The regulation of the air: a hypothesis

E. G. Nisbet, R. E. R. Nisbet, C.M.R. Fowler

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We propose the hypothesis that natural selec- tion, acting on the specificity or preference for CO2 over O2 of the enzyme rubisco (ribulose-1,5-bisphosphate car- boxylase/oxygenase), has controlled the CO2:O2 ratio of the atmosphere since the evolution of photosynthesis and has also sustained the Earth’s greenhouse-set surface tempera- ture. Rubisco works in partnership with the nitrogen-fixing enzyme nitrogenase to control atmospheric pressure. To- gether, these two enzymes control global surface temperature and indirectly the pH and oxygenation of the ocean. Thus, the co-evolution of these two enzymes may have produced clement conditions on the Earth’s surface, allowing life to be sustained.
Original languageEnglish
Pages (from-to)87-96
Number of pages10
JournalSolid Earth
Issue number1
Publication statusPublished - 12 Mar 2012

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