Water: The Driving Force of All Nature

Water is the driving force for all nature. About 60% of the human body, 80-90% of plants and 71% of the Earth’s surface is water. Glaciers are huge masses of ice that flow very slow like a river. They form over hundreds of years where fallen snow compresses and turns into ice. The solid mass of water in the shape of glaciers are the largest reservoirs of freshwater on the planet. In fact, they store 75% of the freshwater.

Formation of The Himalayan Mountain Ranges and Tibetan Plateau took place because of the collision between the Indian plate and Eurasian plate which began some 50 million years ago, and still the Indian plate is moving towards The North at a rate of 4-5 mm per year. The immense mountain range began forming 40-50 million years ago. The Himalayan ranges have 32,392 glaciers in it. Pakistan has a share of some 7253 known glaciers. These glaciers act as reservoirs of freshwater which persist through summer. Continual melt from glaciers contributes water to the Indus River which recharges the subsurface water table as well. The frozen rivers in the northern region of Pakistan are sentinels of climate change. They are the most visible evidence of Global warming today. Glacier’s surface reflects the sun rays helping to keep our climate mild. When glaciers melt, darker exposed surfaces absorb and release heat raising temperatures. Melting ice sheets also contributes to the rising sea levels. An interesting fact about melting of glaciers is that if all the ice covering melted, the sea level would rise about 70 meters above. Imagine the rise of just 10 meters in the Arabian sea. It will destroy all the coastal belts of Karachi and Balochistan. Unfortunately, it will happen, but at a very gradual pace.

Climate change is eating away Himalayan glaciers at a dramatic rate. The main reason for the melt is global warming. Pakistan contributes very little to overall emission of greenhouse gases, yet it remains one of the severely affected countries of the world by global warming. As an ill effect of global warming the annual mean surface temperature in Pakistan has steadily increased during the past century. The increasing temperature due to global warming has resulted in the progressive melting of glaciers which resulted in formation of glacial lakes and gradual increase in the sea levels. Glacial Lake Outburst Flood (GLOF) can be impounded by moraine complexes, glacial ice or even bedrock and, because of breaching, slope failure, over-topping, or other failure mechanisms, lead to catastrophic phenomena in the high mountains that threaten people’s lives, livelihoods, and regional infrastructure.

In the Himalaya, moraine-dammed glacial lakes are common and numerous GLOF events have been traced back to the failure of moraine dams. A moraine-dammed lake forms as glacier retreats, and meltwater fills the space between the pro-glacial moraine (in front of the glacier) and the retreating glacier. As the volume of the glacial lake grows, so does the pressure on the dam containing it. Fragmentation of the source glacier, landslides and other processes can trigger displacement waves in the lake, potentially compromising the stability of the dam and resulting in a GLOF. Failure of the dam can also occur due to internal processes, such as water seeping through the structure.

Although GLOF are not a recent phenomenon in the HKH, they remain a persistent threat to downstream communities and infrastructure and must therefore be part of any planning in the lower reaches. The frequency of GLOF and risk from potential GLOF are expected to increase as the climate continues to change. As temperature rises, new lakes form, existing ones expand and sometimes merge, increasing the potential flood volumes in the high mountains.

The Pakistan meteorological department is monitoring some dangerous glacial lakes through satellites in space. They have also installed stations at remote areas to monitor these lakes.

There is still a lot that we do not know about the dynamics of glaciers and glacial lakes in the Hindu Kush Himalaya. It is, therefore, important to learn as much as possible about past events and the dynamics behind them and to assess the overall GLOF risk in the region for better planning and implementation of disaster risk reduction measures and climate change adaptation in Pakistan.

The melted water is increasing the sea level. According to Karachi tidal station an increase in the mean sea level at a rate of 1.1 mm per year has been recorded during the past 100 years. The rising sea continues to engulf the surrounding land and consumes 80 acres a day on average. These all effects of climate change will make our life difficult in future.