In the last episode of LOST, Locke finds out from Dr. Shepherd that the only way to save it is to move the island. I think they would probably attempt this by altering the electromagnetic field surrounding the island- we've seen how the helicopter faces a reasonably serious challenge just trying to find the island due to some kind of weird spacetime fluctuation.
Could they be thinking about something even more exotic, like actually moving the physical isl;and fgrom pone place to another? Here's the Popular Mechanics story, Is Lost’s Island Electromagnetic Enough to Move Itself Through Space? Time-Travel Expert Says It’s Not Impossible.