Why geothermal spring has low ph, or high concentration of H+? I guess the internal part of the earth has high concentration of H, as H is the most abundant element in the universe. When the earth was young, the surface of the earth has high concentration of H. Water is highly acidic. Air is full of hydrogen and its compounds, such as CH4. 

Why there is little hydrogen on the surface of the earth today? The earth is exposed to sunlight, whose energy splits molecules. When molecules containing hydrogen ions are split, hydrogen, with low density, rise up in the atmosphere. Over time, more and more hydrogen escaped the earth. Today, there is much less hydrogen on the surface of the earth than billions of years ago. When hydrogen ions left the water, they are replaced by sodium, potassium ions and other ions. Overtime, sea water turns from acidic into alkaline. 

When photosynthetic bacteria spit out oxygen as a byproduct, the escape of hydrogen from the earth slowed down greatly. Oxygen reacts with hydrogen to form water, which is heavy and falls back to the earth again. But the rise of hydrogen ions still forms a great electric potential from the sea water to upper atmosphere. Sea water is alkaline, which is electron donating. Oxygen is electron absorbing. So there is an electric potential between sea water and air from negative to positive. In the atmosphere, higher up has more hydrogen ions. Higher in the space, higher the electric potential. So the whole earth is a gigantic battery.

How does this gigantic battery influence other aspects of the earth? This gigantic electric field is moving along the earth. Moving electric field generates magnetic field. Does the earth’s magnetic field have anything to do with this electric field?

This gigantic electric field also produces nitrogen nutrients for plants. Lightenings are short circuits of the gigantic battery. Lightening generate chemical reactions, turning largely inert nitrogen gas into nitrogen compounds that can be absorbed  by plants. 

Does this gigantic electric field affect life in other ways? My guess is yes. But I don’t know any specific examples.