From his eulogy at National Catholic Register Online:
Passionist priest and acclaimed cultural historian Thomas Berry...was one the 20th-century's most probing thinkers on the human relationship with the natural world and its implications for religion. [snip]
Fr. Thomas Berry, described in Newsweek magazine in 1989 as "the most provocative figure among the new breed of eco-theologians," was among the first to say the earth crisis is fundamentally a spiritual crisis. His diagnosis of the negative effects of our religious views on our treatment of the planet rang true for many who were willing and able to work for a cure. Many created their own earth ministries, inspired by the work and life of Fr. Thomas Berry.
Rather than a theologian, Berry considered himself a cosmologist and "geologian," an Earth scholar.
Not always popular, certainly influential. More links to his life and writings here.
UPDATE: NY Times green columnist Andrew Revkin's thoughts here. And Nic Paton elicits quite a few comments in a post that lumps Berry in with other Emergent Christians.
"The earth crisis is fundamentally a spiritual crisis."
This should be the headline on every newspaper, magazine, TV news broadcast and website around the world. God's Truth, as spoken through Thomas Berry, and now through you. A wonderful tribute, Don!