Premier Rachel Notley, Ottawa would not have been able to justify green-lighting the Kinder Morgan Trans Mountain pipeline expansion and Enbridge's Line 3 project.

"The fact that we are able to move forward on approving two significant, important pipeline projects for Alberta was directly linked to the leadership this Alberta government has shown … around the impacts of climate change," he told reporters in Calgary.

The prime minister spoke earlier in the day at the Calgary Chamber of Commerce year-end breakfast.

Trudeau said opposition parties in Alberta that have vowed to scrap the carbon tax — which comes into effect Jan. 1 — don't understand the new political dynamics at work.

He said putting a price on carbon and capping carbon dioxide emissions from the oilsands are necessary measures for Canada to move ahead with big projects such as pipelines, while still protecting the environment.

"Quite frankly, the fact that there are a number of opposition politicians out there who bizarrely seem to be crossing their fingers that these pipelines will not get built under this current government, I think, is really dismaying, and should be dismaying for Albertans," he said.

Trudeau said his predecessor, Stephen Harper, who claimed to be a champion for Alberta's energy sector, was unable to deliver on pipeline approvals because he, too, refused to accept that getting energy resources to market in the 21st century requires responsible leadership on the environment.

Wildrose MLA and energy critic Drew Barnes countered his party is "a huge supporter of pipelines," but said they are against any carbon tax.

"I'm disappointed to hear the prime minister say that, he either misunderstands or he's wrong," he told CBC News.

"Absolutely the Wildrose is a supporter of pipelines in all directions. We're a huge supporter for jobs and opportunity for Albertans. Yeah, we have some concerns about the carbon tax, we're an energy producing jurisdiction... we're very, very fearful it's going to impact investor confidence and Alberta families tremendously."

Keystone back on agenda

During a question and answer session following his speech at the chamber, Trudeau said he supports a renewed push to get the Keystone XL pipeline built, a project U.S. president-elect Donald Trump has vowed to approve shortly after he takes office.

Trudeau told the business audience that he and Trump discussed Keystone in their first conversation after the U.S. election.

"He actually brought up Keystone XL and indicated that he was very supportive of it," Trudeau said during a question-and-answer session after his speech.

"I will work with the new administration when it gets sworn in ... I'm confident that the right decisions will be taken."

The 830,000 barrel per day pipeline would carry oilsands crude from Alberta to the U.S. Midwest. It was rejected by the Obama administration last year.

Trump has previously said he would approve the pipeline but wanted a "better deal" for the United States.

Trudeau said if the United States takes a step back on fighting climate change under Trump, Canada will capitalize.

Climate change is a fact and fighting it is where the rest of the world is going, he said.

And while there might be short-term benefit in ignoring it now, he said, if Canada sticks to its plan, the country will be attractive to investors who are looking decades down the road.

Pipelines safer than rail, PM says

Trudeau said moving crude oil via pipeline is safer for the environment and more economical than moving it by rail.

Almost all of Canada's oil is currently exported to the U.S. Pipelines that carry oil from Canada are at capacity, so a lot of it is going by rail. Canadian oil also faces a significant discount in U.S. Midwest refineries because it's heavier and more expensive to refine than light crude.

Alberta's premier could find herself at odds with both Trudeau and Trump on the issue of Keystone, said Duane Bratt, who teaches policy studies at Mount Royal University in Calgary.

"She hasn't said a word, one way or the other, about Keystone, since the American election. And she had always been opposed to it," he said.

"It was easy to be opposed to it when you saw that Obama was about to get rid of it."

Calgary on Ottawa's mind

Trudeau said his government's decision to green-light Trans Mountain and Line 3 shows that Calgary is top of mind in Ottawa under his leadership.

"What happens in Calgary is important. It's important to Alberta and all of Canada," he said.

"And as I said in making the announcement, these approvals are a major win for Canadian workers, for Canadian families and for the Canadian economy."

Trudeau said the projects will create upward of 22,000 jobs and demonstrate to Canada and the world that responsible resource development can happen in concert with solid environmental protections.

"That way of thinking, that we have to choose between growing the economy and protecting the environment, simply doesn't work," he said.

Cheers from business crowd

Speaking ahead of Trudeau's address, Calgary Chamber of Commerce president Adam Legge drew a round of applause from the business crowd as he praised the Liberal government for approving Line 3 and Trans Mountain in the face of stiff opposition from environmentalists.

"We thank you for your leadership and your courage in that decision," he said.

"Getting more resources to market was a critical missing element of our national infrastructure. We are all buoyed by this decision and are ready to get to work."

Tyrone Cattleman, a member of the local plumbing and pipefitting union who came to hear the prime minister speak, said he's optimistic about the new pipeline projects.

"I really hope he goes through with those plans, to create more jobs for the younger generation," he said.