Can Pakistan achieve sustainable water security? Climate change, population growth and development impacts to 2100

We use an integrated population–GDP–food–water model to examine development scenarios for Pakistan relevant to food and water security. The scenarios include as follows: base case (business as usual), population growth; economic growth; wealth inequality (which affects population growth, economic growth and food demand); agricultural yield increases; impacts on water availability of storage dam construction, sedimentation in storage dams, and desalination; and impacts on water availability and crop water demand of climate change. The results indicate that the water security outlook for Pakistan is likely to worsen in coming decades, and groundwater demand for irrigation is likely to increase. However, in the second half of the century, the combined effects of slowing population growth and increases in crop yields could see the situation start to reverse, with decreasing demands for groundwater for domestic food production. While some scenarios, such as a higher rate of population growth or lower rates of yield increase, lead to a worsened water security outcome, others lead to greater water security. Combining several strategies to reduce water demand leads to greater future water security and sustainable water use in Pakistan. However, there may be trade-offs amongst sustainability goals. Climate change impacts on water availability are uncertain, and may lessen or exacerbate water security challenges.