  Context. The explosive burning that drives nova eruptions results in unique
nucleosynthesis that heavily over-produces certain isotopes relative to the
solar abundance. However, novae are often ignored when considering the chemical
evolution of our Galaxy due to their low ejecta masses. Aims. In this work, we
use previously computed synthetic nova populations and the galactic chemical
evolution code OMEGA+ to assess the impact that novae have on the evolution of
stable elemental and isotopic abundances. Methods. We combine populations of
novae computed using the binary population synthesis code binary_c with the
galactic chemical evolution code OMEGA+ and detailed, white dwarf
mass-dependent nova yields to model the nucleosynthetic contributions of novae
to the evolution of the Milky Way. We consider three different nova yield
profiles, each corresponding to a different set of nova yield calculations.
Results. Despite novae from low-mass white dwarfs (WDs) dominating nova ejecta
contributions, we find that novae occurring on massive WDs are still able to
contribute significantly to many isotopes, particularly those with high mass
numbers. We find that novae can produce up to 35% of the Galactic 13C and 15N
mass by the time the model Galaxy reaches [Fe/H] = 0, and earlier in the
evolution of the Galaxy (between [Fe/H] = -2 and -1) novae may have been the
dominant source of 15N. Predictions for [13C/Fe], [15N/Fe], 12C/13C, and
14N/15N abundances ratios vary by up to 0.2 dex at [Fe/H] = 0 and by up to 0.7
dex in [15N/Fe] and 14N/15N between [Fe/H] = -2 and -1 (corresponding
approximately to Galactic ages of 170 Myr and 1 Gyr in our model). The Galactic
evolution of other stable isotopes (excluding Li) is not noticeably affected by
including novae.
