MITCHELL: This is the central waterfront.

This is Pier 3 right here.

This is the state pier.

O'BRIEN: And yet, the skepticism that persists about the urgency of the climate crisis and the wisdom of building offshore wind makes Mayor Mitchell's job a little harder.

MITCHELL: This is the biggest fishing port in America.

O'BRIEN: But he gets it.

He, too, was a wind skeptic at first.

MITCHELL: I thought it was, like, this European thing, like Nutella-- it sounded good, but didn't really, didn't really know whether, what to, what to make of it, right?

O'BRIEN: He realized the pro-wind argument had to be about the economy.

As much as I embrace the idea that offshore wind can be part of the solution for, in our efforts against climate change, our work here has been primarily about economic development.

O'BRIEN: You're really remaking this port, aren't you?

MITCHELL: Yeah.

We really are.

O'BRIEN: It's pretty significant.

You got construction all up and down this harbor, so, what's the total dollar amount right now?

MITCHELL: It's about a $1.1 billion.

O'BRIEN: Would that have happened without wind?

MITCHELL: A lot of it wouldn't.

In fact, most of it would not.

We're trying to modernize the port for any industry that can use it well.

Any industry that can gain an advantage, invest here, create jobs, that's the idea.

O'BRIEN: He showed me the huge Marine Commerce Terminal where the wind turbines were being staged.

Nearby we saw a pier built in the 19th century to support the whaling fleet.

Later, it was home to a coal-fired power plant.

So from whaling to coal to offshore wind, the full-- it's all right there.

Run the gamut.

There's something compelling about the fact that we're leading the way in this brand-new energy industry that will contribute positively to America's efforts against climate change.

O'BRIEN: New Bedford has a geographic advantage.

It's close to the major wind energy areas-- and it has a seafaring workforce.

INSTRUCTOR: Swim over to the platform.

O'BRIEN: Although the workers are new to offshore wind, the city is now home to the country's first offshore wind training site.

INSTRUCTOR: Now let it go, here we go.

(water splashing) O'BRIEN: 21st-century jobs in a city written off in the latter half of the 20th century.

Are you worried at all that offshore wind is still, if you'll excuse the expression, not on firm ground politically and otherwise?

It is here in the United States.

It's here to stay.

There's just too much that's been sunk in the way of major investment for it to stop entirely.

The horse is out of the barn in offshore wind.

It's a question of how rapidly that horse is going to run at this point.

♪ ♪ O'BRIEN: But the mayor is also navigating some tricky political shoals right here on the waterfront.

With all the factories shuttered, commercial fishing is the largest industry in New Bedford.

In fact, it's the most lucrative fishing port in the United States, catching between $400 to $500 million worth of seafood each year.