Figure 1: Schematic representation of the temperature changes during the pre-Holocene and the current Holocene periods according to the water-based heat management applied in the distant past [9-10].
In this work, we wanted to test the idea that, while the data may be questionable, the trends are sufficient to show that the radiative energy, which is balanced in climatology, is unbalanced once the absorbed infrared radiation part of the solar irradiance is turned to heat. The method is based on an estimate of the thermal energy required to melt the amount of ice that caused sea levels to rise during the last deglaciation period. To compare the evolution of the thermal imbalance during deglaciation until recent decades, the thermal energy required to cause a 120 m rise in ocean level was compared with the thermal energy during the Holocene and that required to cause the loss of 28,000 Gt of ice reported for the period 1994-2017, a multi-year period chosen to mitigate the effect of annual fluctuations [15]. Data were discussed in terms of anthropogenic heat releases evolution and the future of global climate change that will unavoidably leads to the next glaciation.
II Method and Results
II.1 Volume of water generated by ice melt during the last deglaciation
The surface area of oceans is about 361 x 106 km2 or 3.61 x 1016 dm2 (S1 in Fig. 2) [16]. The decrease of this surface was proposed to be 7 % to 9% when going from 0 to the -200 m level in the water above the average submerged shelf. The slope being greater close to the coastline [17], the variation of area between 0 and - 120 m was taken as 4.5 %. The surface at - 120 m was thus approximately 3.46 x 1016 dm2 (S2). To determine the volume of liquid water generated during deglaciation, an equivalent cylinder 1200 dm high with a circular surface of 3.53 x 1016 dm2 [(S1 + S2)/2] at - 600 dm was used (Fig. 2). The corresponding volume of water involved in the deglaciation process was thus about 4.24 x 1019 dm3 coming from about 4.24 x 1019 kg of melted ice between the maximum of glaciation and today. To melt this quantity of ice, approximately 1.4141 x 1025 J or 14,141 ZJ were required according to the 333,55 kJ/kg specific heat of melting.