  The Nieh-Yan anomaly is the anomalous breakdown of the chiral U(1) symmetry
caused by the interaction between torsion and fermions. We study this anomaly
from the point of view of torsional Landau levels. It was found that the
torsional Landau levels are gapless, while their contributions to the chiral
anomaly are canceled, except those from the lowest torsional Landau levels.
Hence, the dimension is effectively reduced from (3+1)-dimensional to
(1+1)-dimensional. We further show that the coefficient of the Nieh-Yan anomaly
is the free energy density in (1+1) dimensions. Especially, at finite
temperature, the thermal Nieh-Yan anomaly is proportional to the central
charge. The anomalous thermal Hall conductance in Weyl semimetals is then shown
to be proportional to the central charge, which is the experimental fingerprint
of the thermal Nieh-Yan anomaly.
