Former Assistant Secretary for Policy in the U.S. Department of Energy Sue Tierney was scheduled to speak in Louisville tonight at 6:30, but bad weather on the east coast has forced a cancellation.I spoke with Tierney last weekabout sustainable energy, as well as coal’s future in the United States’ energy mix and differences between Chinese and American energy policies.The talk is sponsored by the World Affairs Council, and the group plans to reschedule Tierney’s talk as soon as possible.