Greta Stacy is a high school science teacher in Doha, Qatar. She has previously taught in Ecuador and the United States.
A common misconception about climate change is that because CO2 makes up such a small percentage of the atmosphere, it can’t really be contributing to global warming. This topic can also be challenging to teach because working with ppm and very large numbers can be difficult for students to visualize. This middle school math lesson on Calculating the Rate of Change of Atmospheric CO2 gives students a chance to graph the amount of CO2 in the atmosphere over time, seeing for themselves that the amount of CO2 in the atmosphere has increased dramatically in the recent past. This video gives a good introduction to the topic for older students, who could then dig into some data for extension.
Written By: MIT Environmental Solutions Initiative
The MIT Climate Change Engagement Program, a part of MIT Climate HQ, provides the public with nonpartisan, easy-to-understand, and scientifically-grounded information on climate change and its solutions.
In June 2023, the National Oceanic and Atmospheric Administration announced that measurements of carbon dioxide (CO2) at their Mauna Loa Atmospheric Baseline Observatory had reached 424 parts per million (ppm).
This means that of every one million molecules in the atmosphere, 424 are CO2. It can be hard to imagine how a chemical compound that makes up such a small fraction of the atmosphere—less than 0.05%—can be responsible for so much global warming. Yet focusing on the fraction of CO2 in the atmosphere can blind us to just how big a change this represents.
First, we are more perceptive to the effects of small fractions than you might think. Consider your daily cup of coffee. Its power to raise your alertness, energy and heart rate comes from caffeine, which, by coincidence, is present at around 400 ppm. As NASA, who made the analogy, put it: “Small amounts of powerful substances have big effects.”
