There are stories now circulating in the media regarding a very dramatic ice melt it Greenland during the past week. As reported by the BBC …
Scientists said the “unprecedented” melting took place over a larger area than has been detected in three decades of satellite observation.
Melting even occurred at Greenland’s coldest and highest place, Summit station.
The thawed ice area jumped from 40% of the ice sheet to 97% in just four days from 8 July.
The scary part is that if all the ice in Greenland melted, then sea level will rise by 4 to 6 m (13 to 20 ft), but don’t panic, we are not there yet.
Has this happened before? Actually yes it has. The deployment of words such as “NASA Stunned” or “unprecedented” might indeed make good media spin, but are not at all justified. Ice cores from Summit (Greenland’s coldest and highest place) show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time.
- If they expected it, and it happened right on time, then why are NASA “stunned”?
- If it happens every 150 years, then what exactly is “unprecedented” about that?
So should we worry? Right now, no, much of the ice that melted is already freezing again. If however this once in 150 year event starts happening on a more regular interval in the next few years … then it is time to start to worry.
I should perhaps also point out that this is about a couple of inches of melt in an ice sheet that is several miles thick in places.
- NASA page on the topic is here.