More than 40% of Earth’s glacial mass could disappear if humanity keeps investing in fossil fuels, warns a stark new projection.

The bleak scenario would mean more than two thirds of the total number of glaciers would vanish by the end of the century, contributing to ever-increasing sea levels around the world.

Lead researcher David Rounce, who is the assistant professor of civil and environmental engineering at Pittsburgh’s College of Engineering, led an international effort to produce the new projection.

Even in that best-case scenario, Professor Rounce’s team found that almost 50% of glaciers would disappear, accounting for more than 25% of total glacial mass, by 2100.

A previous study warned that the Earth is already destined for 1.5C of warming.

While most of the glaciers lost under Professor Rounce’s projections are small by global standards, measuring less than one kilometre squared, the disappearance of so many of them would add up.

Catastrophic glacier loss is already being felt across the globe.

Last year, Switzerland’s glaciers were found to have shrunk by half in less than a century – and the country’s oldest glacier has had to be covered by special white blankets to prevent it from melting.

The thawing has been so intense that a Sky News team was able to witness an aircraft wreck dating back to 1968, which re-emerged without warning in the Swiss Alps when the ice hiding it started to melt.

Melting glaciers also contributed to last summer’s catastrophic flooding in Pakistan, which is home to more glaciers than anywhere outside the Arctic and Antarctic.

Located in the northern Himalayas, Pakistan has some 7,000 glaciers, and rising temperatures – which reached almost 50C (122F) in the city of Nawabshah in 2022 – are causing them to melt and form glacial lakes.

Scientists have also issued warnings about the melting of Antarctica’s so-called “doomsday glacier”, the complete collapse of which could raise sea levels by 60cm.

The impact would be so far-reaching that it would even have “severe consequences” for the UK.

But Professor Rounce warned that even a complete halt of global emissions would not be reflected in the rate that glaciers are disappearing for decades – potentially taking up to 100 years.

He describes glaciers as “extremely slow-moving rivers”, the impact of which takes time to be felt.

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