Like almost all other glaciers in the Alps, and most glaciers on the globe as well, due to global warming the Gorner Glacier is a retreating glacier—and in quite a dramatic way.
Nowadays (2014), Gorner Glacier retreats about 30 metres (98 ft) every year, but with a record loss of 290 metres (950 ft) in 2008.
Since its last major expansion (in the modern era, after the last glacial period) in 1859, it lost more than 2,500 metres (8,200 ft) in distance.

In these days (c. 2015) this becomes quite obvious because the uneducated visitor usually misidentifies Gorner Glacier's main tributary as its upper part: the Grenzgletscher (English: Border Glacier) on the south side of the central, visible Monte Rosa massif.
However, the upper Gorner Glacier traditionally is to be found on the north side.
The reason is that the upper part of the Gorner Glacier is currently losing contact with its lower part and now the Grenzgletscher has become its much larger tributary.
So it is easy to mismatch the Border Glacier as the upper Gorner Glacier.

But this was not the case in earlier times, as the following comparison impressively shows (be also aware of the retreating of the Monte Rosa Glacier in the middle, the one in between Gorner and Border Glaciers):
Like almost all other glaciers in the Alps, and most glaciers on the globe as well, due to global warming the Gorner Glacier is a retreating glacier—and in quite a dramatic way. Nowadays (2014), Gorner Glacier retreats about 30 metres (98 ft) every year, but with a record loss of 290 metres (950 ft) in 2008. Since its last major expansion (in the modern era, after the last glacial period) in 1859, it lost more than 2,500 metres (8,200 ft) in distance.
In these days (c. 2015) this becomes quite obvious because the uneducated visitor usually misidentifies Gorner Glacier's main tributary as its upper part: the Grenzgletscher (English: Border Glacier) on the south side of the central, visible Monte Rosa massif. However, the upper Gorner Glacier traditionally is to be found on the north side. The reason is that the upper part of the Gorner Glacier is currently losing contact with its lower part and now the Grenzgletscher has become its much larger tributary. So it is easy to mismatch the Border Glacier as the upper Gorner Glacier.
But this was not the case in earlier times, as the following comparison impressively shows (be also aware of the retreating of the Monte Rosa Glacier in the middle, the one in between Gorner and Border Glaciers):
Gorner Glacier