Rapid Glacier Melt In the Himalayan Plateau Threatens Water Supply for Billions | Abridged Ecosystem Transformation
With perhaps hundreds of feet of sea level rise contained in the rapidly melting land ice of Greenland and Antarctica, the situation at the poles is enough of a planetary climate crisis for anyone. But the catastrophe at the Third Pole may be more destructive in it’s short term effects.
The “Third Pole” is a term coined to describe the Himalaya-Hindu Kush mountain range and the Tibetan Plateau. These extensive ice fields hold the planet’s largest reserve of fresh water outside of the Greenland and Antarctica. Up to 1.3 billion people depend on the ten river systems that originate here for drinking water, irrigation and power in eight countries in South Asia. Among the rivers with sources in the glaciers are the Ganges, Indus, Yellow and Yangtze. If the people downstream from the sources are factored in, the number climbs to 2 billion humans (about 25% of the global population).
Warming temperatures are liquefying glaciers across the vast Himalayan region. By one count, 509 glaciers have disappeared over the past 50 years.
Before global warming kicked in, winter snowfall replenished the glaciers. Now, as temperatures climb, snow falls when temperatures are fairly high, so much of the water flows directly into rivers. The decay of the glaciers is visible from year to year. What is happening across the Third Pole is the most prominent example of this slow mo global climate phenomenon as alpine glaciers in South America, Europe and Alaska recede.
As quoted in The Big Thaw, a February 2019 National Graphic article by Daniel Glick, Daniel Fagre of the U.S. Geological Survey Global Change Research Program said, “Things that normally happen in geologic time are happening during the span of a human lifetime. It’s like watching the Statue of Liberty melt.” As the article goes on to point out, the iconic snows of Kilimanjaro have receded more than 80% since 1912. In the Andes, an artist is painting the bare rocks white in honor of the glaciers that used to provide water for the villages.
COMPLEX CAUSE AND EFFECT
In places where glaciers have disappeared completely, the impact on the water supply is devastating. However, where glaciers still exist, they melting more rapidly: the local effect may actually be more fresh water collecting in new lakes. So more water in the short term, followed by no water.
This gives rise to a frightening event at the opposite end of the spectrum: a phenomenon called Glacial Lake Outburst Flood (GLOF), in which an ice dam holding back meltwater suddenly collapses, releasing a wall of water into the valley. This is not a new type of event, but as glaciers recede it is becoming more common.
In the Third Pole Region, smaller spring-fed forest rivers are also drying up, due to climate change, deforestation, migration and unenlightened hydro projects. Rainfall and snowfall have decreased significantly over the past three decades and groundwater has been depleted by indiscriminate drilling (see Ogallala Aquifer depletion).
Monsoons also feed the large rivers, so the receding glaciers are only part of the overall scenario. But the monsoons have also become unreliable.
The impending drinking water crisis is not the only change looming in the Hindu-Kush. Agriculture and herding lifestyles have already been severely compromised as yet another regional migration gathers steam. Less grass grows and it does not grow as high. Herds are depleted remnants of their former selves. Local herbs are disappearing.
As temperatures continue to warm, biodiversity is beginning to crash. The term “biodiversity” sounds scientific and vaguely liberal, but what it refers to is the death of species across the spectrum of life. Whether in the mountains, the oceans or prairies, the consequences of the sixth great extinction are just beginning to manifest themselves across the food chain.
Most species that inhabits an alpine ecosystem have nowhere to go but up. And out.
Humans are different. The pastoralists can leave the alpine valleys and find work in the towns and cities for now. But their herds can’t come with them.