One of Pope Francis’ most vocal supporters since his election three days ago has been Leonardo Boff, one of the founders of liberation theology, a man silenced by the Vatican in 1985 because of criticism of the church in his book The Church, Charisma and Power. 
Since 1993 he has been a Professor at the State University of Rio de Janeiro where he is now Emeritus Professor of Ethics, Philosophy of Religion and Ecology.
His more recent writings have sought to integrate ecology into liberation theology. His book, Cry of the Earth, Cry of the Poor , is seen as a synthesis of deep ecology thinking with a radical social critique. One chapter celebrates St. Francis of Assisi  as the paradigm of "the new covenant of the heart with all things", which is Boff's answer to the world's twin crises of poverty and ecological destruction.
Here’s some of what Boff has written  about Pope Francis:
Francis isn't a name; it's a plan for a Church that is poor, simple, gospel-centered, and devoid of all power. It's a Church that walks the way together with the least and last, that creates the first communities of brothers and sisters who recite the breviary under the trees with the birds. It's an ecological Church that calls all beings those sweet words "brothers and sisters". Francis was obedient to the Church and the popes and at the same time he followed his own path with the gospel of poverty in hand. …
It's worth mentioning that he's a pope who comes from the Great South, where the poorest of humankind are and where 60 percent of Catholics live. With his experience as pastor, with a new view of things, from below, he will be able to reform the Curia, decentralize the administration, and give the Church a new and credible face.