Johnno: Ruby, Happy World Vegan Day! I made you this cake. 

Ruby: Thanks, Johnno. It's, um, definitely vegan. 

Vegans can be hard to cook for. Like vegetarians, they don't eat meat. But they also rule out other animal products, like eggs, milk and sometimes even honey. 

There are different reasons people choose to be vegan, like animal welfare or as a way to eat healthier.

But there's another reason that's been getting a lot of attention recently. Last month, a big study came out looking into the effect our food has on the environment. And it found that eating less meat is one of the most important things we can do to help the planet. 

You see, a huge amount of the earth's resources go into raising livestock for meat. In some places, forests are cleared to make space for animals and to grow their food. They also use a lot of water. And these ones in particular create a lot of carbon emissions. Cow burps and farts account for about 16 per cent of global greenhouse gas emissions. The study says, to prevent permanent damage to our planet, the average world citizen needs to eat 75 per cent less beef, 90 per cent less pork and 50 per cent fewer eggs. 

Of course, not everyone's going to go vegan or give up eating meat completely. But swapping your beef for beans or your chicken for chickpeas every so often might not be such a bad idea. 

Ruby: All right, Johnno, try this.

Johnno: Mmm. This is vegan? 

Ruby: Yeah. It's not all rabbit food.