California Governor Jerry Brown is joining more than 500 scientists from 40 countries in calling for action on climate change.
A 20-page consensus statement signed by scientists identifies five threats to the planet that policy makers need to address. They include climate disruption, species extinction, loss of diverse ecosystems, pollution and population growth.
Speaking at NASA Ames Research Center, Governor Brown said climate change is no longer just about science, but about activism.
"This is an important challenge cause undertaking," Brown said. "We're here, we're going to take any steps we need but we can do it, but we got to do a lot more than what we're doing now."
He challenged scientists to be "change agents." He also credited California for having done more about climate change than any other state.
