  Using the non-commutative Kubo formula for aperiodic solids [1-3] and a
recently developed numerical implementation [4], we study the conductivity
$\sigma$ and resistivity $\rho$ tensors as functions of Fermi level and
temperature, for models of strongly disordered Chern insulators. The formalism
enabled us to converge the transport coefficients at temperatures low enough to
enter the quantum critical regime at the Chern-to-trivial insulator transition.
We find that the $\rho_{xx}$-curves at different temperatures intersect each
other at one single critical point, and that they obey a single-parameter
scaling law with an exponent close to the universally accepted value for the
unitary symmetry class. However, when compared with the established
experimental facts on the plateau-insulator transition in the Integer Quantum
Hall Effect, we find a universal critical conductance $\sigma_{xx}^c$ twice as
large, an ellipse rather than a semi-circle law, and absence of the quantized
Hall insulator phase.
