Earth human population has now exceeded 7 billion. How long did it take for the world to add each billion? What improvements in health and science helped population growth? And how long do demographers think it will take to reach 8 billion, and 9 billion? This video from the Population Reference Bureau, best source we know for population data and insights, helps you visualize the answers.
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.