President Trump sought to promote an area hungry for investment Tuesday by showcasing growing efforts to capitalize on western Pennsylvania’s natural gas deposits by turning the energy source into plastics.

Trump traveled in Monaca, about 25 miles north of Pittsburgh, to tour Shell’s soon-to-be-completed Pennsylvania Petrochemicals Complex.

“This would have never happened without me and us,” said Trump, who spoke to a crowd of thousands of building workers dressed in fluorescent orange and yellow shirts and vests.

Trump's visit was in keeping with an ongoing push by his administration to increase the economy’s dependence on fossil fuels in defiance of increasingly urgent warnings about climate change. It also represented an embrace of plastic at a time when the world is sounding alarms over its ubiquity and impact.

Critics of the Shell facility, which the oil and gas company announced in 2012, claim it will be the largest air polluter in western Pennsylvania.

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Trump’s appeals to blue-collar workers helped him win Beaver County, where the plant is located, by 18.5 percentage points in 2016, only to have voters turn to Democrats in 2018′s midterm elections. In one of a series of defeats that led to Republicans’ loss of control of the House of Representatives, voters narrowly sent Democrat Conor Lamb to Congress in a special election.

Beaver County is still struggling to recover from the shuttering of steel plants in the 1980s that surged the unemployment rate to nearly 30 percent. Former mill towns like Aliquippa have seen their populations shrink, while Pittsburgh has lured major tech companies like Google and Uber, fueling an economic renaissance in a city that reliably votes Democratic.

The region’s natural gas deposits had been seen, for a time, as its new road to prosperity, with drilling in the Marcellus Shale reservoir transforming Pennsylvania into the nation’s No. 2 natural gas state. But drops in the price of oil and gas caused the initial jobs boom from fracking to fizzle, leading companies like Shell to turn instead to plastics and so-called cracker plants — named after the process in which molecules are broken down at high heat, turning fracked ethane gas into one of the precursors for plastic.

Shell was given massive tax breaks to build the petrochemicals complex, along with a $10 million site development grant, with local politicians eager to accommodate a multibillion-dollar construction project.

Trump defended the investment in plastics, claiming pollution in the ocean is “not our plastic.”

“It’s plastics that’s floating over in the ocean and the various oceans from other places,” he told reporters before boarding Air Force One.

A pro-fracking trade group said it would “applaud” the administration’s energy policies.

“Affordable, abundant, local natural gas is powering a Rust Belt revival, as the region looks to gain a competitive edge in attracting advanced manufacturing - and the good-paying jobs that come with it,” Marcellus Shale Coalition president David Spigelmyer said.

The project currently has 5,000 construction workers. Once operational, however, the site will employ far fewer — 600 — permanent employees.

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And the area still faces other headwinds. The nearby Beaver Valley Power Station, a nuclear plant that has employed 850 people, has announced plans to close in 2021. And the Bruce Mansfield Power Plant, once the state’s largest coal-powered plant, announced Friday that it would close this fall, 19 months earlier than expected, at a cost of at least 200 jobs.

The Associated Press contributed to this report.