This study presents FAWSIM – Food and Water Security Integrated Model System, which is a co-evolutionary decision support system for climate change impact assessments. The objective of the system is to assist with the assessment of adaptation options and sustainable development opportunities in relation to water and food security at global, regional and local scales. This is achieved through the effective transfer of climate change and impact information to planners, policy-makers and the wider scientific community. Case studies in Jilin province, China and Mongolia verifies and validates the feasibility of the system. The application of the FAWSIM system extends our understanding of the local food and water security issues in the context of climate change.