Reprinted from Science Daily Magazine ... Source: CSIRO Australia Date Posted: Monday, July 19, 1999 Web Address: http://www.sciencedaily.com/releases/1999/07/990719033405.htm Oxygen Measurements Yield Greenhouse Clues As levels of the greenhouse gas carbon dioxide rise, concentrations of oxygen in our air have fallen.
(concentrations of oxygen in our air; have fallen; )
concentrations of oxygen in our air
have fallen