A speaker at the World Economic Forum (WEF) called on one billion people to "stop eating meat" to combat climate change. 

"If a billion people stop eating meat, I tell you, it has a big impact. Not only does it have a big impact on the current food system, but it will also inspire innovation of food systems," Siemens AG Chairman Jim Hagemann told the WEF crowd in Davos, Switzerland, on Wednesday.