Teetering peaks and StP

[Impulze9]

If my opponent has a 1/1 creature and then he puts down Teetering Peaks, can I StP his creature before the +2/+0 effect from Teetering Peaks? Will my opponent gain 1 life or 3 life?

[Tammit67]

Before any spell or ability resolves, each player gets a chance to respond in turn order, starting with the active player (provided they wish to retain priority). You can swords the creature before or after it is pumped.

Where your confusion may lie is that a land is giving the buff. You cannot respond to the land coming into play, just the trigger from it. For instance, if the creature's power was based on the number of lands in play, it already counts the new land in play before anyone can do anything else, but before that (teetering peaks) trigger happens