Detecting biomarkers on faraway planets

(Phys.org) —On Earth, life leaves telltale signals in the atmosphere. Photosynthesis is ultimately responsible for the high oxygen levels and the thick ozone layer. Microbes emit methane and nitrous oxide into the atmosphere, ...

Mysterious source of ozone-depleting chemical baffles NASA

A chemical used in dry cleaning and fire extinguishers may have been phased out in recent years but NASA said Wednesday that carbon tetrachloride (CCl4) is still being spewed into the atmosphere from an unknown source.

Greenhouse gases to overpower ozone hole

(PhysOrg.com) -- One set of human-created gases is starting to relinquish its hold on Antarctic climate as another group of emissions produced by human activity is starting to take hold, according to a paper in Nature Geoscience, ...

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