CA Gov. Jerry Brown talks climate change at the Vatican

The governor of California, Jerry Brown, speaks during the second day of an international summit of Mayors on "Modern Slavery and Climate Change" on July 21, 2015 at the Vatican. Mayors from around the world have signed a declaration with Pope Francis stating that man-made climate change is real and humanity has a moral imperative to take action. At a two-day summit in the Vatican aimed at spurring efforts to fight global warming following the pope's environment encyclical denouncing the exploitation of the poor and the earth's resources, over 60 mayors pledged to do their part. AFP PHOTO / TIZIANA FABI (Photo credit should read TIZIANA FABI/AFP/Getty Images)

California Governor Jerry Brown has been at the Vatican this week. He's part of a group of leaders convening in Rome to discuss climate change and modern slavery.

This symposium comes a month after Pope Francis released a directive on the environment, urging politicians to take strong action.

The topic is near and dear to Brown. In an address to the gathering yesterday, Brown said:

"We have to take measures against an uncertain future, which may well be something no one ever wants. We are talking about extinction. We're talking about climate regimes that have not been seen for tens of millions of years. We're not there yet, but we're on our way."

Sacramento Bee reporter

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joins Take Two for t he latest on the Governor's visit. And Father Michael Russo, professor at St. Mary's College of California, and an expert on the intersection of the Catholic Church and American politics, joins as well.

To hear the full interview with David Siders and Father Mike Russo, click the link above.