Figure 2: Schematic representation of the machinery that manages residual solar heat energy through water phase exchanges.
In this scheme, the Sun (1) heats the whole environment as everybody feels it under sunshine (2 and 3). Natural greenhouse effect is included in (2’). Humid air ascension and atmosphere turbulences dispatch and tend to average local imbalanced heat and raise it to the multilayered atmosphere in contact with the very cold intersidereal medium on one side, and with ground, ice and surface water on the other side. It is worth noting that in contrast to humid air, the dense CO2 tends to go down. The supply of geothermal heat is generally considered negligible as many other heat sources on Earth are, including the combustion of fossil fuels ((Zhang & Caldeira, 2015) and electricity-related ones. The temperatures of land surface and of oceans tend to increase but rising is unavoidably limited by heat absorption by the melting of ices (4’ and 6’) over the whole globe and also by the process of evaporation (evaporator) that cools ocean and surface liquid water (the refrigerant) and transfers the corresponding heat to the atmosphere as warm vapor (4). The air enriched in warm vapor being less dense than dry air, it rises up to a zone cold enough to condense the vapor as dispersed droplets and ice particles forming clouds from which the released heat is eliminated by radiation (7) and rains and snow (6) that close the cycle. In reality, the Sun does not heat continuously. Earth inclination and rotation lead to cyclic heating like day and night, summer and winter, North and South hemispheres, and the Sun long cycles. The process of ices melting and reformation is thus cyclic with ups and downs as in a refrigerator. If all the ice disappears inside the refrigerator, the inner temperature starts rising up to the outside one unless the thermostat restarts the cycle to reform ice. On Earth, the thermostat consists in water interphase equilibria. In hot summers, ices melt. In cold winter, ices are restored but the process is more and more imbalanced. If ice imbalance continues to grow, all ices will disappear sooner or later and warming will then be controlled by the sole right shift of evaporation ↔ vapor ↔ condensation interphases equilibria. This will occur progressively over the years with more and more clouds to form a thick cover that will tend to limit the solar input like durst particles and aerosols do. Less solar heat will lead to ices regeneration like in past glacial eras (Miller et al., 2012). The temperature control by evaporation-condensation depends on the latent heat of evaporation but it depends also on many dynamic factors that are major obstacle to quantification. Anyhow, temperature rise or not, the more heat to be dispatched over the globe, the stronger and the more frequent chaotic environmental have to be, at least qualitatively (Fig. 2), a trend already observed today (Reed et al., 2021) although temperature rise is no more than a few hundredths of a Celsius degree annually. Water cycle has been already proposed as climate factor but generally without involving ices and not in terms of quantitative water interphase equilibria.