Bill Gates has spent years and billions of dollars fighting climate change. The billionaire's foundation has invested huge sums in various climate technology solutions, regularly drawing attention to major contributors to climate change, such as greenhouse gas emissions from large energy and manufacturing companies burning fossil fuels at breakneck speeds. But according to Gates, most people are still unaware of the role played by one of the biggest contributors to climate change: agriculture, specifically methane emissions from livestock and fertilizers. "Of all the climates, people are probably the least aware of all the fertilizers and cows, and that's the challenge," Gates said recently on the latest episode of his "Unconfuse Me" podcast. The topic came up because Gates was in conversation with musician and director Ahmir "Questlove" Thompson, who, like Gates, is an early investor in several plant-based food startups, such as Impossible and NotCo. ((Tom Huddleston Jr.)