At most they will undue the damage that was caused by the loss of the glacier, but this will not fix what originally caused the glacier to melt.
Perhaps it will work, but we really need to look at some sort of terraforming to fix this problem. We need to generate some carbon dumps and perhaps release something into the atmosphere to reflect sunlight back into space. There are more problems to an earth warming than just it being hotter, oceans hold less carbon when they warm meaning we may be unable to stop this once it starts.