28 Jul

Impact of Global Climate Change on the Water Resources of Pakistan


Major sources of Pakistan's fresh water and power generation, the mighty River Indus and other tributary rivers originated from Himalayas and Karakorum mountain ranges are being adversely affected by rapid climate changes in the region.

The changes also affect the physical conditions of heavenly glaciers, which exist on high mountains to formulate proper glacial ecosystem. Other major areas, which are being affected by climate changes included human health, water-related infrastructure and hydropower generation.

Water resources in Pakistan are affected by climate change as it impacts the behavior of glaciers, rainfall patterns, greenhouse gas emissions, recurrence of extreme events such as floods and droughts.

The major sources of Pakistan's fresh water and power generation, the mighty Indus River and other tributary rivers originated from Himalayas and Karakorum Mountain ranges are being adversely affected by rapid climate changes in the region.

Scientists and experts believe that climate change is taking place due to increasing emission of greenhouse gases, which is álso one of the main reasons for global waming. It had also a direct impact on global atmospheric conditions. The changes also affect the physical conditions of heavenly glaciers, which exist on high mountains to formulate proper glacial eco-system. The other major areas which are being affected by climate changes included human health, water related infrastructure and hydropower generation.

Our Northern Areas are home to 5,218 glaciers and 2,420 glacial lakes, of which, more than 50 glaciers have potentially been categorised as dangerous. The glaciers are receding at an average of 40 to 60 metres/10years, which has created complications for the communities residing at the up sea level, who are under the threatof glacial lake outburst floods (GLOFs).

Severe floods have occurred in the years 1950, 1956, 1957, 1973, 1976, 1978, 1988, 1992., 2010, 2011, and 2012. Pakistan has faced the worst-ever droughts during the period from 1998 to 2004, Pakistan has surface water potential of 140 million acre feet (MAF) and underground water reserve of 56 MAF. It is one of the most water-stressed countries in the world. The per capita annual availability of water has reduced from 5140 m3 in 1950 to 1 000 m3 now.

Pakistan's rain pattern is already that of high magnitude and low frequency, which means we have more rain but for a shorter time, which does not help percolation and raise the ground water level. So, climate change is causing longer spells of drought, which is complicating our water scarcity problem.

In future, though, climate change will make matters worse in a number of ways. First, as mentioned above, the total quantity of water is likely to decline, thus increasing the scarcity level. Second, the water availability will become more erratic, thus increasing uncertainty and seasonal stresses and strains. Third, the increased termperatures will reduce water availability further because of higher evaporation rates while increasing crop water requirements and other water demands.

Pakistan has already experienced severe droughts in its southern  region (especially Tharparkar in Sindh province) in 1998-2002 and 2014-17. It will most likely intensify because of the climate change, which threatens the situation in a number cf ways.

Keeping in view the developments in the water sector, around 142MAF water was available in 2015/16 for agricultural use, which now has been reduced by climate change impacts.

First, if glaciers continue to decline, the contriibution of snow and glacier melt will ultimately decrease. Second, climate change will also affect the monsoon patterms (although current projections do not show systematic change in this regard). Third, the higher temperatures throughout the county will increase water demand as well as evaporation. All three factors are likely to contriute to an increased frequency of droughts.

The Indus Basin  System is fed by glaciers from three interconnected mountian ranges , namely the Himalayas, the Karakorum and the Hindukush. Of the three (also known as the HKH region), the glaciers in the Himalayas and the Hindukush are melting. similar to those in the rest of the world. The Karakorum, however some even appear to e increasing. This has puzzled scientists because no one expects glaciers to remain stable when temperatures rise.

Historic Climate and Hvdrology Trends

Pakistan's climate is beginning to change in response to the global processs of cliamte chage. Studies of historical temperature datasets  show a statistically significant warming trends over all of Pakistan , with mean annual temperatures reported to have increased by 0.6°C between 1900 and 1999, Regional differences  have been observed , with the northern portion of Pakistan experiencing an overall warming trend over the past 50 years. while some parts of lower Indus Indus Basin have cooled. At the same time, temperatures in the Upper Indus Basin show constrasting trends between winter and summer, with average and maximum winter temperatures showing a statsticaliy significant increase (0.1 to 0.55°C per decade), while average and minimum summer temperatures showed consistent cooling, Winter warming has been confined to lower altitudes while summer cooling is greater at higher elevations.

ExIsting annual and decadal variability in precipitation levels within Pakistan due to factors such as variable in monsoon patterns make it more challenging to detect emerging precipitation trends spurred by global climate change. Available studies for Pakistan as a whole suggest that there has been an increase in annual and seasonal precipitation in the past 30 to 50 years, although large differences between regions and seasons have been observed. There has been a strong trend toward increasing precipitation levels in the Upper Indus, Punjab and northern Baluchistan plateau, while the westerm Baluchistan plateau and particularly the coastal belt has experienced declining precipitation levels. Within the Indus Basin available studies are less consistent in terms of observed changes but generally suggest that there has been an increase in winter precipitation levels in the Upper Indus Basin since the 1960s.

