Additionally, changes in sea ice levels associated with global warming have made it difficult for the hunt to carry on as smoothly as before. (treehugger.com)
The section of ice levels prove particularly difficult, because if you move to quickly you will find yourself sliding off the edge very quickly. (ticgn.com)
According to the center, global sea ice levels at the end of 2008 were «near or slightly lower than» those of 1979. (washingtonpost.com)