Yield Reduction (image) University of Washington Share Print E-Mail Caption These maps show how average temperature increases of 2 degrees or 4 degrees Celsius, depending on future emissions, will reduce average annual corn yields. The study also looked at crop variability and the overall effects on international markets. Credit Michelle Tigchelaar/University of Washington Usage Restrictions With credit Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.