Greenhouse gas
heat-trapping gas in a planet's atmosphere
Greenhouse gases (GHGs) are the gases in an atmosphere that trap heat, raising the surface temperature of astronomical bodies such as Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by greenhouse gases. Without greenhouse gases in the atmosphere, the average temperature of Earth's surface would be about −18 °C (0 °F), rather than the present average of 15 °C (59 °F). Human-induced warming has been increasing at an unprecedented rate since it has started being measured, reaching 0.27±0.1 °C per decade over 2015–2024. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 53.6±5.2 Gt CO2e per year over the last decade (2014–2023), as well as reductions in the strength of aerosol cooling.
The five most abundant greenhouse gases in Earth's atmosphere, listed in decreasing order of average global mole fraction, are: water vapor, carbon dioxide, methane, nitrous oxide, ozone. Other greenhouse gases of concern include chlorofluorocarbons (CFCs and HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons, SF6, and NF3. Water vapor causes about half of the greenhouse effect, acting in response to other gases as a climate change feedback.
Human activities since the beginning of the Industrial Revolution (around 1750) have increased carbon dioxide by over 50%, and methane levels by 150%.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Aug 17, 2026. The linked authority identifier is Q167336. The Library of Congress control number is sh90000985. None of the 1 selected statements returned an explicit reference. The first chronological checks are 2015, 2024, 2014 and 2023.
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This entry incorporates text from “Greenhouse gas” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.