1667435666 The 460 World Heritage glaciers that climate change will erase

The 460 World Heritage glaciers that climate change will erase from the map

There are victims of the climate crisis who are irretrievably sentenced to death. After decades of ignoring scientific warnings, the massive amount of greenhouse gases that humans have already emitted has produced warming that will have irreversible effects for hundreds or thousands of years. Topping the damage list is the loss of glaciers, the large masses of ice and snow that accumulate in mountainous and polar regions. UNESCO conducted a study to assess the impact of warming on the 50 world natural heritage sites with glaciers. This UN panel concludes that in 17 of these areas of high ecological, scenic and cultural value, these formations will no longer exist by the middle of this century, regardless of the degree of warming achieved.

There are a total of 460 glaciers that the climate crisis will erase from the map. In this list of those condemned to death are the last glaciers of Africa (located in Mount Kilimanjaro, Kenya and Rwenzori-Virunga) and many others from some emblematic places in Europe and North America, such as the Dolomites (Italy), the Pyrenees -Monte Perdido (between France and Spain) and the American national parks of Yellowstone and Yosemite.

That, according to the UNESCO report, is being lost with the current warming of around 1.1 degrees Celsius compared to pre-industrial times. However, although the tendency to reduce the amount of ice and snow is very negative, what happens to the glaciers of the other 33 analyzed World Heritage sites is still in a way in the hands of the people: “They could be saved if greenhouse gas emissions are drastically reduced, to limit global warming to 1.5 degrees Celsius”, the most ambitious goal of the Paris Agreement. To that end, science has made it clear that it is imperative that humanity ditch fossil fuels as quickly as possible: oil, gas and coal.

Currently, “more than 200,000 glaciers have been identified in the world, of which around 18,600 are in World Heritage Sites,” Tales Carvalho Resende, the lead author of this UNESCO report, tells EL PAÍS. “The World Heritage glaciers cover an area of ​​approximately 66,000 square kilometers, which is almost 10% of the glaciated surface of the earth,” adds Carvalho.

UNESCO has currently recognized 1,154 World Heritage sites, and the study focuses on the 50 that have ice formations of this type, including the tallest in the world – on Mount Everest -, the longest – in Alaska – and the last remaining in Africa. Using satellite imagery, the report analyzes the evolution of these glaciers in the 21st century. The bottom line is that everyone “goes backwards”.

Information is the first tool against climate change. Subscribe to it.

Subscribe to

“All Ice Age World Heritage sites had a negative mass balance from 2000 to 2020, meaning they lost more ice than they gained,” the study notes. The authors calculate that they lost an average of 58,000 million tons of ice per year over those two decades, equivalent to the total water use of France and Spain combined. “Assuming that all meltwater eventually reached the ocean, ice loss from World Heritage sites caused about 4.5 percent of the observed global sea-level rise from 2000 to 2020, about 3.22 millimeters,” the UNESCO report adds. Although all regions have seen glacier retreats in World Heritage areas, those that have accumulated the greatest ice loss this century are concentrated in North America, as well as Greenland and Iceland.

A herd of elephants hikes on Africa's highest mountain, Mount Kilimanjaro (Tanzania).A herd of elephants walks on Africa’s highest mountain, Mount Kilimanjaro, Tanzania Ben Curtis (AP)

The disappearance of these formations not only means the destruction of secular or ancient landscapes, but also affects the “local hydrology”. For example, the report cites “the expansion of glacial lakes” and changes in the flow of some North American rivers as some of the consequences. In other cases, gigantic mountain tsunamis associated with this meltdown have already been recorded, such as the landslide that occurred in October 2015 in the Wrangell-San Elías National Park and Reserve in the USA and reached a height of 190 meters.

Although all of the glaciers located in UNESCO protected sites are retreating due to global warming, “the fastest rates of mass loss” are in the sites with the “smallest glacial areas,” i.e., those that have an area of ​​less than 10 Square kilometers have kilometers and the more sensitive to climate change. According to the UNESCO study, these are the glaciers that will be lost by the middle of the century, regardless of the warming achieved.

Carvalho explains that “the largest glaciers can take hundreds of years to respond to climate change, while the small ones can only take a decade or two.” He adds: “The world’s largest glaciers spread and grow under the weight of accumulated snowfall, but small ones are more dependent on snow carried by a storm or an avalanche and generally remain in one place. During hot summers, the smaller glaciers lose mass as meltwater feeds streams and irrigation systems in the lower valleys. On average, glaciers grow 1.5 to 2 meters each winter and shrink 2.5 to 3 meters each summer. In a particularly hot summer, a very small glacier can lose up to 20% of its mass.” For this reason, the constant rise in temperature due to the climate crisis is leading to its disappearance.

Glacier Point in Yosemite National Park.Glacier Point, in Yosemite National Park.getty (getty)

What happens to the largest glaciers will depend on how climate change related to man-made greenhouse gases evolves. In the most pessimistic scenario, with increasing emissions and a temperature increase of around 4 degrees by the end of the century, the glaciers of another 10 natural world heritage sites – which have an area of ​​between 10 and 100 square kilometers – could “disappear”. almost completely to 2100″. In this case, the loss of ice mass would correspond to a rise in sea level of 20 millimeters.

But if emissions are drastically reduced to limit global warming to 1.5 degrees, ice loss could be reduced and the glaciers at the 33 World Heritage sites analyzed could be “saved”. “These results underscore the powerful impact emission reductions could have on the extent of ice loss and glacier preservation,” the report points out. Along the same lines, Audrey Azoulay, Director-General of UNESCO, adds: “This report is a call to action. Just a quick reduction in current CO₂ emissions [el principal gas de efecto invernadero] There can be hope to save glaciers and the extraordinary biodiversity that depends on them.”

Follow CLIMA Y MEDIO AMBIENTE on Facebook and Twitteror sign up here to receive our weekly newsletter