17 - Aumento de la temperatura del agua
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The ocean is warming by only about a tenth of a degree at the surface and even less under water. Why so little when it absorbs 91% of the excess energy on Earth? This is because it is much larger than the atmosphere and it has a much greater calorific capacity. To measure this, you need to remember that the ocean covers 71% of the Earth's surface and that it has a depth of 4000 m on average. The atmosphere extends over a greater height, but if brought back to the same density as water, it would only be 10 m thick. (That's why we gain one atmosphere of pressure every 10 m when we dive.) Water expands very little. How can warming the ocean by a tenth of a degree result in a rise in the water level? A first answer is that the ocean is 4000 m deep on average, so a very small expansion is enough to amount to a few centimetres.
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El nivel del mar ha aumentado una media de 20 cm desde 1900. Entre 1971 y 2018, alrededor de la mitad del aumento del nivel del mar se debió a la expansión térmica de los océanos (50,4%). El deshielo de los glaciares es el segundo contribuyente con un 22,2%, seguido por el deshielo de Groenlandia (12,6%), el deshielo de la Antártida (7,1%). Aunque el deshielo de los glaciares contribuyen significativamente al aumento actual del nivel del mar, su deshielo total sólo elevaría los niveles de agua en 0,3 m, mientras que Groenlandia y la Antártida tienen el potencial de aumentar los niveles de agua en 7 m y 58 m respectivamente.
FUENTES: AR6 WG1 Box TS.4 p45 // AR6 WG1 Cross-Chapter 9.1, Figura 1: contribución al aumento de los niveles de agua p1308 (p1291) // AR6 WG1 Box TS.4, Figura 1: escenarios de aumento de agua p46 (p78)
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The increase of water temperature is not linked to ocean acidification, at least for the time being. In the long term (over several centuries), as it heats up, the water will lose its capacity to dissolve atmospheric CO2 and will become less efficient as a carbon sink. So the increase in water temperature will inhibit, to some extent, ocean acidification.