THE SOLUTION TO Weekly Challenge 2: People People Everywhere

 Posted by DrJeff on June 9th, 2009

 Copyright 2009  |  About this blog


Read Original Challenge HERE.


This post is a solution to a Dr. Jeff’s Weekly Challenge.


Have you figured out how many new human beings will be on the planet a year from now? It was Weekly Challenge 2 that I posted last week. (Actually one week has already gone by.) I hope you’ve not been staring endlessly at the World Population Clock.


But if you haven’t yet read Weekly Challenge 2, DON’T LOOK AT THE SOLUTION HERE JUST YET! First read Weekly Challenge 2, or I’ll deduct your existence from the World Population Clock (like that will make a difference.)


A word from our sponsor—

What Can I do with a Humongous Sheet of Xerox Paper?

Weekly Challenge 3 to be posted Monday, June 15, 2009


And now the answer—

How many new human beings will be on the planet a year from now? In just one year, will the increase in world population be the equivalent of a new big town? Or maybe a new medium-sized city? How about a large city?


And think about this—

What resources will these new folks need, and where will they get them?


The answer:

All you need to do is use the World Population Clock to figure out how much the world population increases in a known period of time, e.g., over the course of a few hours or days. That gives you the rate at which the population increases. Wait. I hear a question from Cleveland. Yes the Clock records the net increase in population, which reflects the difference between new births and deaths.

Here’s how I did it. Last night (June 8, 2009) I recorded the population at 10:30 pm EDT. This morning I recorded the population at 6:02 am EDT. That’s a span of 7 hours 32 minutes, or 452 minutes. My results:


10:30 pm June 8:     6,785,315,076  humans

6:02   am June 9:     6,785,382,952


That’s 2.5 people per second! Try recording this increase in population by counting it out 2.5 people per second, and see how far you get. You’re doing fine if you’ve counted to 150 in a minute, and 9,000 in an hour. See if you can keep it up for a day, a week, a month, a year. Don’t stop, don’t sleep, don’t eat, or you’ll miss all the new people coming aboard on spaceship Earth.

2.5 new people per second is the same as—

9,000 in 1 hour

216,000 in 1 day

1.5 MILLION in 1 week

6.6 MILLION in 1 month  AND

78,900,000 in 1 YEAR!

That’s a bit larger than the population of a new big town, or a medium sized city, or a large city in 1 year.

I’ve come up with some interesting ways to look at this using tables for the population of the world’s largest cities, the population of countries, and the population of U.S. states. Here are some statistics I’ll use—


Most populous city on Earth: Mumbai, India  13,922,000

Two most populous U.S. cities:

New York City (ranks 13th worldwide)  8,310,000

Los Angeles (ranks 47th worldwide)  3,849,000

Most Populous U.S. States

California  36,756,666

Texas  24,326,974

New York  19,490,297

Population of Countries

U.S. (ranks 3rd worldwide)  306,625,000

Germany (ranks 14th worldwide)  82,062,000

Egypt (ranks 16th worldwide)  76,753,000

Turkey (ranks 17th worldwide)  71,517,100

France (ranks 20th worldwide)  65,073

With this information, the increase in human population can be thought of as:

A new New York City every 38 days

A new Los Angeles every 18 days

A new Mumbai every 2 months

Every year, an increase in human population by roughly the current population of California, Texas, and New York COMBINED.

Every year, an increase in human population by more than the current population of Egypt, or Turkey, or France, or by almost the population of Germany. Think about that—more than a new France every year.

Finally, how long would it take for the world population to increase by an amount equal to the current population of the U.S.—the third most populous nation on the planet? Just 3.9 years—about the time it takes to put your child through college. They start as a freshman, learn about the world, graduate in 4 years, and enter a global job market that’s increased by the entire population of the U.S. while they were in class.


A parting thought

Where are all the resources needed to support these new people—water, food, shelter, energy, transportation, infrastructure  for waste management—going to come from?  And at a time when global warming is reducing fresh water supplies, and impacting agriculture through changes in regional climates. And at a time when it is imperative that the world rapidly convert to non-fossil fuel energy sources to dramatically reduce greenhouse gas emission—if our children and their children are to inherit a livable planet.


Teachers and parents

Help your class or children use the World Population Clock to figure out the rate at which the human population is growing.


Then have them research the population of their town, their state, and countries of interest. Ask them to figure out how long it would take for the population of Earth to increase by those amounts.



Have your class research a particular country, determining  the current population, the expected population growth over the next 10 years, and the challenges that country faces from limitations on resources and services resulting from global warming and the need to address it. Then hold a mock meeting of the Prime Minister’s or President’s Cabinet, with ministers of agriculture, transportation, housing, energy, health, defense, and any others that are relevant. Have the Prime Minister or President ask his/her Cabinet to lay out the near-term challenges they face, and discuss and debate solutions. Have them compare their solutions to what’s actually being debated and proposed across the world.


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2 Responses to “THE SOLUTION TO Weekly Challenge 2: People People Everywhere”

  1. k Says:
    December 2nd, 2009 at 11:25 pm

    Does this clock, from which you start your counting, and is the basis for your answer, take into account the death rates of people too, to provide the corrected net-growth? We know there is a net rise, but it’s a combination of new births combined with a death rate as well, w/ exclusion of ‘natural disaster’ issues that might provide small deltas to the calculation but are hard to model.

  2. DrJeff Says:
    December 2nd, 2009 at 11:47 pm

    Yes, the U.S. Census Bureau WorldPOPClock takes into account both birth and death rates. See: