  Double Weyl nodes are topologically protected band crossing points which
carry chiral charge $\pm2$. They are stabilized by $C_4$ point group symmetry
and are predicted to occur in $\mathrm{SrSi_2}$ or $\mathrm{HgCr_{2}Se_{4}}$.
We study their fate in the presence of quenched disorder by numerical transport
calculations and scaling arguments. We find that a double Weyl node is unstable
in a disordered environment and splits into a pair of emergent simple Weyl
nodes which carry equal chiral charge of $\pm1$. This pair of simple Weyl nodes
is robust to disorder up to a certain critical disorder strength, in complete
analogy to their `elementary' counterparts.
