摘要：Many recent studies show that most of the crop production systems in developing countries are not environmentally sustainable. This study uses the life cycle assessment (LCA) to investigate the potential impacts of corn production in Pakistan on global warming and human health damages and also suggests mitigation strategies to reduce environmental impacts towards sustainable crop production based on the results. Land-based, mass-based, and energy-based functional units were used. IMPACT 2002+ methodology—a combination of IMPACT 2002, Eco-Indicator 99, CML, and intergovernmental panel on climate change (IPCC)—is used for the impact assessment. The results demonstrated that the global warming potential of one-ton production of corn, one-hectare corn farm, and production of 1000 MJ energy were 354.18, 34,569.90, and 1275.13 kg CO<sub>2</sub> equivalents, respectively. The off-farm and on-farm emissions of nitrogen-based chemical fertilizers were the hotspots in the most impact categories. Moreover, human health damages followed by global warming as environmental externalities were also associated with corn production. We also highlighted the production areas with light, medium and extreme environmental externalities with Toba Tek Singh and Okara districts in the Punjab province of Pakistan being the most and least contributing districts towards global warming, respectively. Results further indicated that a 5 to 100% reduction of chemical fertilizers would mitigate the environmental impacts of corn production by 4.38 to 87.58% and 2.16 to 43.30% in terms of aquatic acidification and global warming, respectively. Modern farming systems and conservation technologies were suggested to reduce emissions and improve the environmental performance of corn production. Furthermore, agricultural extension and the ministry of agriculture should pay more attention to farmers’ education on emissions from farming inputs and their impact on climate.
