At Brown's urging, scientists from more than 40 countries have signed a 20-page consensus statement asking policy makers -and the public- to combat climate change.
It identifies and offers solutions to five global problems.
They include climate disruption, species extinctions, loss of ecosystems, pollution and population growth.
Governor Brown touted California's accomplishments while speaking at NASA Ames Research Center.
"We are in the forefront, there is no political jurisdiction doing more about climate change than the state of California," says Brown. "We're going to continue to do that and to the extent possible we're going to engage others in other states including Washington and whoever else we can find."
Brown told a room packed with scientists that climate change is no longer about science, but about activism.