Geoscience: Earth’s atmosphere may return to low-levels of oxygen in one billion years
Nature Geoscience
March 2, 2021
In approximately one billion years, Earth’s oxygen-rich atmosphere will return to an oxygen-poor, methane-rich composition, according to a paper published in Nature Geoscience. This finding suggests that atmospheric oxygen is not permanent on habitable worlds, which has implications for the search for life on other Earth-like planets.
An indicator of possible planetary life is a detectable, oxygen-rich atmosphere, which suggests the existence of plants and photosynthesis. Earth’s highly oxygenated present-day atmosphere is a hallmark of its biosphere. However, the lifespan of these oxygen-based biosignatures in Earth’s atmosphere is uncertain, particularly for the distant future.
Kazumi Ozaki and Christopher Reinhard modelled Earth’s systems, including climate and biological and geological processes to examine the timescale of the atmospheric conditions on Earth. They found that Earth’s oxygen-rich atmosphere will probably persist for another one billion years before rapid deoxygenation renders the atmosphere reminiscent of early Earth before the Great Oxidation Event around 2.5 billion years ago. The authors suggest that the detection of atmospheric oxygen on Earth might only be possible for 20–30% of the planet’s lifetime. If the same is true for other planets, the authors argue, then additional biosignatures are needed in the search for extraterrestrial life.
doi:10.1038/s41561-021-00693-5
Research highlights
-
Mar 22
Astronomy: Nucleic acid precursor detected on RyuguNature Communications
-
Mar 21
Ecology: Inbreeding may hamper killer whale conservationNature Ecology & Evolution
-
Mar 21
Biology: A new taste identified in fliesNature Metabolism
-
Mar 21
Astronomy: Dark skies at risk from light and space pollutionNature Astronomy
-
Mar 21
Social sciences: Nature’s endorsement of Biden assessedNature Human Behaviour
-
Mar 17
Environmental science: Crop switching can help to achieve more sustainable agriculture in ChinaNature