Virizion EX Emerald Slash

[Charizard3712]

Say I were to Emerald Slash and there was only one Grass Energy in my deck. The attack doesn't read 'up to 2' so would I be unable to attach the one energy?

 

[PokePop]

Pokemon uses the concept of "do as much as you can".
So attach the one energy, if you want.
You can also fail a deck search for a specific type of card, if you want.