What is the greenhouse effect?

• Earth’s atmosphere is composed of an assortment of gases, some of which trap heat. These gases, including carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) water vapor (H₂O), ozone (O₃), and more, are referred to as greenhouse gases.
• Greenhouse gases help insulate the planet, capturing heat from incoming solar radiation. This natural process is known as the greenhouse effect. The greenhouse effect plays a major role in maintaining a stable temperature and climate. To illustrate, if all carbon dioxide was removed from the atmosphere, the average global temperature would fall by 59°F (33°C).

How is it related to climate?

• Under the natural greenhouse effect, some heat from the sun is allowed to escape the atmosphere and radiate into space (image below – left). However, anthropogenic activity, mainly the burning of fossil fuels, is releasing large amounts of greenhouse gases into the atmosphere. With a higher concentration of greenhouse gases, more heat is being absorbed, causing the planet’s surface to warm (image below – right). The anthropogenic use of fossil fuels has caused the planet to warm on average by 2.1°F (1.2°C) in comparison to pre-industrial temperatures.

Diagram demonstrating the greenhouse effect, the process of heat-trapping gases absorbing radiation from the sun and keeping the Earth’s surface and atmosphere warm (from Lai, 2021). On the left, is a model of the natural greenhouse effect, and on the right is a model of the human-enhanced greenhouse effect. Burning fossil fuels releases carbon emissions into the atmosphere, amplifying the greenhouse effect and causing the planet’s surface to get hotter.

• • Burning fossil fuels is not the only cause of global warming, although it is the primary contributor to carbon dioxide emissions. Land use changes and agricultural practices have contributed to the release of methane and nitrous oxide. Concentrations of these greenhouse gases have increased exponentially since the 18th and 19th centuries (image below), when fossil fuels became the dominant energy source for transportation, industry, electricity, and housing.

Graph depicting the change in three greenhouse gas concentrations in Earth’s atmosphere: carbon dioxide, methane, and nitrous oxide, from the years 0 to 2005 (from Lai, 2021). All three concentrations have been increasing since the 18th century, when fossil fuels became a dominant energy source. For current trends and values please see: https://gml.noaa.gov/ccgg/trends/.

References and additional resources

• EPA. “Sources of Greenhouse Gas Emissions.” Environmental Protection Agency. May 2024. https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions.
• “How Data Science Can Help Fight Climate Change.” Datascienceprograms.com. https://datascienceprograms.com/learn/how-data-science-can-help-fight-climate-change/.
• Lai, S. “Why Is The World Warming: An Introduction to Climate Change and Impact of Food.” What’s Up in Science? March 2021. https://sites.northwestern.edu/scienheal/2021/03/13/why-is-the-world-warming-an-introduction-to-climate-change-and-impact-of-food/.
• NASA. “Global Temperature.” The National Aeronautics and Space Administration. 2023. https://climate.nasa.gov/vital-signs/global-temperature/?intent=121.
• NASA. “What is the greenhouse effect?” The National Aeronautics and Space Administration. n.d. https://science.nasa.gov/climate-change/faq/what-is-the-greenhouse-effect/.
• NOAA. “Trends in CO2, CH4, N2O, SF6.” NOAA: Global Monitoring Laboratory. May 2024. https://gml.noaa.gov/ccgg/trends/.

How to cite this page

Greenhouse Effect. (2024, September 20). Climate in Global Cultures and Histories: Promoting Climate Literacy Across Disciplines. Retrieved Month Date, Year, from https://www.science.smith.edu/climatelit/greenhouse-effect/.