From 1965 through 1970, the South experienced a net migration loss -- the number of people who moved into the region compared to the number of people who moved out -- of more than 287, 000 African-Americans.

CNN: Family roots lure many African-Americans back to South

This migration likely caused a significant loss of revenue for debate organizers.

FORBES: Connect

"We think the continued discussions between our two countries on migration matters are important to prevent the needless loss of life at sea and important for ensuring the safe and legal orderly migration that's called for under the accords, " he said.

CNN: graphic

In 2006, the city had a net loss of 153, 828 residents through domestic out-migration, compared to a decline of 141, 047 in 1993, with every borough except Brooklyn experiencing a higher number of out-migrants in 2006.

FORBES: New Geographer

Science plays an important role in our response to global issues such as climate change, the hydrological cycle, biodiversity loss, natural hazards and human-induced disasters, population growth, land-use change, migration and urbanisation.

UNESCO: UK National Commission for UNESCO :: Environmental Science