ΔE 15.8, loose: different enough that you should pick on purpose. Emerald Scream is noticeably lighter, cooler than Guardian Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Emerald Scream is noticeably lighter, cooler than Guardian Green.
The same difference applies the other way round: Guardian Green is noticeably darker, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Guardian Green on the colour wheel See Emerald Scream on the colour wheel
All matches: Guardian Green equivalents · Emerald Scream equivalents