WASHINGTON (Nexstar) — Mayors who are leading the way in efforts to reduce pollution and fight climate change were invited to Washington DC to share their ideas about how similar efforts can be implemented nationally.

“We’ve done it while our population has ballooned and our economy has thrived,” Portland Mayor Ted Wheeler said. “So the first message I want to get across is that you can in fact be a thriving community and achieve your sustainability goals. They’re not mutually exclusive.”

Wheeler said Portland has been leading the way on reducing carbon emissions by incorporating green transportation by encouraging people to walk or bike to work.

He said it’s possible to duplicate that nationally if the government provides safe infrastructure for cyclists and pedestrians and fast, affordable, convenient public transportation.

He also has ideas for how to pay for it.

“Tolling on federal roadways,” he said. “Right now there’s a prohibition against tolling on federal roadways that are in existence.”

Honolulu Mayor Kirk Caldwell was invited in part because his city created a permanent climate change office and Honolulu is committed to planting 100,000 trees by 2025 and taking steps to deal with rising sea levels.

“We’re raising buildings in the urban core, but we’re retreating from the ocean and areas where we let the beach erode,” Caldwell said.

The mayors spoke to a room full of Democratic senators but in order to pass any federal climate legislation, Republicans would need to be on board too.

“It’s not a Republican issue or a Democrat issue, it’s an issue for our time its an issue for our children and I would only hope that republicans would come on board to this committee,” Caldwell said.