Assertion: gas's volume | /r/HasProperty | ppmv
Facets:
Source sentences:
text: Atmospheric CO 2 concentrations fluctuated between 275 and 290 parts per million by volume (ppmv) of dry air between 1000 ce and the late 18th century but increased to 316 ppmv by 1959 and rose to 412 ppmv in 2018.