Consequences of a Melting Greenland Ice Sheet

At its extremity a complete melt would cause a global sea level rise of about 6 metres, although this pales in comparison to the 60 metre rise we would be faced with should Antarctica melt, however unlikely. However, we’ll ignore that part and focus on the Greenland Ice Sheet. 54% of Asia’s urban population resides in low-lying coastal areas (Kumar, 2013), according to geohive.com that stands at a population of over 2.1 billion people. This means that in Asia alone over 1 billion people are at risk of rising sea levels.

Figure 1: Visualisation of the cumulative melt days observed on the Greenland Ice Sheet. Credit: NSIDC

Let’s Look at the Melt, and when will it affect us?

Importantly, the rate of melt is increasing. In fact, between 2002 and 2009 the rate of ice loss more than doubled from 137gigatonnes/year to 286 gigatonnes/year. This halves the lifetime of the sheet. Rather obviously though, Greenland strength is the cooling caused by its immense size, as it shrinks it loses its source of cooling therefore melts quicker. Now that our CO2 levels have increased above 400ppm permanently it is expected that the ice sheet will lose 20 to 41% of it volume over the next 400 years (Stone, 2010), equivalent to roughly 1.4-2.8 m sea level rise. Despite the ARR noting that process we’d expect to see over millennia are occurring on a decadal basis the threat from the Greenland Ice sheet is a long-term one. Short-term effects are negligible, and although that can give us comfort we are continually accelerating that melt.

Consequently, we’ve got time. Not to say that should affect the urgency of climate awareness and action but at least in this regard we can start the planet on a path that will halt this melt process.