Can climate change risks spur needed action?
Pakistan is facing a serious water crisis. The country is rapidly moving from being classified as water “stressed” to water “scarce”—and with its annual water availability fall below 1,000 cubic metres per person, it may in fact have already crossed this threshold. For comparison, that means that the annual water available for each person in Pakistan would not even fill half of an Olympic swimming pool.
The scope of the crisis can be demonstrated by a few key facts:
1.About 92 per cent of Pakistan is classified as semi-arid to arid, and the vast majority of Pakistanis are dependent on surface and groundwater sources from a single source—the Indus River basin.
2.Since gaining independence in 1947, Pakistan's population has more than quadrupled; by 2100 its population will have increased by tenfold.
3.About 90 per cent of the country's agricultural production comes from land irrigated by the Indus Basin Irrigation System (Qureshi, 2011), firmly linking national food security to water levels in the Indus River basin.
4.Pakistan’s water storage capacity is limited to a maximum 30-day supply, far below the 1,000-day storage capacity recommended for a country with its climatic characteristics.
With water availability per person declining year by year, and demand for food production continuously increasing, Pakistan faces not only a water crisis but also serious concerns regarding its future food security. This situation also has clear implications for the government's efforts to become an upper middle income country by 2025 and achieve long-term peace and security.
What Does Climate Change Mean for the Water Crisis?
Climate change is likely to only enhance Pakistan’s water crisis, although perhaps not in the way that many expect.
When climate change and its implications for Pakistan’s water resources are discussed, the conversation normally revolves around the expected decline in water flow in the Indus River basin as the glaciers of the Hindu Kush-Karakorum-Himalaya mountains retreat and are lost. This concern is understandable given that snow and ice melt runoff currently generates between 50 and 80 per cent (Yu et al., 2013) of average water flows in the Indus River basin. And there is in fact some evidence that the amount of water flowing into the Indus River basin has declined in recent years (but due to cooler and cloudier summers).
Inevitably, climate change will lead to significant changes in hydrologic patterns in the Indus River basin. But at least until 2050 the scientific evidence suggests that the volume of water flowing in the Indus River and its tributaries likely will remain relatively stable or even increase. The most significant change could be a shift in the timing of peak flow to slightly earlier in the year, along with a potential increase in variability from one year to the next. Such changes could in fact help to somewhat alleviate Pakistan’s growing water stress.
Largely overlooked in the discussions around water and climate change in Pakistan are the likely impacts of climate change on the country’s steadily growing water demand. Rising temperatures will increase the agriculture sector’s already substantial demand for water as evapotranspiration rates increase and soil moisture levels decline. Higher temperatures will also affect the country’s growing thermal power production sector, which provides approximately 65 per cent of the country's energy. The thermal sector is highly dependent on water for steam production and subsequently for cooling the steam. As higher air temperatures decrease the efficiency of the thermal conversion process (Makky & Kalash, 2013), greater volumes of water will be required by this sector to maintain production levels.
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