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Comment by muro | Hacker News Reader

Interesting also because 2018 had an unusually long winter and likely more snow than usual. I would have expected it to be the year when glaciers would get bigger for a change.

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As a long distance ice skater I know that snow has a detrimental effect on ice growth due to its insulating effect.

Moreover the spring and summer of 2018 were warm [1] and sunny [2] in Europe. The comparison picture in the article of this tiny glacier after a cold [3] and cloudy [4] spring and summer of 2006 is not a solid basis for drawing conclusions.

[1] https://www.meteoschweiz.admin.ch/product/output/climate-dat...

[2] https://www.meteoschweiz.admin.ch/product/output/climate-dat...

[3] https://www.meteoschweiz.admin.ch/product/output/climate-dat...

[4] https://www.meteoschweiz.admin.ch/product/output/climate-dat...

Ice growth on a glacier is what remains of snow over one year. I don't know proper english jargon, but glaciers usually accumulate snow from around october to june. June to october is the melting period.

Obvious: glacier growing means it accumulates more snow (that will slowly convert into solid ice) than is melting in the summer.

Exactly, there is no magic - all the ice is just snowfall compressed over time, by its own weight and melting/refreeze cycles.

This autumn has been really great for outdoors but disastrous to glaciers - extremely warm till end of october, no precipitation at all for more than a month.

Glaciers work differently from ice on a pond. They have a 'budget' which is determined by the rate at which snow accumulates on the top and the rate at which melting occurs lower down. When glaciers are stable they have net accumulation above that turns to ice, flows downward, and melts at the snout.

Once the temperature reaches a point where net accumulation no longer occurs anywhere on the glacier it quickly disappears.

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