Greenberg has written about food and the environment for years. He’s best known for his 2010 book Four Fish, which explored commercial fishing. For his new book, he asked dozens of experts, “If you’re going to make a choice in your particular field to do the best thing for the environment, what would it be?” The answers he got allowed him to design this roadmap for an average person, and his suggestions aren’t that hard to implement. You don’t have to go vegan (though it’s a good idea) and you don’t have to move into an off-grid yurt. You can dramatically reduce your carbon footprint with lots of little things, like cutting beef out of your diet or using an electric stove instead of gas.