World's glaciers melting at faster pace, study says

The study in the science journal Nature provides one of the most wide-ranging overviews yet of ice mass loss from about 220,000 glaciers around the world, a major source of sea level rise.

Using high-resolution imagery from NASA's Terra satellite from between 2000 and 2019, a group of international scientists found that glaciers, with the exception of the Greenland and Antarctic ice sheets which were excluded from the study, lost an average of 267 gigatonnes of ice per year.

A gigatonne of ice would fill New York City's Central Park and stand 341 meters (1,119 feet) high.

The researchers also found that glacier mass loss accelerated. Glaciers lost 227 gigatonnes of ice annually from 2000 to 2004, but that increased to an average of 298 gigatonnes each year after 2015.

The melt was significantly impacting sea levels by about 0.74 millimetres a year, or 21% of overall sea level rise observed during the period.

Glaciers tend to have a faster response to climate change compared with ice sheets in Greenland and Antarctica, and are currently contributing more to sea level rise that either individual ice sheet, scientists said.

The study could fill important gaps in understanding about ice mass loss, leading to more accurate predictions, said co-author of the study Robert McNabb, a remote sensing scientist at Ulster University in the United Kingdom. Previous studies looking at individual glaciers only account for about 10% of the planet, he said.

Scientists have long warned that warming temperatures driven by climate change are eating into glaciers and ice sheets around the world, contributing to higher sea levels that threaten the world's populous coastal cities. The latest reports https://reut.rs/3xuIn0b by the Intergovernmental Panel on Climate Change project that future sea levels will rise by more than a meter by 2100.

Some glaciers in Alaska, Iceland, the Alps, the Pamir mountains and the Himalayas were among the most impacted by melting, researchers found. Glaciers with surrounding communities provide an important water source and their decline could lead to serious food and water shortages.