Many glaciers in various regions will not survive the 21st century if they continue to melt at the current rate, potentially endangering hundreds of millions of people living downstream, UN climate experts said on Friday, on the occasion of the first World Glacier Day.
Along with the ice sheets of Greenland and Antarctica, glaciers absorb about 70% of the world’s freshwater reserves. They serve as striking indicators of climate change, as their size generally remains stable in a stable climate.
But with rising temperatures caused by human-induced climate change, they are melting at an unprecedented rate, said Sulagna Mishra, a scientific officer at the World Meteorological Organization (WMO), in a statement.
Last year, glaciers in Scandinavia, the Norwegian archipelago of Svalbard, and Northern Asia experienced the largest annual loss of global mass ever recorded.
In the 800 km long Hindu Kush mountain range, which stretches from Afghanistan to Pakistan, the livelihoods of more than 120 million farmers are threatened by the loss of glaciers, Ms. Mishra explained.
The mountain range has been dubbed the “third pole” due to the extraordinary water resources it harbors, she noted.
Significant masses of perennial ice are disappearing rapidly, with five of the last six years marked by the fastest recorded retreat of glaciers, according to the WMO. “We are witnessing an unprecedented change in glaciers,” which in many cases could be irreversible, lamented Ms. Mishra.
The Global Glacier Monitoring Service (WGMS) of the University of Zurich, a UN partner, estimates that glaciers, excluding the ice sheets of Greenland and Antarctica, have lost more than 9,000 billion tons of mass since 1975.
“This is equivalent to a massive block of ice the size of Germany and 25 meters thick,” said Michael Zemp, director of the WGMS. The world has lost an average of 273 billion tons of ice each year since 2000, he added, highlighting the findings of a new international study on glacier mass change.
Glacier melting has immediate and large-scale impacts on the economy, ecosystems, and communities. Recent data indicate that 25 to 30 percent of sea level rise comes from glacier melting, according to the Global Glacier Monitoring Service.
Snowmelt contributes to a sea level rise of about one millimeter per year, and each millimeter floods an additional 200,000 to 300,000 people each year, according to the climatologist.