Occupying Earth: Welcome to the 7 Billion Club!

Congratulations! You are part of a historic milestone: Planet Earth now has 7 billion travelers as it zips around the sun.

In 1800, it had a mere 1 billion. The 2 billion mark took another 130 years to reach, making it in 1930. The 3 billion milestone came in 1960, followed by 4 billion in 1974, 5 billion in 1987, and 6 billion in 1999.

Consider this: A person who is now about 80 years old has seen a worldwide population increase of over 5 billion in his or her lifetime! Someone born during the first year of the Kennedy administration in 1961 has seen the planet’s population more than double. Put another way, it took all of human history up to 1930 to reach a population level equal to the increase in population that a person born in 1987 has already experienced.

The milestone moment of 7 billion achieved on Halloween is the topic of an ongoing series this year sponsored by National Geographic. Obviously, the implications for the planet are huge and have not escaped the notice of scientists worldwide; in fact, there is even a free “7 Billion” app available now for your iPhone and iPad. It’s full of stunning graphics and facts and figures and interesting articles. Here are some of the most interesting facts associated with the historic 7 billion milestone:

• How big is 7 billion? Assuming that it would take you one second to say a number and that you never made a mistake in your counting, it would take a human being 200 years to count to 7 billion.
• How far could you travel if you took 7 billion steps? You could walk from Connecticut to California and back more than 830 times.
• Every second, five people are born and two people die somewhere on the planet, giving us a net increase in population each second of three people. Put another way, if it takes you three minutes to read this article, the population of the planet will have increased by about 175 people. If your commute to and from work takes an hour, the world’s population will have increased by about 3,500 during your trek. The net population increase for one day on the planet is approximately 84,000.
• During the first year of the Kennedy administration in 1961, the average lifespan for a human being worldwide was 53 years; in 2010, the average lifespan has surpassed 69 years — an increase exceeding 33 percent. In the United States, the average lifespan of a white citizen in 1900 was about 47 years. By 2011, the average lifespan has increased to about 80 years — a remarkable achievement. When FDR signed the Social Security Act in 1935, the average recipient was expected to live to about 69 or to collect benefits for about four years. The 11-year increase in American life expectancy has obviously put a financial burden on the largest government program in the world.
• Another startling fact concerns what are known as “megacities.” A megacity is defined as a city with a population of at least 10 million. In 1975, there were three megacities in the world: Tokyo, Mexico City, and New York City; in 2011, there are now 21 — a seven-fold increase. The implications for food, clean water, sanitation, transportation, and medical care are enormous. So profound are the effects of human population increase on the planet that some geologists have proposed a new name for our era: Anthropocene — a term coined by Nobel-winning Dutch scientist Paul Crutzen about 10 years ago.
• The National Geographic app also contains several compelling human-interest stories. Imagine, for example, living in Bangladesh, which has a population that exceeds Russia but is crammed into a country the size of Louisiana. It is “mathematically incapable of truly being alone” in this nation of 164 million people. Additionally, rising seas are shrinking the land mass for the population.
• Conversely, Brazil, surely one of the most interesting countries in the world today for lots of reasons, has managed to reduce its per capita birthrate to 1.9 and has actually begun to reduce its population of 191 million. According to National Geographic writer Nancy Gorney, women across all social classes there are determined to take control of their lives by controlling reproduction: “A fabrica esta fechada” is a sentence commonly uttered by many Brazilian women: “The factory is closed.” They have aggressively taken charge of their reproductive futures.
• During Halloween this year, most people in Connecticut were too busy trying to deal with the inconveniences to their daily routine wrought by the record-breaking October snowfall to realize that they were part of a new human population record achieved sometime that night while the kids were out trick-or-treating. Our own state has grown from a population of about 235,000 in the first census of 1790 to about 3.5 million in 2011 — a rate that is double the rate of increase in the world’s population during the same time period.
• Incidentally, according to National Geographic, the Quahog clam — one of the longest-living marine organisms there is, and one that is commonly found on the coast of southern New England — can live to well over 200 years. A Quahog born in 1790 and still alive today will have lived — you guessed it — about 7 billion seconds!