By Dharna Noor for The Real News Network - DHARNA NOOR: Welcome to The Real News Network. I'm Dharna Noor joining you from Baltimore. There's a growing awareness that meat production puts a strain on water, land use and habitats, and that it increases greenhouse gas emissions, which drives climate change. But few know the largest environmental impact actually comes from what the animals are being fed. To discuss a recent study on this topic, it's from the UK branch of the World Wildlife Fund, and it's titled Appetite for Destruction. We're joined by Duncan Williamson. He's the food policy manager for WWF UK. Thanks for joining us today, Duncan. D. WILLIAMSON: Well, thank you very much for having me. DHARNA NOOR: So, your recent report says that producing crops to feed livestock is putting an enormous strain on our natural resources, and it's a driving force behind wide scale biodiversity loss. How does livestock feed actually have that kind of impact? D. WILLIAMSON: It's two things. It's the numbers of animals that we're producing globally, and where we are growing the crops to feed them, so for example, we know there's 23 billion poultry animals on the world at the moment. That's enough for three animals each basically, and most of these animals are grown in intensive systems, so they don't have access to the outside, so they have to be fed on something, and their feed tends to be maize and soy.