Thus, N2 or its oxidized forms would have provided raw materials for an important and plentiful source of ammonia in the ancient oceans, perhaps providing oases of NH3 for the production of amino acids and nucleic acids in early life forms. Brandes and coauthors point to two important conclusions, in addition to the unexpectedly high production of ammonia. Thus, the ammonia necessary for the origins of life must have been generated after the initial formation of the Earth. The radiation output of the Sun has increased gradually over the past several billion years. During the Earth's formation, the Sun's radiant energy does not appear to have been sufficient to maintain liquid oceans unless, that is, a significant amount of a greenhouse gas was present to trap the Sun's energy and keep the planet warm.
Ammonia is one of the most efficient greenhouse gases.
If the oceans maintained a steady production of ammonia from hot vents, that ammonia would have also enriched the atmosphere through water-gas exchange at the ocean's surface, perhaps resolving the paradox. Surprisingly, this research does little to settle an ongoing debate regarding the most probable site of life's origins. The prevailing paradigm for almost half a century has been that life began near the ocean's surface, bathed in sunlight. The rival hypothesis, that life arose near deep hydrothermal vents, is now being investigated at the Geophysical Laboratory and several other labs around the world. The present work demonstrates that high concentrations of ammonia might occur near vents, possibly making them sites for some interesting pre-life chemistry.