At least half of the world’s glaciers are doomed to destruction

Posted on Friday, January 06, 2023 at 09:14 am

The disappearance of glaciers contributes to sea level rise, but will also affect water resources, which are an important source of water for about 2 billion people.

Scientists believe there is nothing more to be done for half of the world’s glaciers, but they are calling for global warming to be limited as much as possible to save the rest. Indeed, according to a study published in the prestigious journal on Thursday, January 5 Scienceif temperature increases are limited to 1.5°C compared to pre-industrial levels, the most ambitious goal of the Paris climate agreement, then 49% of the world’s glaciers will disappear by 2100.

This loss will be about 26% of the total mass of the icebecause the smallest glaciers will be affected first.

Researchers believe thatTherefore, the sea level will rise by about 9 centimeters (for example, it will be added to the increase associated with the melting of glaciers). “Regions with relatively little ice, such as the Alps, the Caucasus, the Andes, or the western United States, will lose almost all of their ice by the end of the century, regardless of the emission scenario,” explains University Professor Regin Hock. Oslo and co-author of the study. “These glaciers are more or less doomed.”

If the temperature rise reaches 4°C, the worst-case scenario assumed, then the largest glaciers, such as those in Alaska, will be more affected. 83% of the glaciers will disappear, which is 41% of their total ice mass, and the sea will rise by 15 centimeters.

Regine Hock, who has studied glaciers her entire career, told AFP that “at 9cm to 15cm you can’t see much”. But those levels are “a big cause for concern” because the higher they are, the more flooding they will cause during storms and therefore cause “more damage”. This is already the case, sea level has already risen (about 3 mm per year).

The world is currently on track for 2.7°C warming. This will lead to near-total glaciation in central Europe, western Canada and the United States, and even New Zealand.

Limiting disaster ‘possible’

The work provides the most accurate predictions to date of the future of nearly 215,000 glaciers worldwide. These projections, which are far more dire than those currently used by the UN’s climate experts (IPCC), are made possible by new data on massive changes in every glacier in the world in recent decades. This data allowed us to better calibrate the mathematical model used to predict the future. It also took into account processes not integrated in previous studies, such as the effects of glaciers being covered by debris (rock etc.) or the breaking off of sea icebergs from some glaciers (calving).

The glaciers studied make up “only 1% of all ice on Earth,” but they are “more vulnerable” than other expanses of ice because they are often located in regions where temperatures are closer to the melting point. Thus, they “contributed to sea level rise almost as much as the ice sheets of Greenland and Antarctica over the past three decades,” emphasizes Regin Hock.

The disappearance of glaciers will also have consequences for water resources. They are an important reservoir for nearly 2 billion people. “In summer, many regions are hot and dry, and glaciers compensate for this water loss,” explains the researcher. And their loss “will not only change seasonally, (…) there will be less water in general.”

Boat traffic on the lower rivers or tourism around these small glaciers, which are the most accessible, will also be affected.

Disaster containment is still possible, Regine Hock emphasizes. “I think there is a small ray of hope and a positive message in our research because it tells us that we can make a difference, that action is important.” he assures AFP. But “as for whether it will happen or not, it depends on the political decision-makers”, he believes.

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