Here's a fun science story that shows one benefit from glacial retreat: scientists gain the ability to study past plant communities. On a side note, I've been in an ice cave that looks like the one in the picture (sans the tree stumps)!
"A gravel layer about 4 to 5 feet (1.2 to 1.5 meters) high appears to have encased the trees before the glacier ultimately advanced enough to plow over them, snapping off limbs and preserving the stumps in an ice tomb."
http://www.nbcnews.com/science/still-standing-ancient-alaskan-forest-thaws-melting-glacial-tomb-4B11215106?lite&lite=obnetwork
"A gravel layer about 4 to 5 feet (1.2 to 1.5 meters) high appears to have encased the trees before the glacier ultimately advanced enough to plow over them, snapping off limbs and preserving the stumps in an ice tomb."
http://www.nbcnews.com/science/still-standing-ancient-alaskan-forest-thaws-melting-glacial-tomb-4B11215106?lite&lite=obnetwork