abstract: Let (M,g) be a complete, connected, non-compact Riemannian three-manifold that is Ricci-pinched. In this talk, I will present a new proof based on inverse mean curvature flow that (M,g) is either flat or has sub-quadratic volume growth. As a consequence, we obtain a new proof of a conjecture of R. Hamilton recently proven by A. Deruelle, F. Schulze, and M. Simon using Ricci flow. This is joint work with Gerhard Huisken.