In 2012, Pakistan was the first country to set up a climate change ministry. This was followed by the release of the National Climate Change Policy. But unfortunately, as usually happens here, nothing more was done to empower the ministry, nor was there any adherence by the government to its own policy.

 Climate change is a much deeper and broader issue than policymakers realise.

In Pakistan, the agriculture sector roughly utilises 95 per cent of all water resources. The share of cultivated area in water utilisation is 80pc in the form of irrigation, which results in 90pc agricultural producticnin the country. The remaining production originates from rain-fed (barani) lands.

The water resources of Pakistan include surface water, rainfall and groundwater. The scope of availability of these resources is location-specific. Surface water resources of the country are mainly based on the flows of the Indus River and its tributaries.

Rivers in Pakistan have independent flow characteristics. However, all of them generally start to rise in the spring and early summer and the flows are minimum during winters.

A World Bank report, Pakistan's Hotspots The Impact of Temperature and Precipitation Changes on Living Standards released in July 2018, claims that by 2050, annual average temperatures are projected to increase to 2.5°C under the climate "sensitive scenario' (which represents a future in which some collective action is taken to limit greenhouse gas emissions) and up 3.0°C under the carbon 'intensive scenario' (in which noserious actions are taken). Approximately 49 million, or 25 percent of Pakistan's total population, lives in locations that will become 'moderate hotspots' by 2050 under the carbon intensive scenario. Containing the temperature is essential to prevent major areas of Pakistan from becoming uninhabitable in a future not too far away. 

Climate change poses a serious threat to the living standards of the vast population of Pakistan. The report further indicates Sindh province as the most vulnerable hotspot. With a GDP per capita of US 1400$ Sindh is the second largest economy of Pakistan and contributes 30 percent to the national GDP. Its economy is highly

diversified, ranging from heavy industry and finance centred in and around Karachi to a substantial agricultural base along the Indus River. Changes in precipitation and temperature threaten to impede the future growth of this region. According to the report, Hyderabad district in Sindh emerges as the top hotspot, followed by Mirpur Khas and Sukkur districts.

The second most vulnerable hotspot is the densely populated province of Punjab. Punjab has the largest economy, contributing 53.3 percent to Pakistan's GDP , and is known for its relative prosperity with the lowest rate of poverty of all provinces. However, its wealth is unevenly distributed , with the northern portion being relatively well off economically and the southern portion being one of the most impoverished areas in the country. Long-term climate vulnerability thus carries implications for both shared prosperity and poverty reduction of this province.

How Will it Affect Inter-Provincial Harmony?

The political implications of water shortages are palpable as well as the provincial inter-provincial bickering emerges over discharges as irigation authorities seek greater control over limited resources. Where Sindh has always held that Punjab, being an upper riparian province, thwarts its fair share of water, both provinces face acute water shortages this season. Diverting water to salvage crops, will further affect an already parched Balochistan. It will also impact the law and order of the city as scuffles people clamour for the privilegeof drinking water. With no irrigation water, livestock also faces starvation.

Further exacerbating factors are India controlling over 85pc of water from Indian-held Kashmir, water wastage (owing to poor agricultural practices), a water loss of 111bn cusecs of water in past three floods, diminishing capacity of reservoirs, excessive (nearly 60pc) conveyance losses, deteriorating infrastructure, high operation costs and an excessive ground water use.

There are reports of 'discrepancies'  in water discharges and their measurement at key inter-provincial distribution sites. Sind has complained about incorrect measurement between the Chashma and Taunsa barrages and Taunsa and Guddu barrages. Balochistan has charged that Sindh is not allowing it to have its full share of water in accordance with the agreement Sindh, Balochistan and Punjab have similar complaints against KP and protested over huge water losses between Besham barrage and Tarbela and inaccurate measurements at Chashma barrage. The dispute involve all four provinces can lead to a serious discord if not resolved at the earliest.

 What makes the Issue serious is that those involved in disnutes are now flouting the authority of IRSA.

 The Water Apportionment  Accord is an agreement on the sharing of waters of the Indus Basin between the provinces of Pakistan. It is based largely upon the historical use of water by the provinces; Punjab 47%, Sindh 42% Khyber Pakhtunkhwa, 8% and Baluchistan 3%.

the Accord was signed into effect 25 years ago on 21 March 1991 and is the most significant piece of water legislation in Pakistan after the Indus Waters Treaty, which is an agreement on sharing of waters between India and Pakistan.

Despite all the strenuous efforts, water availability is either stagnant or dwindling, According to Global Change Impact Studies Centre (GCISC) research reports, fresh water resources are among the sectors that are most vulnerable and have potential to be strongly impacted by the changing climate issues.

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