This article presents linear regression relationships using weather and reported crop data to assess the potential impact of observed climate change on the yields of the top ten global crops – barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugarcane and wheat at ~20,000 political units. Results indicate that impacts of climate change on yields of different crops are mostly negative in Europe, Southern Africa and Australia, generally positive in Latin America, and mixed in Asia and Northern and Central America. These impacts have likely caused a ˜1% average reduction in consumablle food calories in the ten studied crops and estimated caloric avaialabillty decreased in nearly half of the food insecure countries.