Koung-An Chao, a doctor of Rensselaer Polytechnic Institute in USA and a retired chair professor of Lund University in Sweden, was invited to give a speech on the topic of "Where is Our Future Energy". Since he is quite experienced in energy development in Sweden, it was a very good opportunity to share knowledge of worldwide sustainable energy development for effective execution and complete plan in the future.
Fossil fuels (oil, coal, natural gas, combustible ice) are the main cause of environmental problems. The use of them must be clean in the future, while green alternative energy sources develop. New alternative energy sources must be sustainable otherwise it will eventually run out one day.