Climate change may impact on food safety by affecting the prevalence and concentrations of bacteria. This thesis aims to quantify the impacts of climate change on microbial safety of pre-harvested leafy green vegetables (LGVs) contaminated with generic E. coli. The impacts of climate change on microbiological safety of LGVs can be directly through an increasing temperature and indirectly through changes in agricultural management practices. With one degree increase in minimum temperature, the odds of having E. coli presence on LGVs increase by a factor of 1.5. The mean E. coli concentrations are also expected to increase. A climate data downscaling tool was presented to downscale coarse gridded data. A multi-criteria scenario analysis tool was developed to explore future food safety. This thesis quantified the impacts of climate change on microbial safety of LGVs for the first time. This pioneering research brought new methods, tools and mind set to food safety research.