Is it true that if the temperature of the oceans warms, disregarding the melting ice, the sea level will rise (by how much?) just from the expansion of the molecules of the water?

Answer

There is still often a misunderstanding that the sea level rise is only due to the melting of ice at the poles. This is incorrect, on the one hand because no sea level rise can be expected from the melting sea ice. After all, ice takes up more volume than water [denk aan een volledig gevulde fles water die je in de diepvriezer plaatst!], and so the melting of this sea ice will not increase its volume. Of course, this does happen when ice that is on land melts, and when it melts, it runs to the oceans.

It is generally assumed that about half of the observed and expected sea level rise is due to the melting of this (land) ice. The other half is solely due to the expansion of water at a higher temperature, due to the stronger vibration of the molecules. In concrete terms, this means that of the currently observed sea level rise in our area of ​​approx. 15-20 cm over 85 years, half can be attributed to melting ice in polar regions, and the other half to this expansion of water.