PORTLAND, Oregon, Oct 4 (Thomson Reuters Foundation) - Three years ago, a group of eighth graders came before Portland's City Council to ask for something unusual: a ban on new facilities to transport or store fossil fuels in the city.
Quoting Dr. Seuss, singing Bob Dylan's "The Times They Are A Changing" and performing a short play set 200 years in the future, they told the officials fossil fuels had no place in a world struggling with climate change - or in Portland's future.
Later that day, city officials unanimously voted for the first-in-the-nation ban.
"This is the first stone in a green wall of resistance against fossil fuel facilities on the West Coast," promised then-Mayor Charlie Hales, who heralded the ordinance as an example of how cities can take action against climate change.
Today, more than 70 cities around the world - including green-leaning Portland - have pledged to become "carbon neutral" by 2050, meaning they will eliminate nearly all fossil fuel emissions and offset what they cannot, through actions such as planting carbon-absorbing trees.
Each city is pushing toward the goal in its own way, to help meet the emissions-cutting goals of the 2015 Paris climate agreement, which aim to hold off the worst impacts of global warming, from fiercer storms to more frequent crop failures.
But the road to becoming a "zero carbon city" is rarely a simple or easy one, as Portland has discovered.
After passing its landmark policy, which banned construction of new, large-scale fossil fuel facilities in the city, Portland was hit by a legal challenge from petroleum trade groups and a local business coalition The groups argued the city had overstepped its constitutional bounds by effectively blocking interstate commerce, an argument the state land use court upheld in July 2017.
The city then appealed and won - a decision ultimately upheld by the state Supreme Court in July.
"We are disappointed that the Oregon Supreme Court declined to review this case," said Kara Siepmann, a spokeswoman for the Western States Petroleum Association, one of the original challengers.
"This matter remains very important to our industry, the city of Portland, and all Oregonians who rely on terminals for safe and reliable access to fuel," she told the Thomson Reuters Foundation via e-mail.
The Portland Business Alliance, another challenger, declined to comment.
The ruling now clears the way for Portland to put its new law into effect - but only after years of delay.
"People in Portland fight to defend what we love from dirty fossil fuel projects like oil train terminals," said Dan Serres, conservation director for Columbia Riverkeeper, an environmental non-government organization that joined the city's court appeal.
"The city of Portland made history when it adopted the fossil fuel ordinance. With these challenges from the oil industry and the Portland Business Alliance out of the way, Portland can move forward toward putting this policy into practice," he said.
Turning the policy into day-to-day action in the city, however, will bring its own challenges.
The ordinance calls for the city council to "actively oppose expansion of infrastructure whose primary purpose is transporting or storing fossil fuels in or through Portland or adjacent waterways".
Determining what projects do that is up to the Bureau of Planning and Sustainability.
It has modified the city's zoning code to restrict what it calls "bulk fossil fuel terminals" - facilities with the capacity to hold more than 2 million gallons (7.5 million litres) of fuels such as oil, natural gas or propane.
Portland doesn't aim to phase out fossil fuels entirely just yet.
While it pledged last year to aim for 100 percent renewable energy - on the day U.S. President Donald Trump said he would withdraw the United States from the Paris agreement - Portland for now still needs existing oil and natural gas distribution networks to heat homes and fuel automobiles.
But "we have enough," Portland city planner Tom Armstrong, who worked on the zoning code, told the Thomson Reuters Foundation in an interview.
Banning new fossil fuel infrastructure supports the city's 100 percent renewable pledge and its climate action plan. But it's also aimed at reducing another risk - from earthquakes.
"Climate action issues aside, our port facilities are not located in the best place when it comes to seismic risk," Armstrong said.
When the city studied existing riverfront oil and gas terminals, researchers discovered they all sit on land susceptible to liquefaction - when saturated soil begins acting like a liquid - during an earthquake.
With Portland situated near a major 600-mile-long fault zone off the U.S. West Coast, "zoning is about ensuring public health and safety and that's what we're trying to do in Portland," Armstrong said.
"No one wants a fossil fuel terminal exploding in their backyard," Mia Reback of 350PDX, the local chapter of a climate activist organisation, told the Thomson Reuters Foundation.
The constellation of oil tanks, propane terminals and liquid natural gas plants along Portland's Willamette River lies just a few miles from the city's downtown, with its trendy food trucks and artisanal doughnut shops.
Serres - and city planner Armstrong - say they have noticed an increase in oil trains moving through the city, some carrying fuel from Canada's Alberta tar sands bound for ships to Asia and elsewhere.
Serres believes Portland's geography at the confluence of the Willamette and Columbia rivers - along the flattest route between the Rocky Mountains and the Pacific Ocean - makes it uniquely positioned to slow down worldwide distribution of fossil fuels.
"We sit between large international markets overseas in Asia and globally significant fossil fuel reserves in the middle of the North American continent," he told the Thomson Reuters Foundation.
Armstrong does not see the city's role as disrupting that flow of commerce, "but we do have a say in how land gets used in our city," he said.
Portland is not the only city looking at the question. Vancouver, a city on the north side of the Columbia River, in the state of Washington, banned bulk oil terminals in 2016.
Other deep-water ports along the lower Columbia are also considering whether to accept facilities ranging from coal terminals to methanol refineries - but so far Portland has taken the strongest line against them.
"The Portland ordinance was the first time we saw a municipality take a big, affirmative step to say no, we're going to move in a different direction," Serres said.
Allowing the expansion of fossil fuel facilities could add cash from property taxes and business license fees to Portland's coffers. But Armstrong said he does not think the ban will have a significant financial impact on the city.
What is more worrisome is the relatively slow progress toward the city's 100 percent renewable energy pledge, local climate activists say.
They are pushing a citizen's initiative on the November election ballot that would tax businesses to create a $30 million annual clean energy fund for the city.
The money would pay to install rooftop solar arrays, weatherize homes, and offer job training in green energy fields. "This is not yet reality - and is only a piece of what's needed from the city," said 350PDX's Anais Tupeker.
Reporting by Gregory Scruggs; editing by Laurie Goering.
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