According to the United Nations Population Fund counters, Halloween will be the approximate date when the 7 billionth human will be born on to our planet (give or take a day or a month or two). Some believe this milestone is not an event to be feared but celebrated for its seeds of possibility, while others (those pesky 'population bombers') look at it as a further warning light on the planet's dashboard.
Who is right?
Photo Chrisdlugosz via flickr and Creative Commons.
The question How Many People Can The Earth Support? was taken up by biologist Joel Cohen in his book of the same name. After years of reviewing the data, Cohen's answer is...well perhaps both those views are right.
The acceleration of human population growth is astounding and a little scary. In the 1700's around 500 million people walked the planet. Fast forward to the 1800's before the number reached a billion, and to the 1930's before the two billion mark was reached.
Then, of course compound growth brought the number to six billion by the end of the century, and sometime this year, presumably around Halloween, we'll get to seven billion people.
That growth spurt isn't over - it is estimated we will reach nine billion humans by about 2045. The boom is in part due to demographics - so many more women are in child-bearing age. Conversely, though the rough population numbers keep rising and rising, birth rates are simultaneouly falling, country by country, as development happens.
Looking at environmental indicators, the Earth already seems to shoulder too much burden at the seven billion mark. As National Geographic author Robert Kunzig puts it, "Water tables are falling, soil is eroding, glaciers are melting, and fish stocks are vanishing. Close to a billion people go hungry each day."
Malthus surmised long ago than when population grew faster than food supply, war and famine would bring human numbers back into sustainable limits. But agricultural productivity has come to the rescue again and again, and population continues to be able to grow - food production has risen even since Paul Erlich wrote his pessimistic (and Malthusian) best seller The Population Bomb.
So can falling birth rates and new technology continue to eke enough food and resources out of an Earth many consider tapped out?
Lester Brown of the Earth Policy Institute believes the answer is no, and food production will soon be cramped, famine becoming more widespread.
Joel Cohen doesn't give a prescription at the end of his book for what we should do - in analyzing population numbers he found there are more or less scenarios different people put forward to deal with growing population - there are *bigger pie* types, "fewer forks" folks, and a "better manners" camp. The bigger pie types believe in technology expanding Earth's productive capacity. while fewer forks folks want to stop population growth, and the better manners group wants to just make a better world trusting all the other problems will likely drop away when we do so.
Cohen says one action that would satisfy all those groups is universal primary and secondary education - a population that is educated to secondary level world-wide would have the intellectual capacity to make the Earth more productive, control its own fertility, and demand effective, well-functioning government. Even at 7, or eventually 9 billion inhabitants.
Read more about population:
If The World's Population Lived In One City
At NYC's Density, The World Could Live In Texas
Ending Population Growth