Surface temperature biological control

The surface temperature and the presence of liquid water on Earth are today consequences of the atmospheric thermal control and filtering of light that is exerted by an anomalous, dominantly biogenic, atmosphere. The uniformitarian argument would thus be the present is the key to the past, hence in the past the stability of liquid water on Earth was, as today, biologically maintained - life sustains the oceans . To this argument could come the further addendum liquid water enables plate tectonics to function, subduction to operate, and andesite volcanoes to erupt . Hence if water is sustained by life, then plate tectonics and the maintenance of continents are sustained by life. But this is only unsupported conjecture. As an alternative hypothesis it... 

Fig. 14-6 Profiles of potential temperature and phosphate at 21 29 N, 122 15 W in the Pacific Ocean and a schematic representation of the oceanic processes controlling the P distribution. The dominant processes shown are (1) upwelling of nutrient-rich waters, (2) biological productivity and the sinking of biogenic particles, (3) regeneration of P by the decomposition of organic matter within the water column and surface sediments, (4) decomposition of particles below the main thermocline, (5) slow exchange between surface and deep waters, and (6) incorporation of P into the bottom sediments.

In Chapter 1, we have stressed the importance of a temperature of 300 K at the Earth s surface for the chemistry we observe here. A temperature of around 300 K is essential in two respects water is kept as a liquid and the rate of change of organic chemicals is very slow in the absence of catalysts. The second point implies that, as we remarked above, biological change is almost invariably under the control of the catalysts. 

Temperature, humidity, precipitation, and evaporation are important factors that contribute to the oxidation of sulfide minerals. In warm and wet climates, excessive precipitation may produce persistently high water tables and extensive biological activity that may create reducing conditions in the shallow subsurface and hinder sulfide oxidation (Seal et al., 2002, 208). At the surface, high humidity and temperatures would promote the oxidation of sulfide minerals (Williams, 2001, 274). Frequent precipitation would also suppress evaporation and the formation of arsenic salt deposits (Seal et al., 2002, 208). Furthermore, precipitation and groundwater, which are controlled by climate, are the major sources of water for the production of arsenic-contaminated runoff from sulfide-bearing rock outcrops. 

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