« probably not what they meant » – Right, he implied Earth is a “living organism”, which is an additional proposition on top of expansion. (Who knows, maybe it is.) The bit about “increased gravity” could mean that Earth may have gained mass (via some as yet unknown mechanism) at some point of her history, something Carey touches upon in the video I linked.

I wonder how people can be so certain that Earth first accreted from "constructive" collisions out of some dust cloud, but then, once her "correct" size attained (in accordance with "Laws of Nature"), did not suffer any further changes in size or mass, except for infinitesimal ± due to hydrogen escaping or collecting shooting stars. After all, there is zero direct evidence for that story/theory, just as the interior of the Earth continues to be empirically unknown to us beyond a depth of about 12 km.

What I think is that the idea of an expanding/growing Earth (“gotten drastically bigger” at some point in the not so distant geological past, a development which cannot be observed in the present) does not fit the overall science story (physics/cosmology, mass/matter/gravity) and hence is rejected despite the geological surface evidence (see Carey video).