Let M be a Riemannian n-manifold with a metric such that the manifold is Ahlfors-regular. We also assume either non-negative Ricci curvature, or that the Ricci curvature is bounded from below together with a bound on the gradient of the heat kernel. We characterize BMO-functions u : M → R by a Carleson measure condition of their σ-harmonic extension U : M × (0, ∞) → R. We make crucial use of a T (b) theorem proved by Hofmann, Mitrea, Mitrea, and Morris.As an application we show that the famous theorem of Coifman-Lions-Meyer-Semmes holds in this class of manifolds: Jacobians of W 1,n -maps from M to R n can be estimated against BMOfunctions, which now follows from the arguments for commutators recently proposed by Lenzmann and the second-named author using only harmonic extensions, integration by parts, and trace space characterizations.