Gore, in Phila., issues a challenge on climate change

During a daylong seminar today at the World Affairs Council of Philadelphia, former Vice president Al Gore finished an hour-long talk by issuing a challenge to the 500 attendees and students in the room "for each of you to become a part of the solution."

In a statistics-laden keynote address, he outlined the track of climate change and the threat to national security, particularly given that the Mideast drives the price of oil.

Gore said that while the job would be difficult, the nation - and the world - have the tools now that they need to address climate change, "with the possible exception of political will."

Out in the hall, signed copies of his new book, "Our Choice," released earlier this week by Rodale Books of Emmaus, were stacked and ready for sale.

"We can build a consensus," he said. "And we must. Because not too many years from now, the next generation will look back. And depending on what the world looks like at that point, they will ask either why this generation stood back and did nothing, or how they mustered the moral courage to solve climate change."