Update September 3: The webchat has ended, but you can read a transcript here.

Global population numbers are on track to reach 7 billion in 2011, just 12 years after reaching 6 billion in 1999. Even with declining fertility rates in many countries, world population is growing at a rapid rate. Virtually all of that growth is in developing countries. The Population Reference Bureau will host a Discuss Online we chat called World Population: 7 Billion on the Horizon on Sept. 3, 2009 from 10:30–11:30 a.m. (EDT).

Presenters include Carl Haub, PRB senior demographer and co-author of the new 2009 World Population Data Sheet; Mary Mederios Kent, senior demographic editor and co-author of the 2009 World Population Data Sheet; Linda Jacobsen, PRB’s vice president of Domestic Programs; and James Gribble, PRB’s vice president of International Programs.

On Aug. 12, PRB released its 2009 World Population Data Sheet. Here are some key findings:

Africa’s population has just passed 1 billion.

About half the world lives in poverty.

HIV prevalence now appears to be on the decline in Africa.

The birth rate among U.S. teenagers is twice as high as the average for all developed countries.

During the Discuss Online, four PRB demographers will answer your questions about world population growth and the factors driving it.

The 2009 World Population Data Sheet and summary report are online: http://www.prb.org/Publications/DataSheets/2009/2009wpds.aspx

Watch a webcast of the press briefing held on Aug. 12: http://www.prb.org/Journalists/Webcasts/2009/2009wpds-webcast.aspx