Seven Billion!

There was a really interesting op-ed piece published in The NY Times about ten days ago.  It was written by Joel E. Cohen, a mathematical biologist who heads the Laboratory of Populations at Rockefeller University and Columbia University.  The piece was titled, “Seven Billion.” 

Here are some of the really interesting numbers.

The UN estimates that our world population reached seven billion at the end of October.

Our world population has doubled in the past 50 years.  We had three billion in 1959, four billion in 1974, five billion in 1987 and six billion in 1998.

 The UN anticipates 8 billion people by 2025, 9 billion by 2043 and 10 billion by 2083.  India will have more people than China shortly after 2020.  Before 2040, sub-Saharan Africa will have more people than India.

 In 1950, there were nearly three times as many Europeans as sub-Saharan Africans.  By 2010, there were 16% more sub-Saharan Africans than Europeans.  By 2100, there will be nearly five sub-Saharan Africans for every European.

 Life expectancy is now 70.  The average number of children per woman fell worldwide to 2.5.  It was five in 1950.  The world’s population is growing at 1.1% per year, half the peak rate in the 1960s.

 In 1950, for each person 65 and older, there were more than six children under 15.  By 2070, elderly people will outnumber children under 15 and there will be only three people of working age (15 to 64) for every two people under 15 or 65 and older.  We will have intense pressure to extend the working age beyond 65.

 Nearly half the world lives on $2 per day or less.  In China, the figure is 36%; in India it’s 76%.

 Approximately 850 million to 925 million people experience food insecurity or chronic undernourishment.  In much of Africa and South Asia, more than half the children are stunted (low height for their age) as a result of chronic hunger.

 The world produced 2.3 billion metric tons of cereal grains in 2009-10.  This is enough calories to sustain nine to eleven billion people.  BUT…only 46% of the grain went into human mouths.  Domestic animals got 34% of the crop and 19% went to industrial uses like biofuels, starches and plastics.

 Human demands on the earth have grown enormously.  (Unfortunately, the atmosphere, the oceans and the continents have stayed the same size.)  Already, more than a billion people live without an adequate, renewable supply of fresh water.

About two-thirds of freshwater is used for agriculture.

We’re going to see huge shifts in the geopolitical balance of numbers, further declines in the number of children per woman, smaller but more numerous households, an increasingly elderly population, and growing and more numerous cities.

 Growth in households can be even more important than pure population growth.  Each household has energy demands.