  Carbon nanoconductors are known to have extraordinary mechanical strength and
interesting magnetic properties. Moreover, nanoconductors based on one- or
two-dimensional carbon allotropes display a very high current-carrying capacity
and ballistic transport. Here, we employ a recent, simple approach based on
density functional theory to analyze the impact of strong current on the
mechanical and magnetic properties of carbon nanoconductors. We find that the
influence of the current itself on the bond-strength of carbon in general is
remarkably low compared to e.g. typical metals. This is demonstrated for carbon
chains, carbon nanotubes, graphene and polyacetylene. We can trace this to the
strong binding and electronic bandstructure. On the other hand, we find that
the current significanly change the magnetic properties. In particular, we find
that currents in graphene zig-zag edge states quench the magnetism.
