 The <unk> Glacier in Switzerland has had one of the longest periods of scientific study with yearly measurements of the glacier 's length commencing in 1878 . The overall retreat from 1878 to 1998 has been 2 km ( 1 @.@ 2 mi ) with a mean annual retreat rate of approximately 17 m ( 56 ft ) per year . This long @-@ term average was markedly surpassed in recent years with the glacier receding 30 m ( 98 ft ) per year during the period between 1999 – 2005 . Similarly , of the glaciers in the Italian Alps , only about a third were in retreat in 1980 , while by 1999 , 89 % of these glaciers were retreating . In 2005 , the Italian Glacier Commission found that 123 glaciers in Lombardy were retreating . A random study of the <unk> Glacier in the Italian Alps indicated that the rate of retreat from 2002 to 2006 was much higher than in the preceding 35 years . To study glaciers located in the alpine regions of Lombardy , researchers compared a series of aerial and ground images taken from the 1950s through the early 21st century and deduced that between the years 1954 @-@ 2003 the mostly smaller glaciers found there lost more than half of their area . Repeat photography of glaciers in the Alps indicates that there as been significant retreat since studies commenced . 
