Billions & Billions (Updated!)

What are the consequences of human population growth?

Billions & Billions (Updated!)

What are the consequences of human population growth?

Check it out! This lesson was just updated in September 2024, and we hope you love the new and improved version. If you've already prepped an earlier version, fear not, you can still find those here through Thursday December 5, 2024.

Scientists estimate that on Halloween 2011 the global population reached 7 billion. But how long did it take humanity to grow to this level, and how large should we expect our population to become?

In this lesson, students will explore how many people the Earth is adding and losing each minute, and use this to build an exponential model for human population growth. They’ll also predict what the world population will be in the future and discuss the environmental consequences of population growth and economic development.

REAL WORLD TAKEAWAYS

Since 1900, the global human population has grown exponentially.
As the human population has grown, so has the amount of carbon dioxide in the atmosphere and the sea level.
Today, the human population is growing fastest in so-called “developing” countries that are less wealthy and currently industralizing, while the population is growing less quickly in “developed” countries that are wealthier and have already industrialized. Because less wealthy countries often depend on inexpensive and more pollution-producing sources of energy (e.g. coal), their industrialization risks exacerbating climate change. Allowing them to industrializing cleanly may require support from other countries.

MATH OBJECTIVES

Given two data points, calculate the change in both absolute terms (e.g. additional people per year) and as a percent.
Discuss the appropriateness of a linear vs. exponential model for a given situation.
Create an exponential function to forecast into the future.