Here's another eco-biggie: methane, emitted from both ends of these ruminants. Incredibly, the EPA rates their belchings as the third-largest methane source behind landfills and natural gas systems.
A greenhouse gas, methane has 20 times the global warming effect of carbon dioxide.
OK, what if I also have a helping of exquisitely green broccoli, locally grown?
Weber, a vegetarian, thwarts me again. The real meat of his study is that eating local doesn't make up for eating beef.
Swell. Now that advocates have gotten us to replace asparagus from Peru with spinach from a nearby farm, he's gone and found that transportation represents only 11 percent of the emissions made in producing the American diet.
Looking at the "life cycle" of food production, he says red meat and dairy products - it's the methane again, plus fertilizer, tractors and manure - account for 48 percent of emissions from making our food.
He says shifting one day per week's worth of calories from red meat and dairy to chicken, fish, eggs or, better yet, veggies, will reduce emissions more than buying all locally sourced food.
It's not the miles, it's the meat.
Well, then I guess I can have rice, even though my favorite brown basmati is from Texas.
I really don't want to eschew beef, so I call the National Cattlemen's Beef Association for help. They hook me up with Penn State animal scientist Bill Henning.
He can't exactly comfort me with studies showing beef is more eco-friendly than vegetables, but he diligently lists beef production advances that have trimmed emissions.
The association also touts "sustainability fun facts," noting that ranchland has been restored for the grizzly and that grazing reduces the risk of wildfire. Not the spirited defense I was seeking.
For the sin of my steak, what if I forgo dessert, and donate my sugarcane to ethanol?
In the end, it's Larry Herr, one of several area farmers raising grass-fed cattle, who just might save my beef.
Without corn, the beef is leaner, which proponents say has dietary benefits. And a national advocacy Web site, Eat Wild, ascribes myriad eco-virtues to grass-fed beef compared with factory farms, saying pastures reduce topsoil erosion and absorb scads of carbon dioxide.
Plus, cattle grazed on grass produce 20 percent less methane. (Weber concurs.)
Herr's 60-acre farm southeast of Lancaster has been in his family for six generations. On his family farms here and in New York he's planted 1,000 trees as stream buffers and hosts a wind generator.
My husband met Herr at - yes! - a Chester County farmers' market at Anselma Mills.
Herr drives 50 miles to get there, but he hopes that once people taste his beef, they'll order bulk for their energy-efficient freezers.
Oy. Food is so complicated. Seems every up has a down.
Seafood has low emissions, but what about overfishing?
And what does the recent salmonella scare in tomatoes tell us about the importance of knowing where your food comes from?
I've decided to practice moderation in everything - including getting worked up about cow gas.
Just the other night, with Herr's steaks sizzling on the grill, a personal connection to the farmer felt so satisfying. Best of all, the delmonicos were delicious.
Contact staff writer Sandy Bauers at 215-854-5147 or firstname.lastname@example.org. To post a comment, visit her blog at http://go.philly.com/greenspace.