The heat is on (IMAGE) University of New South Wales Caption Early greening caused by global warming may amplify heatwaves across large parts of the Northern Hemisphere. Credit Sunny Day by Andreas Wienemann (CC2.0) Usage Restrictions CC2.0 - Attribution -- You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. 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.