How Are Atmospheric Gases Measured?

Written By Teacher: Teresa Pettitt-Kenney

Hi there! My name is Teresa and I just finished my Bachelor's degree in Environmental Science and am excited to pursue environmental education in the future! I am extremely passionate about climate change, equitable climate action, and how education can work to address these issues. 

Exploring the gases that make up our atmosphere and which are leading to global warming can be a great way to engage students in relevant applications of chemistry and other sciences. Explore the ways that scientists investigate atmospheric gases and share your findings with your students as you explore topics like greenhouse gases and modeling the atmosphere. You can utilize engaging lessons, like Becoming Greenhouse Gases which explores greenhouse gas properties through games and discussions! Or, gain a hands-on understanding through experiments and data analysis with in-depth lessons like, Modeling the Earth's Atmosphere.

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.

Scientists regularly measure the gases that make up our atmosphere. They need this data not only to model and predict climate change, but also to track substances that contribute to pollution and other air quality issues. So how do researchers get this information?

The main way scientists measure greenhouse gases in the atmosphere is spectroscopy, says Jesse Kroll, an MIT professor of chemical engineering and civil engineering who specializes in atmospheric composition. A tried-and-true technique in many branches of science, spectroscopy involves shining electromagnetic radiation—which might be visible light, infrared or ultraviolet light, or other types of radiation like x-rays or microwaves—through a sample and studying the effects.

This works because all atoms and molecules absorb and emit light at particular wavelengths. These absorption patterns can be used as a kind of chemical fingerprint: by measuring how much radiation a sample absorbs, and at what particular wavelength, scientists can determine which substances are present and in what amounts.