Temps de lecture :2 minutes
Scientists have often been criticised for not being sure: they are frightening us with uncertain data and unverified hypotheses. But in some cases, their caution has made us underestimate the danger. This is the case when it comes to Greenland’s ice melting.
Until recently, specialists did not think there would be any disruptions in the area. In their 2001 report, IPCC researchers noted that the global assessment of the ice that had melted in Greenland was not considerably different from zero. But in 2007, they estimated that between 50 and 100 billion tons of ice had melted over the 1993-2003 decade. There was even an increase in the following years. Since, every new study highlights acceleration in the fusion between ice and masses. It could even go up to between 200 and 300 billion tons a year.
Many factors explain this acceleration. The main one seems to be that ice melting, even slightly and normally during the summer, creates water currents that go deep down into the ice cap until they reach the rocky substrate that is the biggest island in the world. The water therefore acts as a lubricant between the ice and the rocky surface and makes the ice slide towards the sea. There are others: as they melt, certain areas get thinner and the lighter more fragile ice slides down to the sea even faster. Moreover, western industry generates fine dust that settles on Greenland’s immaculate ice. It is less white. It therefore reflects less and absorbs more solar heat.
If Greenland’s ice melts completely, water levels will rise by almost 7 metres. This means that countries such as the Maldives and Bangladesh and towns like New York and Shanghai will be submerged. There is still time: at the current rate, it will take about 10 000 years for all of Greenland’s ice to disappear completely. But, once again, the problem is that the phenomenon is accelerating.