$k^{-3}$ term, arising from the dominant downscale enstrophy cascade, and a subdominant $k^{-5/3}$ term, arising from the hidden downscale energy cascade, which allows, in principle, a transition from the $-3$ slope to the $-5/3$ slope. In linearly dissipated two-dimensional turbulence, this transition is not expected to be realized, because an upper bound on the energy flux forces the transition scale $k_t$ to be greater than the dissipation scale $k_d$ of the enstrophy cascade. If $\Pi_E (k)$ is the energy flux from the $(0,k)$ wavenumber interval to the $(k,+\infty)$ interval and $\Pi_G (k)$ is the enstrophy flux from $(0,k)$ to $(k,+\infty)$, then this flux inequality reads $k^2 \Pi_E (k)-\Pi_G (k)<0$, for all wavenumbers $k$ not in the forcing range. The origin of this inequality is the relationship $D_E (k) = k^{-2} D_G (k)$ between the energy dissipation spectrum $D_E (k)$ and the enstrophy dissipation spectrum $D_G (k)$. Thus, with increasing wavenumber $k$, the proportion of the energy dissipation rate relative to the enstrophy dissipation rate vanishes rapidly with $k^{-2}$, and this rapid decrease is the reason why the downscale energy cascade coexisting with the downscale enstrophy cascade cannot be seen in the energy spectrum. However, the subtle point that deserves to 