American governors and mayors, including Boston Mayor Michelle Wu, convened at a Vatican climate conference in May to discuss ways they’re building resilience to the effects of climate change.

Three weeks later, one of the invited speakers — New York Gov. Kathy Hochul — put Manhattan’s long-awaited congestion pricing plan, which had been scheduled to start June 30, on an “indefinite pause.”

“It was a big shock to read what had happened,” Wu told Boston Public Radio during “Ask the Mayor” on Tuesday.

Congestion pricing has been heralded as a major climate step to reduce air pollution and dependence on cars. Boston City Council has debated the merits of tolling cars during peak traffic hours in order to reduce traffic. New York would have served as a “proof of concept” for cities like Boston, Wu said.

Despite the shelving of New York’s plan, Wu said she still thinks congestion pricing could happen here.

“I think all tools should be on the table, including congestion pricing,” she said. Wu said the key to congestion pricing is a reliable transportation system that provides alternatives to driving. Yet, Boston’s MBTA has faced myriad issues.

During her Boston Public Radio appearance, Wu also addressed the Boston real estate transfer tax that the Massachusetts Legislature is evaluating. Boston’s proposal would apply a 2% fee on the portion of a home’s price above $2 million. Property sales of $2 million or less would be exempt. This fee would provide revenue for affordable housing services.

“I know sometimes it feels like any additional cost is a burden, and I completely respect that,” Wu said. “This is part of making sure that we can be a livable city, not just for those who currently have a place in Boston, but for all future generations as well.”

A similar program in Gov. Maura Healey’s housing bond bill, which would give communities the option to tax real estate sales over $1 million, was eliminated in the bill passed by the House of Representatives last week.

As Boston City Council addresses the budget, Wu said her administration is looking at new ways to increase revenue by revamping the payment in lieu of tax (PILOT) program. These are voluntary payments from not-for-profits like schools, hospitals, museums and religious buildings.

“It’s basically just a pretty-please from the city to go above and beyond what is not legally required at all. … They don’t have any obligation to pay the city or public entities in taxes,” Wu said. These payments feed into the city budget that is then used to support these institutions, she said.

Wu said she’d like to move toward a system where cultural organizations “are directly opening doors and contributing to young people and families, but without making that cash payment.”

For universities, Wu said she is working to clarify to institutions how payments will benefit them, and potentially creating a housing fund with PILOT payments to house students and faculty. As a not-for-profit, GBH is a PILOT program participant.