Denis Hayes (1947-), an American lawyer noted for his founding role in the first Earth Day (1970), an event often credited with launching the modern American environmental movement. He was the first director of the Solar Energy Research Institute (SERI) under President Jimmy Carter, which was later transformed into the National Renewable Energy Laboratory (NREL). In 1990, he chaired the first International Earth Day, which enlisted 200 million participants in 141 countries. He led a similar event in 2000, when Earth Day became the first national environmental campaign ever carried out in China. Hayes went on to become President and CEO of the Bullitt Foundation, a US$100 million environmental foundation located in Seattle, Washington (USA).