Increased heat stress reduces future yields of three major crops in Pakistan’s Punjab region despite intensification of irrigation.

Climate change and variability threaten the sustainability of future food production, especially in semi-arid regions where water resources are limited irrigated agriculture is widespread. Increasing temperatures will exacerbate evaporative losses increase plant needs. In this regard, higher irrigation intensities have been posited as a solution to mitigate climate impacts these regions. Here, using agro-hydrological model SWAT biophysical crop APSIM, we show that mitigation measure oversimplified. We find heat stress, driven by strong temperature increases, might be dominating factor controlling yields Our analysis encompasses agricultural areas Lower Chenab Canal System Punjab, Pakistan (15,000 km2), which part Indus River system, largest system world, covering major cotton, rice maize cropping zones. models project over study region up 1.8 °C (±0.5 °C) until mid-century. Both predict decline for crops, while cotton less effected rising strongly benefit from elevated atmospheric CO2 concentrations. For high carbon emission scenario, simulate yield declines −10% (APSIM) −19% (SWAT); −4% −26% (SWAT), −1% +11% 2050, relative baseline scenario 1996–2005. modeling results further suggest demands do not align with increasing trends. Average under temperatures. Overall, our emphasizes role its effects on productivity well demand, implications adaption strategies adverse an intensively region. one most important challenge facing agriculture, hence security. Farmers struggle more ensure reliable production. This true but at same time urgently needed irrigation, such Area, Pakistan. The search adaptation measures weaken negative systems becomes increasingly important. One option could intensification irrigation. use two growth processes various conditions. stress would plants selected even lead reduction demand. Intensive can necessarily help prevent change-related losses. positive effect enhancing growth. Nevertheless, indicate compensate constantly