Assessing the impact of climate change on sugarcane and adaptation actions in Pakistan

Climate change is a challenging global issue for the sustainable production of various crops around the world as change in climatic patterns can create a stressful environment for plant growth. This study assesses the impact of climate change on future water demand and sugarcane yield in Pakistan for the baseline (1981-2005) and future timescales (2020s, 2050s and 2080s). For evaluating the crop water requirement and yield under future climate, CROPWAT 8.0 and AquaCrop models were used, respectively. For the estimation of future climate, three different Regional Climatic Models were applied under two projection scenarios i.e. RCP 4.5 and RCP 8.5. Maximum temperature, precipitation and minimum temperature displayed an increasing trend under the projected future climatic conditions. The results revealed a growth in the crop water requirement with a subsequent escalating irrigation demand caused due to rise in projected temperature; this is because the projected increase in precipitation under forecasted weather conditions cannot compensate for the increased evaporative demand. Moreover, the results showed a general increasing trend of sugarcane yield under projected climate. By delaying the crop calendar, an overall decrease in crop water requirement in the range of 10.7-12.6% and increase in the yield in the range of 0.37-6.48 tha(-1)can be observed under both climate change scenarios. Moreover, 90% of control irrigation level proved beneficial in terms of saving around 10% irrigation water with acceptable yield reduction. The outcomes of the study are supportive for growers to gain more yield using less amount of water and to adapt to changing climate. The results are also helpful for policy makers to develop adaptation strategies to improve sugarcane productivity and to address water stress in Pakistan.