Cow burps and flatulence are big news.

Or at least they should be. It turns out that livestock produce more greenhouse-gas emissions than all transportation combined! Ride a bike but love your cheeseburgers? You’re on par with a vegan driving a Hummer.

The environmental impact of our food choices has too often been treated as taboo by all parties, environmentalists among them. Politicians, too, dodge the issue, knowing that careers have been destroyed when the vested interests of various agricultural lobbies, and particularly the beef industry, have been threatened. The problem is real, however. A 2006 United Nations Food and Agriculture Organization report titled Livestock’s Long Shadow illustrates this. While livestock give off only 9 percent of human-caused carbon dioxide, they give off 37 percent of human-caused methane and 65 percent of nitrous oxide. Methane has 23 times the global-warming potential of carbon dioxide, while nitrous oxide (a.k.a. laughing gas) has a whopping 296 times the warming potential! That’s no laughing matter. The methane is mostly a product of the aforementioned burps and farts (“enteric fermentation” and “flatulence,” if you prefer), while nitrous oxide is mostly emitted from manure sitting in storage.

A 2006 study out of the University of Chicago found that the average American diet produces an extra 1.5 tons of carbon dioxide per person per year over a vegetarian diet, which includes eggs and dairy. The researchers also found that not all meats are created equal. It was shocking to see that a fish-centered diet tied a red-meat diet as being the worst for the planet because of the energy expended during capture and transport of fish. Of course, as we live in California, our transport distance is much less than in many other areas, so the impact may well be smaller than calculated. Nonetheless, the finding that a diet with poultry rather than other meats was the second-best choice is worth serious consideration. Researcher Gidon Eshel summarizes the findings: “We say that however close you can be to a vegan diet and further from the mean American diet, the better you are for the planet. It doesn’t have to be all the way to the extreme end of vegan. If you simply cut down from two burgers a week to one, you’ve already made a substantial difference.”

Just so you know where I’m coming from, I should tell you that I eat meat, eggs, and butter and drink milk, so nothing is entirely off the table for me just yet. But I eat beef or pork only very rarely. I do not consume dairy milk or butter very often. I am working to reduce my consumption of cheese and eggs. When I eat meat, it tends to be chicken or turkey. This is a great change from what I used to consume: lots of beef and milk, and more butter, pork, and eggs than I do now. So I’m moving, if very gradually, in a direction that’s good for our environment and my health. If I can do it, you probably can, too.

To conclude, the best thing for the planet is to go vegan. Such a diet minimizes your contribution to climate change and has other benefits as well. You won’t have antibiotics or hormones in your food. Much less water will go into the production of your food. Fewer forests will be cut down to make room to grow your food. Less nitrogen and phosphorous will get dumped into your fresh water. Your food won’t overgraze and erode valuable soils. And on and on. The next-best option: Eat meat and animal products only infrequently (one to three meals per week), choosing poultry over red meat whenever possible. And finally, the easy-way-to-make-a-major-change option: Start by eating a little less of those products than you do now, and continue to cut back gradually on a week-to-week basis. Keep track (as in, write it down) or else you won’t really do it. In the end, your heart and the planet will be grateful.