Glaciers

Half of world’s glaciers projected to melt out by 2100 — study

January 14, 2023 People's Tonight 116 views

ISTANBUL – By the end of the century, half of the world’s glaciers are set to vanish, resulting in not just the loss of their mesmerizing natural beauty, but in heightened water scarcity and risk of natural disasters as well.

A recent scientific report, Global glacier change in the 21st century: Every increase in temperature matters, uncovered the vastly changed world we might face by 2100 when even the best-case scenario would result in huge amounts of glacier loss.

David Rounce and Matthias Huss, the report’s co-authors, spoke separately to Anadolu about the results of the report, in which they evaluated about 200,000 glaciers in the world under various temperature scenarios, and underlined the importance of reducing carbon dioxide emissions for saving glaciers.

“Taking action helps, but some loss is inevitable”

Rounce, an assistant professor of civil and environmental engineering at the US’ Carnegie Mellon University, said that even the best-case scenario would fall short of reaching the Paris climate deal’s goal of no more than a 1.5C rise.

Even under that goal, he said Central Europe is destined to lose “85% of glaciers by mass and 83% of glaciers by number” by 2100, and added: “So even in the best-case scenario, Central Europe is experiencing a lot of loss.”

For the global best-case scenario, the expert said all glaciers, excluding the ice sheets, are “losing about 26% of their mass, contributing about 90 millimeters (3.54 inches) to sea level rise from just the glaciers, and losing about 50% of the glaciers by number.”

For the 2.7C scenario, about a third of the glacier mass is being lost by the end of the century, two-thirds of the glaciers by number, and about 150 millimeters (5.9 inches) of sea level rise coming from glaciers, he added.

Asked whether it is possible to reverse the situation, Rounce said a lot of the climate change impacts are already shrinking glaciers.

He said: “Taking action will certainly help preserve some of the ice in the region but because those glaciers are responding at least some of that loss is inevitable.”

Huss, a glaciologist who heads Glacier Monitoring (GLAMOS) in Switzerland, urged the need for “strong climate change mitigation efforts” to save about three-quarters, 75%, of all glaciers.”

“This is mainly because the big glaciers are in the polar regions, they can still be saved. Whereas the smaller glaciers like the ones that are in the Alps but also the ones in Türkiye, for those it is already too late,” Huss said.

“It’s not too late to take action but the situation is not reversible, at least in the short- or mid-term,” he said, adding that the world is in the midst of “a quite important rise” in global temperatures and therefore also “a loss in glaciers.”

Yet it is still “important to act now” because, according to the scientist, we can still mitigate “the most adverse consequences, the most adverse impacts of global sea level change and climate change globally.”

Except for a few ice patches, Europe’s glaciers will be thing of the past if nothing is done to fight climate change, all glaciers in Europe will be gone, except for a few ice patches at the very highest elevations, said Huss.

For his part, Rounce said that in a 4C temperature change scenario, Europe will lose 99% of the mass of its glaciers, but as of now the estimate is closer to 2.7C, and in that case, estimates show Europe will lose some 94% of its glacier’s mass by 2100.

“So Europe is one of those regions that is very sensitive to changes between a degree and a half, two degrees and three degrees,” he said.

“That’s really one of the areas where in our study when we say every increase in temperature matters, it’s because our actions as a society can have a huge impact on preserving at least some of the ice in Europe.”

Effects of glacier loss

Rounce mentioned glaciers’ contribution to the sea level rising, as the melting of those glaciers would raise the global mean sea level, the baseline, causing extreme events to be even more intense.

“It’s the nuisance flooding that happens on the coasts, the extreme storm systems that come through and cause this devastation and this massive flooding. When we increase the sea level rise by for example, 100 millimeters (3.9 inches), that’s going to increase that baseline meaning (so) that those extreme events are going to become even worse if large scale-adaptation strategies aren’t taken,” he said.

On the sea level rise, Huss warned that rising ocean levels might go even higher, rising to three meters (9.8 feet) by 2300, which would pose a “huge problem” for many coastal cities.

Touching on the importance of glaciers as a water source, he said glaciers provide a great deal of water to streams in hot, dry periods of the year.

“Summer drought is strongly mitigated as long as glaciers are present. If glaciers have disappeared in the future, we will be having a lack of water in hot and dry summers,” he explained. “And this might be a problem for the stability of stream flow for irrigation, but also for hydropower production.”

Huss also mentioned possible effects on glacier tourism in the Alps, saying people from around the world flock to the Alps to see its beautiful glaciers, as well as to ski.

If Switzerland loses its glaciers, this is a problem for tourism, but also the country’s water resources, he added.

Global action needed

It is “vital” that all countries take action to meet the commitments to reduce carbon emissions under the Paris Agreement in order to try to mitigate and avoid some of the damages that we are going to see, Rounce said.

“And it’s important because it’s very easy to get caught up in the fact that a lot of the glacier mass loss is inevitable and a lot of the glaciers being lost … but we really do have the ability to preserve a lot of ice,” he said.

Huss underlined the need for changes in many areas, both economically and socially, to reduce emissions everywhere on Earth.

“The most important is really that we do it as a global community and not at (just) a national level,” he said. Anadolu/Philippine News Agency

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