The climate crisis touches almost every region of the world. But perhaps one of the most visible indicators of its impact is its effect on Earth’s iconic glaciers, an important source of fresh water supply. Glaciers have been melting at a breakneck pace in recent decades, accounting for about 20% of global sea-level rise since 2000.
Now, researchers at the United Nations Educational, Scientific and Cultural Organization have found that glaciers in a third of the world’s most beautiful parks and protected areas are set to disappear by 2050 – whether or not global warming slows.
Among the glaciers on the brink of extinction at World Heritage Sites are those in two of the United States’ most popular parks – Yellowstone National Park, which experienced unprecedented flooding earlier this year, and Yosemite National Park.
The list also includes some of the largest and most iconic glaciers in Central Asia and Europe, as well as the last remaining glaciers in Africa, namely Mount Kenya and Mount Kilimanjaro.
Glaciers at World Heritage sites dump about 58 billion tons of ice each year, UNESCO reports, which is equivalent to the total volume of water used annually in France and Spain combined. And these glaciers have already contributed to nearly 5% of global sea level rise over the past 20 years.
The study provides the first global assessment of both current and future glaciation scenarios at World Heritage sites, according to Tales Carvalho Resende, project manager at UNESCO’s natural heritage unit and author of the report.
“This exhibition brings a very strong message in the sense that World Heritage Sites are iconic places – places that are extremely important to humanity, but especially to local communities and indigenous peoples,” Resende told CNN. “Ice loss and glacier retreat are accelerating, so this sends a worrying message.”
Only by limiting global warming to 1.5 degrees Celsius above pre-industrial levels can we save glaciers in the other two-thirds of these parks, scientists report – a climate goal that recent reports say the world is far from meeting. to succeed. The global average temperature has already risen about 1.2 degrees since the industrial revolution.
Glaciers cover about 10% of the land, providing fresh water for households, agriculture and industry downstream. Under normal conditions, they take up to a millennium to fully form. Each year, they gain mass through snow or rain and lose mass by melting in the summer.
Melting glaciers may seem like a distant problem, but Resende said it’s a serious global issue that can hit downstream communities hard. He highlighted Pakistan’s deadly floods this year, which left nearly a third of the country under water. Reports say the weeks-long flooding was likely triggered by a combination of stronger-than-usual monsoons and several glacial lake outbursts due to melt following recent extreme heat that has gripped the region.
“As the water melts, that water will accumulate in what we call glacial lakes. and as water comes, those glacial lakes may burst,” he said. “And that eruption can create catastrophic flooding, which we can see very recently in Pakistan.”
Thomas Slater, a glaciologist at the University of Leeds in London, noted that these glaciers contribute a small fraction of sea-level rise compared to the amount of ice loss that the Antarctic and Greenland ice sheets could cause. Researchers like Slater have already found that these ice sheets are the major contributors to global sea level rise this century.
“While it is sad to hear that some of these glaciers may be lost, we should be hopeful that reducing emissions can save the majority of them and avoid disrupting the water supply of millions of people around the world who live downstream,” Slater, who is not involved in the UN report, told CNN.
As the climate crisis accelerates, more water will be released from the glaciers. In drought-stricken areas like the western U.S., the increase in meltwater can be a good thing, but Resende said it’s only temporary.
Once a glacier’s water peak—the maximum meltwater it contributes to the system—is reached, annual runoff declines as the glacier shrinks to the point where it is no longer able to produce water.
According to the report, many small glaciers in the Andes, Central Europe and Western Canada have either already peaked or are expected to peak in the coming years. Meanwhile, in the Himalayas, annual glacier runoff is projected to spike around 2050, before steadily dipping thereafter.
If countries fail to keep global warming below 1.5 degrees or even 2 degrees, glaciers will only continue to retreat, the report shows. In this future, places will see significant glacial runoff during wet periods, with little to no flow to quench drier, warmer conditions.
“This is a hot topic right now in the research community — to see what the landscape will be after the glaciers melt,” Resende said. “Unfortunately, the glaciers will continue to melt because there is always a delay. Even if we stopped or drastically reduced our emissions today, they will continue to decline because there is this inertia – and it is extremely important that we manage to put adaptation measures in place.”
The report comes as world leaders gather in Sharm el-Sheikh, Egypt, next week for UN-brokered international climate talks, where the focus will be on countries committing to stronger cuts in fossil fuels that will limit global warming. planet at 1.5 degrees. They will also discuss plans to adapt to worsening extreme weather events, including heat waves, floods and storms.
“We really need to pull ourselves together to make that 1.5 goal as much as possible,” Resende said. “The effects can be irreversible, so this is really a pledge to take urgent action.”
