. >> i'm barbara meade. i am one of the owners here at politics and prose. this evening i want to welcome bill mckibben, one of the most prominent environmental activists in our community. [applauding] bill is a scholar and resident at middlebury college. he is co-founder of the on-line community, 350.org. in case you don't know, the name of the organization 350 comes from the fact that leading scientists have said that only 35 parts per million in the atmosphere is the most that any climate can tolerate. if it goes over that then things are getting very unsafe. more than 20 years ago in his book, "the end of nature," bill mckibben warned about the impact of the destructive practices that could and have led to a global warming. through 12 books in the past 20 years he has continued his witness to the earth's declining health and its atmosphere's slowing pollution. now bill mckibben new book, "eaarth". he will speak this evening he will speak about why it has an idiosyncratic spelling. a passionate incitement along with a practical vision for maintaining what