As world leaders prepare to meet in Paris next week for the United Nations summit on climate change, mayors from cities around the world also plan to be there—including Pittsburgh mayor Bill Peduto. It’s an issue Peduto has been following for a long time, as indicated by the poster in his house from the climate summit in Rio De Janeiro in 1992.

“I thought that the solution would happen within 10 years,” Peduto says. “It’s now 2015, and I have an opportunity to be a part of it.”

LISTEN: Pittsburgh Mayor Bill Peduto Heading to Paris for Climate Talks

As global leaders negotiate a climate deal, mayors and other local-level representatives are planning their own meeting on climate change at Paris city hall. Peduto says other governments are interested in how Pittsburgh has cleaned up since its days as a dirty industrial city.

The #ClimateMayors hashtag on Twitter has been drawing attention to how much of the world population is moving to urban areas and the need for cities to be part of solutions to climate change. Cities now produce 70 percent of the world’s greenhouse gas emissions and are the most affected by global warming.

How to Talk Politics at Holiday Gatherings Without Causing a Family Feud

Talking about issues like climate change with family and friends at the holidays is supposed to be a big no-no. Mary Beth Mannarino, who teaches psychology at Chatham University in Pittsburgh, says the topic often makes us confront uncomfortable aspects of the kind of lives we’re living and can make us feel judged. But Mannarino says it is possible to broach the issue—even with those that have differing opinions— if you’re thoughtful in your approach to the conversation.

“What we find when we talk about climate change or other environmental issues is if you reach out and ask the other person about their beliefs and show a genuine interest in it and why they feel so strongly about it, then you’re meeting them where they are,” Mannarino says. “Then you can say something like—I’ve done a lot of thinking about this as well and here are some things I’ve done to educate myself about it. So meet them where they are, and then express yourself in a way that respects that they might be different.”

And if things get heated, Mannarino says to take the high road.

“Say that you’d be happy to talk about it another time, if somebody really wants to sit down and hammer out some of the differences that you have about it,” Mannarino says. “What we know from research about this is that nobody changes their mind in response to preaching, or even just giving factual information. It’s more, We’re in this together, and let’s get to know each other, and let’s kind of talk about this.