Former Secretary of State Hillary Clinton says sustainability must be one of the nation's top priorities.
Clinton spoke Thursday in Philadelphia at a conference presented by the U.S. Green Building Council.
Clinton is considered a possible contender for the 2016 Democratic presidential nomination.
She told the group she worked on environmental issues as first lady, U.S. Senator and the nation's top diplomat.
Without naming the culprits, she also criticized the nation's political atmosphere, saying "we have to overcome the divisiveness that has marked our political life and is tearing at the fabric of our society."
Philadelphia Mayor Michael Nutter also pointed out that the city has the highest percentage of people who bike to work amongst all other major U.S. cities.
The mayor also discussed a number of Philadelphia's green office buildings and developments.
