bio·​sphere ˈbī-ə-ˌsfir How to pronounce biosphere (audio)
: the part of the world in which life can exist
: living organisms together with their environment
ˌbī-ə-ˈsfir-ik How to pronounce biosphere (audio)

Did you know?

The lithosphere is the solid surface of the earth (lith- meaning "rock"); the hydrosphere is the earth's water (hydro- means "water"), including the clouds and water vapor in the air; and the atmosphere is the earth's air (atmos- meaning "vapor"). The term biosphere can include all of these, along with the 10 million species of living things they contain. The biosphere recycles its air, water, organisms, and minerals constantly to maintain an amazingly balanced state; human beings should probably do their best to imitate it. Though the word has a new sound to it, it was first used over a hundred years ago.

Example Sentences

Recent Examples on the Web Searching for Microbes in the Clouds of Venus Like an aerial biosphere, the proposal that venusian microbes could enter a dormant state to survive harsh conditions has precedent on Earth. Kate S. Petersen, Discover Magazine, 13 Aug. 2020 Mutualisms are crucial for the function of the biosphere. Kristin Ohlson, Discover Magazine, 2 Jan. 2019 Once the biosphere goes, the biosignatures likely go with it. Adam Frank, The Atlantic, 12 Sep. 2022 Through its protective role, the ocean absorbs 25% of the CO2 humanity has released into the atmosphere and 93% of the excess heat trapped in the biosphere. Cristina Mittermeier, CNN, 2 Nov. 2022 As such, the rock must keep the flow of waste from reaching the biosphere for as long as possible—a million years in Finland’s design. Howard Lee, Ars Technica, 17 Aug. 2022 Biosignatures have no way to leave their biosphere of origin. Adam Frank, The Atlantic, 12 Sep. 2022 The article then goes on to predict the imminent collapse of our biosphere. Jonathan M. Gitlin, Ars Technica, 21 July 2022 Many are experimenting, often at the community level, trying to find their own pathways towards that balance of well-being within a healthy biosphere. Wired, 7 July 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'biosphere.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


borrowed from German Biosphäre, from bio- bio- + -sphäre -sphere

Note: Biosphäre was introduced by the Austrian geologist Eduard Suess (1831-1914) in Die Entstehung der Alpen (Vienna, 1875), p. 159.

First Known Use

1899, in the meaning defined at sense 1

Time Traveler
The first known use of biosphere was in 1899

Dictionary Entries Near biosphere

Cite this Entry

“Biosphere.” Dictionary, Merriam-Webster, Accessed 3 Feb. 2023.

Kids Definition


bio·​sphere ˈbī-ə-ˌsfi(ə)r How to pronounce biosphere (audio)
: the part of the world in which life can exist

Medical Definition


bio·​sphere ˈbī-ə-ˌsfi(ə)r How to pronounce biosphere (audio)
: the part of the world in which life can exist
: living beings together with their environment

More from Merriam-Webster on biosphere

Last Updated: - Updated example sentences
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