Bill Gates has started beef with beef, suggesting in an interview that wealthy countries should only eat synthetic beef for the sake of the planet. Gates seemed to be aware of how controversial this statement would be, commenting that “saying to people, “You can’t have cows anymore”—talk about a politically unpopular approach to things.”

Gates – who has a net worth of $137 billion as of February 17, 2021, and is number four on the Forbes Real-Time Billionaires List – published a book titled How to Avoid a Climate Disaster on February 16. The description of the book states that “Bill Gates sets out a wide-ranging, practical - and accessible - plan for how the world can get to zero greenhouse gas emissions in time to avoid a climate catastrophe.”

Speaking to MIT Technology Review in an interview about the new book, Gates was asked how hopeful he was about the future reduction of emissions from agriculture. “In terms of livestock, it’s very difficult,” he replied. “I’m afraid the synthetic [protein alternatives like plant-based burgers] will be required for at least the beef thing.”

When asked whether plant-based and lab-grown meat could be adopted globally as an environmentally-friendly form of protein, Gates stated that the approach could be different in rich and poor countries. “For Africa and other poor countries, we’ll have to use animal genetics to dramatically raise the amount of beef per emissions for them. Weirdly, the US livestock, because they’re so productive, the emissions per pound of beef are dramatically less than emissions per pound in Africa,” he said.

“So no, I don’t think the poorest 80 countries will be eating synthetic meat. I do think all rich countries should move to 100% synthetic beef. You can get used to the taste difference, and the claim is they’re going to make it taste even better over time. Eventually, that green premium is modest enough that you can sort of change the [behavior of] people or use regulation to totally shift the demand.”

It is important to note that Bill Gates is the chair of the investment fund Breakthrough Energy Ventures, and has invested in companies such as Beyond Meats and Impossible Foods either personally or through this fund. However, Gates is backed up by research, with previous studies suggesting a less meaty and more plant-based diet – especially one low in red meat – should be adopted to reduce greenhouse gas emissions and slow the progress of climate change.