Al Gore spoke at the commencement ceremony at Carnegie Mellon University (CMU) on Sunday after introducing himself as the man who used to be the next president of the United States of America.

Gore spoke to more than 2,000 graduates and he applauded the school's efforts in taking on topics like the environment.

The 2007 winner of the Nobel Peace Prize told the graduates they have gifts and encouraged them to continue on the path of making a change in the world.

The former vice president also commended the work of CMU professor Randy Pausch. Gore called Pausch -- who is dying of pancreatic cancer -- a hero.

Pausch made a surprise appearance to speak to the class of 2008.

Pausch was told in August that he would likely live only three to six more months. With more than nine months having passed since his diagnosis, he told graduates to remember their passion in whatever they do. All else, he said, will take care of itself.