The city will ask the Federal Court of Appeal on Friday for a judicial review of the National Energy Board process for the project.
Vancouver officials already asked the board to take climate change into account but the regulator decided in July it would not.
Now the city wants the court to decide, said Sadhu Johnston, deputy city manager.
"What we're trying to do is to ask the NEB to have a thorough review of this, that evaluates not just the economic benefits but evaluates the environmental impacts," Johnston said Thursday.
The $5.4-billion project would almost triple the capacity of the current pipeline linking the Alberta oilsands to Kinder Morgan's terminal at Port Metro Vancouver, increasing flow from 300,000 barrels of oil a day to almost 900,000.
"The city of Vancouver is the largest port city in the country and we have a lot of coastline. We are already being impacted by changing sea level," Johnston said.
"We are directly impacted by the burning of these fossil fuels and we believe that does need to be taken into account - the cost of that and the implications of that."
The Trans Mountain project faces some staunch opposition at the end of the line in Metro Vancouver.
The city of Burnaby fired its own salvo Thursday in its dispute with Kinder Morgan over access to city land.
The company would prefer to bore its pipeline through the mountain, rather than follow the current pipeline route through residential and business areas but Burnaby has refused access.
Earlier this week the National Energy Board released a decision saying that, under federal laws, Kinder Morgan doesn't need permission to access the land that is home to Simon Fraser University and a vast nature preserve.
Burnaby responded by saying the energy board decision was limited to its rights as a private landowner — not its jurisdiction as a regulator.
"Accordingly, we wish to advise you that Burnaby regards their bylaws and regulatory policies over public lands, parks and conservancies as continuing to have effect," Bruce Rose, the city solicitor, wrote in a letter to Kinder Morgan Canada.
The company will have to complete an application for access and will get a decision "as soon as practicable."
Proceeding without city permission could lead to charges for breaching city bylaws, the letter warned.
The dispute has already caused a seven-month delay in the regulatory process.
The board panel will not have its final report to cabinet until Jan. 25, 2016. Under the original schedule, the report was due July 2, 2015.
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