Mayor Bill de Blasio wrapped up his trip to the Vatican on Wednesday with a keynote speech on cities and how they can sustain themselves in the face of climate change.

In his address, the mayor called on world leaders to take bold steps to fight climate change.

But he also highlighted the ways his administration adapted former mayor Michael Bloomberg's environmental plan to better address income inequality. 

"A wonderfully, environmentally sustainable city or nation in which inequality was rampant, where there was no actual economic inclusion would be considered a failure. Equally, the most prosperous, the most economically prosperous city or nation that was slowly degrading environmentally would also be considered a failure. We now have to raise both bars simultaneously," De Blasio said.

The mayor also promised to force the city's private sector to act if it doesn't do more to help the city reach its environmental goals.

NY1 has a team traveling with the mayor in Italy and will have reports throughout the day.