It’s called the third pole of the world. Outside the polar regions themselves, the Hindukush-Himalayan region has the most glaciers in the world — as many as 15,000 glaciers; stretching a 2,400-km range, they sweep through Pakistan, India, China, Nepal and Bhutan, and are the source of water for some of Asia’s largest rivers that flow across the continent.

The meltwater from the Himalayan glaciers is one of the main source of fresh water reserves that sustain about 1.3billion people or almost one-sixth of the world’s population. These people, who live downstream of these flows rely on both melt-water and monsoon waters for irrigation, drinking, sanitation and industrial uses.

These glacier-fed river systems are the lifeline of Pakistan’s mostly agricultural economy as the glaciers supply almost 60pc of the total fresh water to the country.

The Northern areas of Pakistan including Gilgit-baltistan and Chitral, host more than 5,218 glaciers which feed water to the Indus River. This crucial resource is now in danger. “Recent research shows that these precious sources of fresh water are receding at the rate of 40-60 metres per decade; of course the most important causative factor is climate change or global warming, as is the case in the rest of the world,” says Hamid Ahmed Mir, Field Manager, Pakistan GLOF-Project, Chitral.

This is an alarming situation for Pakistan. “The melting of glaciers is expected to produce more melt water during the melting period i.e. from July to September. It will increase flows in the rivers for the next few decades followed by a decrease in flows in the distant future due to reduction in glacier area,” says Ghazanfar Ali, head of Water Resources and Glaciology Section, Global Change Impact Studies Centre, Islamabad.

Scientists believe that more water from melting glaciers, along with the variability of monsoon rains in the coming decades, may lead to increased flooding in the coming years. Pakistan is already experiencing severe floods since 2010.

As the glaciers lose their mass, reduced flow in the rivers due to less water from glacier melt will increase the dependence of river flows on monsoon rains resulting in more variability in the availability of water.

A major portion of Pakistan’s agriculture depends on the Indus River which has the world’s largest irrigation networks. Irrigation water requirements will increase in future with the increase in population but also due to higher temperatures predicted to become the norm. “In this situation there is a pressing need for raising the water reservoir to meet the challenges of increased water requirement for water and food security, flood control, supply of water in dry years, hydropower generation, etc.,” says Ali.

Any change in the discharge from melting glaciers will have a considerable effect on the millions of people living downstream; reduced water availability will in turn threaten food security and loss of livelihood and wellbeing of those in the downstream regions.

Glacier lakes usually form when a retreating glacier erodes the land and then bursts filling the hole or space that it has created with water. Rapid accumulation of water in these lakes may lead to a sudden breach of the moraine dam, causing a possibly catastrophic glacial lake outburst flood (GLOF). The impacts of GLOFs include loss of lives, domestic property, cultivable land, mountain infrastructure downstream, forced migration and long-term secondary environmental degradation.

The political dangers are also considerable. As water sources dry up, the issue of the sharing of this vital resource may also lead to confrontations between countries, and experts warn that water wars may well be on the not-so-distant horizon. —R.N.