Sentences with phrase «whether oxygen concentrations»

«Until now, we haven't been able to tell whether oxygen concentrations 2.5 billion years ago were stable or not.

Because oxygen is critical to many forms of life and geochemical processes, numerous models and indirect proxies for the oxygen content in the atmosphere have been developed over the years, but there was no consensus on whether oxygen concentrations were rising, falling or flat during the past million years (and before fossil fuel burning).

Not exact matches

> The concentration of CO2 is the wrong measure for deciding whether it is «tiny», because it compares the amount of CO2 with the amounts of oxygen and nitrogen which don't absorb infra - red at normal pressures.