Science, Tech, Math › Science 10 Worst Greenhouse Gases Share Flipboard Email Print Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 09, 2020 A greenhouse gas is any gas that traps heat in the Earth's atmosphere rather than releasing the energy to space. If too much heat is conserved, the Earth's surface heats up, glaciers melt, and global warming occurs. But greenhouse gases aren't categorically bad, because they act as an insulating blanket keeping the planet a comfortable temperature for life. Some greenhouse gases trap heat more effectively than others. Here's a look at the 10 worst greenhouse gases. You may be thinking carbon dioxide will be the worst, but it's not. Can you guess which gas is? 01 of 10 Water Vapor Water vapor accounts for most of the greenhouse effect. Martin Deja, Getty Images The "worst" greenhouse gas is water. Are you surprised? According to the Intergovernmental Panel on Climate Change or IPCC, 36–70% of the greenhouse effect is due to water vapor in the Earth's atmosphere. One important consideration of water as a greenhouse gas is that an increase in the Earth's surface temperature increases the amount of water vapor air can hold, leading to increased warming. 02 of 10 Carbon Dioxide Carbon dioxide is only the second most important greenhouse gas. INDIGO MOLECULAR IMAGES, Getty Images While carbon dioxide is considered the greenhouse gas, it's only the second largest contributor to the greenhouse effect. The gas occurs naturally in the atmosphere, but human activity, particularly through the burning of fossil fuels, contributes to its concentration in the atmosphere. 03 of 10 Methane Cattle are a surprisingly significant producer of methane that is released into the atmosphere. HAGENS WORLD - PHOTOGRAHY, Getty Images The third worst greenhouse gas is methane. Methane comes from both natural and man-made sources. It is released by swamps and termites. Humans release methane trapped underground as a fuel, plus cattle ranching contributes to atmospheric methane. Methane contributes to ozone depletion, plus acts as a greenhouse gas. It lasts about ten years in the atmosphere before being converted mainly to carbon dioxide and water. The global warming potential of methane is rated at 72 over a 20 year time frame. It does not last as long as carbon dioxide, but has a greater impact while its active. The methane cycle is not completely understood, but the concentration of methane in the atmosphere appears to have increased 150% since 1750. 04 of 10 Nitrous Oxide Nitrous oxide or laughing gas is used for a variety of purposes, including automotive use and as a recreational drug. Matthew Micah Wright, Getty Images Nitrous oxide comes in at No. 4 on the list of worst greenhouse gases. This gas is used as an aerosol spray propellant, anesthetic and recreational drug, oxidizer for rocket fuel, and to improve engine power of automotive vehicles. It is 298 times more effective at trapping heat than carbon dioxide (over a 100 year period). 05 of 10 Ozone Ozone both protects us from solar radiation and traps it as heat. LAGUNA DESIGN, Getty Images The fifth most powerful greenhouse gas is ozone, but it isn't evenly distributed around the globe, so its effects depend on location. Ozone depletion from CFCs and fluorocarbons in the upper atmosphere allows solar radiation to leak through to the surface, with effects ranging from ice cap melting to an increased risk of skin cancer. An overabundance of ozone in the lower atmosphere, primarily from man-made sources, contributes to heating the Earth's surface. Ozone or O3 also is produced naturally, from lightning strikes in air. 06 of 10 Fluoroform or Trifluoromethane One use of fluoroform is in commercial fire suppression systems. Steven Puetzer, Getty Images Fluoroform or trifluoromethane is the most abundant hydrofluorocarbon in the atmosphere. The gas is used as a fire suppressant and etchant in silicon chip manufacture. Fluoroform is 11,700 times more potent than carbon dioxide as a greenhouse gas and lasts for 260 years in the atmosphere. 07 of 10 Hexalfuoroethane Hexafluoroethane is used in the production of semiconductors. Science Photo Library - PASIEKA, Getty Images Hexalfuoroethane is used in semiconductor manufacturing. Its heat-holding capacity is 9,200 times greater than carbon dioxide, plus this molecule persists in the atmosphere over 10,000 years. 08 of 10 Sulfur Hexafluorid By CCoil, Wikimedia Commons, (CC BY 3.0) Sulfur hexafluoride is 22,200 times more potent than carbon dioxide at capturing heat. The gas finds use as an insulator in the electronics industry. Its high density makes it useful for modeling dispersal of chemical agents in the atmosphere. It's also popular for conducting science demonstrations. If you don't mind contributing to the greenhouse effect, you can get a sample of this gas to make a boat appear to sail on air or to breathe to make your voice sound deeper. 09 of 10 Trichlorofluoromethane Refrigerants, such as trichlorofluoromethane, are notorious greenhouse gases. Alexander Nicholson, Getty Images Trichlorofluoromethane packs a double punch as a greenhouse gas. This chemical depletes the ozone layer faster than any other refrigerant, plus it holds heat 4,600 times better than carbon dioxide. When sunlight strikes trichloromethane, it breaks apart, released chlorine gas, another reactive (and toxic) molecule. 10 of 10 Perfluorotributylamine and Sulfuryl Fluoride Sulfuryl fluoride is used for termite fumigation. Wayne Eastep, Getty Images The tenth worst greenhouse gas is a tie between two newer chemicals: perfluorotributylamine and sulfuryl fluoride. Sulfuryl fluoride is an insect repellent and termite-killing fumigant. It's about 4,800 times more effective at trapping heat than carbon dioxide, but it breaks down after 36 years, so if we stop using it, the molecule won't accumulate to cause further harm. The compound is present at a low concentration level of 1.5 parts per trillion in the atmosphere. However, it's a chemical of concern because, according to the Journal of Geophysical Research, the concentration of sulfuryl fluoride in the atmosphere is increasing 5% each year. The other contender for 10th worst greenhouse gas is perfluorotributylamine or PFTBA. This chemical has been used by the electronics industry for over half a century, but it's gaining attention as a potential global warming gas because it traps heat more 7,000 times more efficiently than carbon dioxide and persists in the atmosphere for over 500 years. While the gas is present at very low amounts in the atmosphere (around 0.2 parts per trillion), the concentration is growing. PFTBA is a molecule to watch. Sources and More Information Anderson, Thomas R., Ed Hawkins, and Philip D. Jones. "Co2, the Greenhouse Effect and Global Warming: From the Pioneering Work of Arrhenius and Callendar to Today's Earth System Models." Endeavour 40.3 (2016): 178–87. Robertson, G. Philip, Eldor A. Paul, and Richard R. Harwood. "Greenhouse Gases in Intensive Agriculture: Contributions of Individual Gases to the Radiative Forcing of the Atmosphere." Science 289.5486 (2000): 1922–25. Schmidt, Gavin A., et al. "Attribution of the Present-Day Total Greenhouse Effect." Journal of Geophysical Research: Atmospheres 115.D20 (2010).