Himalayan glaciers are likely to shrink by 10 per cent by 2100, much slower than in the Alps and other regions, scientists have determined through possibly the most rigorous analysis of global warming effects on glaciers.
Alpine glaciers may shrink by as much as 75 per cent by the turn of the century, a team of American and Canadian scientists has said in research published in Nature Geoscience on Monday.
But the melting of ice sheets in the Arctic regions of Canada and Russia, Alaska, northern Norway and Antarctica are likely to contribute most to the rise in global sea level of an estimated 12 cm by 2100 because of their large size, the scientists have said.
“The surprising finding for me is that the 12 cm rise by 2100 is only from glacier melting…our predictions probably present the lower bound (of sea level rise from ice melting),” Valentina Radic, geophysicist at the University of British Columbia, Vancouver and one of the lead authors told HT.
The results are significant because they are based on the use of the multiple models of measurement used today, and so represent the average amount by which glaciers in different parts of the world are likely to shrink by 2100.
The results come three years after the controversial claim by a Intergovernmental Panel for Climate Change (IPCC) report that the Himalayan glaciers would disappear by 2035. The IPCC subsequently withdrew its claim but has not made any prediction for Himalayan glaciers since.
The findings also help pinpoint global hotspots that have so far not received adequate attention, Radic and her co-author Regine Hock have said.
The scientists used 10 global climate models (GCMs) to model the volume changes of over 1,20,000 glaciers worldwide. Apart from the Alps, glaciers in New Zealand are expected to shrink the fastest – by an average across GCMs of 72 per cent -- by 2100.
But their large ice sheets mean that Arctic Canada (2.7 cm), Alaska (2.6 cm), Antarctica (2.1 cm), Northern Norway’s Svalbard region (1.4 cm) and then Russian Arctic (1.3 cm) are likely to contribute maximum to the rise in sea level by 2100.