Billionaire environmentalist Tom Steyer addresses a crowd in Saint-Denis, Paris on Dec. 8, 2015.
Billionaire environmentalist Tom Steyer addresses a crowd in Saint-Denis, Paris on Dec. 8, 2015. dsiders@sacbee.com The Sacramento Bee/David Siders
Billionaire environmentalist Tom Steyer addresses a crowd in Saint-Denis, Paris on Dec. 8, 2015. dsiders@sacbee.com The Sacramento Bee/David Siders