The fact that thousands of people have lived without love and riches but not one without water, states explicitly how vital water is for us. The widely used natural resource has been a fundamental component of not only our external life, but forms a large chunk of who we are. Yet it is the most misused and downplayed resource in this part of the globe. Changes in climatic conditions have had widespread impacts on human and natural systems. The influence of humans on the climate system is evident through recent anthropogenic emissions of greenhouse gases that are the highest in history. Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. Studies reveal that the atmosphere and oceans have warmed, the amounts of snow and ice has diminished, and sea level has risen. The resource that plays such a pivotal role in our lives therefore, need to be monitored and safeguarded not only for us but for the coming generations.
A trip to Rawal Dam a couple of years ago is still etched in my mind like a grotesque nightmare reminding me how things can change so drastically and so rapidly right in front of our eyes. The cracked, parched land that was once the Rawal Lake that we had so often visited as kids and adults was an eyesore! People walked all over the place where we had sat fishing! Where was the water that was supposed to have been collected in the lake? No one knew! It was true what research reports had said! That shrinking snowcaps are reducing river flows and water supplies across China, India and Pakistan – countries where more than one billion people already lack access to safe drinking water and adequate sanitation.
It is seen that utilization of water has increased manifold! It is not only limited to household requirements, but also spreads in sustaining agriculture that aids in food production, use in industry that manufactures almost all commodities required by man including electronic gadgets, clothes, shoes etc. Electric power plants depend heavily on water, and account for a staggering percentage of fresh water withdrawals across the globe. So, the more cell phones and laptops we buy, the more brands we enjoy, the more cleanliness we adopt, the more trips to the mall we take, all come with a heavy price!
In short, it could be said our economy runs on water that we can ill afford. In order to sustain our fast growing population there is a need to think strategically about the profound risks that will exist in a world where climate change is likely to exacerbate already diminishing water supplies. Drought attributable to climate change is already causing acute water shortages in large parts of Australia, Asia, Africa, and the United States.
Further, water scarcity and declining water quality will impact not only private life, but business too will experience far-reaching effect. We’re already seeing decreases in companies’ water allotments, more rigorous regulations, higher costs for water, growing community opposition and increased public scrutiny of corporate water practices. Moreover, the underground water table is at an all-time low as people digging underwater are now going deeper. Shortage of surface water has put tremendous pressure on ground water as users have started over drawing ground water to compensate for the shortage. In turn, reduced recharging owing to less percolation has resulted in rising of saline water lens nearer to the ground surface, thus turning the water not fit for drinking.
In order to understand this shortage, one needs to understand the greenhouse effect that is spelled as an increase in the atmospheric concentrations of greenhouse gases such as carbon dioxide (CO2) and others that cause Earth to warm up by trapping more heat. Human activities such as burning of fossil fuels, nuclear power plants, industrialization etc. have increased atmospheric CO2 concentrations by about 40%, with more than half the increase occurring since 1970. It has been observed that since the start of the 20th Century, the global average surface temperature has increased by about 0.8 °C. This has been accompanied by warming of the ocean, a rise in sea level, a strong decline in Arctic sea ice, and many other associated climate effects.
Another thing that ought to ring bells of alarm is that much of this warming has occurred in the last four decades. Detailed analyses have shown that the warming during this period is mainly a result of the increased concentrations greenhouse gases. Continued emissions of these gases will cause further climate change, including substantial increase in global average surface temperature and important changes in regional climate. The magnitude and timing of these changes will depend on many factors, and slowdowns and accelerations in warming lasting a decade or more will continue to occur. However, long-term climate change over many decades will depend mainly on the total amount of CO2 and other greenhouse gases emitted as a result of human activities. It is at this juncture that we ought to devise strategies to not only curb the emission of greenhouse gases but also to reverse the effects already settling in.
Despite being fortunate to have 3 major rivers namely Indus, Jhelum and the Chenab flowing from the bordering region to sustain irrigation and hence agriculture, Pakistan faces a number of challenges. Firstly, the Indus river that is mainly a snow-fed river is the main contributor of Pakistan’s agricultural needs. And because of global warming, the extent of snow cover is rapidly decreasing, and this isaffectng its base-flow. Studies suggest that the runoff of the Indus will decrease by 27% in the next three decades which is a huge amount considering its central role in agriculture.
Another major challenge that we face is a rapidly increasing population that adds to an additional demand for water. Pakistan is sixth most populous nation in the world with a population growing at a whopping rate of 1.52% year that is raising many challenges for the scarce and mismanaged resources. Cutting of trees to accommodate more people has led to altering of the hydrological cycle thus resulting in scarcity of rains.
Moreover, the effects of climate change on the Asian monsoon is among the major uncertainties in predicting the water picture in the region. The major risk from the climate change in south Asia is increased summer precipitation intensity in temperate regions; this may increase flash-flood prone areas. Of all natural disasters, floods are the most destructive; in terms of human life they account for over 50 % fatalities (58% deaths were due to floods in the decade 1988-1997). In terms of economic loss, they account for one third. On the other hand, the arid and semi-arid regions would be drier in summer, which could lead to severe droughts.
The Himalayas have a critical role in the provision of water to continental monsoon in Asia. Increased temperatures and increased seasonal variability in precipitation are expected to result in increased recession of glaciers and increasing danger from glacial lake outburst floods. The drought in the monsoons of 2012 and the sudden floods proved to be one of the most catastrophic experience in our history. Further, the availability of fresh water in Pakistan is highly vulnerable to climate change. A reduction in average flow of snow-fed rivers, coupled with an increase in peak flows and sediment-yield would have major impacts on hydropower generation and consequently on agriculture.
Availability of water from snow-fed rivers may increase in the short term, but decrease in the long-run. Runoff from rain-fed rivers may also change in the future. A reduction in snowmelt water will put the dry-season flow of these rivers under more stress than is the case now, especially in Pakistan where one major snow-fed river, the Indus, accounts for as much as 80 % of the normal water flow. Increased population and increasing demand in the agricultural, industrial and hydropower sectors will put additional stress on water-resources.
In this backdrop there is a need to fight this scarcity and slow down the process of water loss. Better management of water-resources is the key to mitigating water-scarcities in the future in the short-term, and avoiding further damage to aquatic ecosystems. More efficient use of water could dramatically expand the available resources. In the longer term, however, the looming water-crises must be addressed through hard policy-decisions that reallocate water to the most economically and socially beneficial uses. Greater emphasis on water-efficient technologies and control of pollution is also essential.
In Pakistan, about 50% of irrigation-water never reaches the crop and is lost to evaporation or runoffs. However, even with measures to contain the increase in demand and use of water more efficiently, new supplies will be needed. The financial and environmental costs of tapping new supplies will be, on average, two or three times those of existing investments, because most of the low-cost, accessible water reserves have mostly been exploited.
Further, increase in sustainable water-resources in the country can be achieved through a combination of groundwater-aquifers and large and small surface-water facilities. This combination will be critical to meeting the water needs of the twenty-first century. Incorporating realistic scenarios of water resources is a fundamental element of sustainable development. Water-resources and climate change not only affect agriculture, but they also affect every aspect of life. Management of water resources thus requires a balanced and careful review of current knowledge under a comprehensive framework while keeping all stakeholders on board.