16 - Gletsjerne smelter

Gletsjerne smelter 16
Set 3 www.climatefresk.org 16 Næsten hele klodens ismasse er i tilbagegang , og flere hundrede gletsjere er forsvundet . Gletsjerne leverer smeltevand om sommeren , og spiller dermed en vigtig rolle i forsyningen af ferskvand .

1
Cause

Jordens energi-budget

Jordens energi-budget


2
Consequences

Havets vandstand stiger

Gletsjerne smelter

A melting of 100 gigatons of ice per year is equivalent to about 0.28 mm per year of mean sea level rise. Thus, 15 to 35% of sea level rise is linked to the melting of glaciers, according the IPCC scenarios. 30% to 35% is linked to the expansion of water. The remainder is linked to the melting of the ice caps.
Ferskvands-ressourcer

Gletsjerne smelter

Melting glaciers threaten water supplies. Indeed, the relative importance of glacier melt water in summer can be considerable, contributing for example to 25% of August flows in the basins draining the European Alps, with an area of about 105 km2 and only 1% glacial cover. Their disappearance could be catastrophic for cities located in valleys watered by rivers flowing down from the surrounding mountains and for freshwater fauna. Glacier meltwater also increases in importance during droughts and heat waves.

1
Other possible consequence

Oversvømmelser af vandløb

Gletsjerne smelter

It is possible, in certain circumstances of high heat, that very fast rapid melting of glaciers may cause flooding. But the real concern about these glaciers is that they are gradually disappearing, depriving downstream irrigation of a top-up in summer.
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