The more geology and tectonic knowledgeable here can educate me, but the whole 'sea level rise' claim is a two way street that can either be due to actual rising water, or sinking land masses.
Like most material substances, heating or cooling can cause expansion or contraction of that substance, so it would seem on a planetary scale the same thing would apply. Less solar energy, the Earth contracts, more and it expands.
Maybe that's bull doody because it's too simple, but if true you notice they never even try to conceive it, because everything must be steered to global warming.