Erosion and landslides from the aggravated rains would jeopardize the fragile livelihoods of people in the mountain ecosystems Another frequently used model, by contrast, foresees summer monsoon rains decreasing, placing heavy stress on winter wheat, the main food staple. In either case, changes in agriculture and redesign of irrigation will be essential. With projected doubling of heavy rainfall, adaptation to more frequent flooding is a very high priority. The 1992 and 1993 floods make clear that Pakistan needs to provide for more flood control. Survival of the people in this densely settled, mostly arid land is critically dependent on irrigation supported by the Indus River and its tributaries.
Cereal crops are already under stress.
Pakistan already has most of its arable land under cultivation, and agriculture now produces one-fourth of the GDP and employs one half of the labor force. A high priority is research to provide a clearer understanding of how forecasted heat stress will affect crops, investigations to develop heat resistant crop varieties and experiments with changed planting dates. Even though average rainfall may increase there may also be more drought, although glaciers in the northern mountains could moderate this effect. Semi-desert areas outside the Indus Basin may suffer most severely if drought appears. Rangelands are overgrazed and producing only one-third of the potential nutrients they might yield.