MADISON, Wis. -- Former Vice President Al Gore is in Madison for a convention of the Society of Environmental Journalists.

The convention of journalists began Wednesday, and Gore delivered the keynote speech on Friday morning.

In his speech, Gore emphasized the dependence on carbon-based fuels as a common link among climate change, the economy and national security.

"Though carbon dioxide is only one of six pollutants to blame for crisis, it is the largest and the mechanisms for securing reductions will bring in their wake the ability to bring about reductions in all the others," Gore said.

Gore said the shift to alternative energy is not just the world's greatest challenge but also its greatest opportunity to make a positive change.

U.S. Department of Agriculture Secretary Tom Vilsack and Jane Lubchenco, who works as an undersecretary for oceans and atmosphere in the National Oceanic and Atmospheric Administration, also attended the event.

On Friday Gore, a former Nobel Prize winner himself, also reacted to President Barack Obama being awarded the Nobel Peace Prize.

"I think it is extremely well deserved. I think that much of what he has accomplished already is going to be far more appreciated in history than it was by the Nobel committee," Gore said.

Some argue that the prize is more directed to Obama's promise than his performance.