The world’s population is expected to reach seven billion on Monday, October 31, 2011. All this week The Takeaway looks at population growth and what it means for natural resources and the planet. High population growth has long concerned politicians and policymakers. The Earth’s population first reached 1 billion in 1805, around the midpoint of the industrial revolution. From 1805 it took 123 years for the world’s population to reach 2 billion. By contrast, it is estimated that it will only take 15 years until there are 8 million humans living on Earth. Matthew Connelly, author of “Fatal Misconception: The Struggle to Control World Population” and professor of history at Columbia University, has traced the history of family planning, and the often-deadly mistakes policymakers have made in the name of population control.