Douglass Jacobs, Purdue University (IMAGE) Purdue University Caption Douglass Jacobs is concerned that warmer, drier conditions and extreme weather conditions predicted in climate change scenarios could have adverse effects on walnut trees. Credit Purdue Agricultural Communication photo/Tom Campbell Usage Restrictions None License Licensed content 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.