There has been an unmistakable discomfort at including the subject of our dietary choices in the discussion around climate change. Even Al Gore's breakthrough 2006 film, An Inconvenient Truth, overlooks the role our food choices play in an individual's global warming footprint.
Yet when the former vice president accepted the Nobel Peace Prize the year after his film was released, standing beside him in Oslo was his co-recipient, Dr. Rajendra Pachauri, chair of the UN's Intergovernmental Panel on Climate Change and now director of Yale's Climate and Energy Institute. Pachauri has stated repeatedly that for "immediacy of action" dietary change is a person's most doable option for cutting greenhouse gas emissions.
It's not just your mode of transportation, or how well you insulate your home. Now your menu matters, too.
Of course, anyone who has struggled with weight control knows that changing diet can be hard. It runs up against deep patterns established in childhood, the deluge of seductive food industry advertising today, unhealthful choices at restaurants, and all the addictive flavor experiences engineered by tastebud scientists.
But considering the stakes for our planet, the idea of shifting our diet is finally seeping into mainstream thinking about the climate crisis. Leading environmental organizations are also beginning to face this dimension of the problem.
"It's easier to talk about a light bulb than to talk about diet," Dr. Roni Neff told me at her office at the Johns Hopkins school of public health in Baltimore. "But we need to talk about diet, and we need to realize that if that's where we can make our impact, then that's what people need to know."
What we choose to eat relates to climate change because of the enormous invisible plume of heat-trapping gases generated by modern agriculture. In particular, factory farming methods -- which produce the vast majority of foods Americans consume -- are a huge and notably filthy source of global warming pollution. And this matters now, in the wake of 900 mile-wide Hurricane Sandy and in the aftermath of 2012, the hottest year ever.
As a public radio documentary-maker, with a long-standing interest in diet and health, my journalistic antennae rose up several years ago when I began to learn about how the foods we eat affect our planet's atmosphere. The result was our recent Humankind documentary series, The Diet-Climate Connection, which you can hear at http://www.humanmedia.org/dcc/.
Along with millions of others, I had read Frances Moore Lappe's visionary 1971 book, Diet for a Small Planet. It introduced us to the consequences of a meat-centered diet: the squandering of precious food resources in a world where billions go hungry. The amber waves of grain raised today by agribusiness and the oceans of water required to grow them mostly feed livestock, not humans.
It takes about 30 pounds of corn and soybeans to grow one pound of boneless beef (not to mention thousands of gallons of water). That's a lot of inefficiency in our insatiable quest for the fast-food burger.
But just as troubling are the global warming emissions from this hot pursuit. Consider the forests that naturally remove massive quantities of carbon from the atmosphere, but that we cut -- and sometimes burn -- down to grow crops for cows. And all of the fossil-based fertilizers required to cultivate those crops. And then there's the indelicate subject of "manure lagoons" at factory farms, a foul monument to human waste produced by animal waste. These and other impacts of our food system add up big-time. Various studies put it at between about a fifth and a third of all greenhouse emissions.
But there was another aspect of this story that really caught my journalistic attention. The food recommendations made by many climate scientists align neatly with what health experts have told us for many decades: on average Americans consume way too few fruits, vegetables, legumes and grains and far too many meat and dairy products (see: epidemics of obesity, heart disease and diabetes).
What hit me here was the two-fer: what's good for the planet is good for your body.
But where to start? The proportion of Americans who consider themselves vegetarian has remained 4 percent for decades. So urging people to adopt a strictly meatless diet, while very likely the best option for environmental and medical reasons, would be uphill. Look at how many people still use tobacco, decades after medical science reached solid agreement on the dangers of smoking. But a 2011 Harris Interactive poll contained an interesting finding: fully a third of Americans are now eating meatlessly at many or most of their meals. For the majority of us, a more climate-friendly diet will simply mean eating more scrumptious plant-based meals.
Our documentary provides a fascinating echo of history that may be relevant now: "The Meatless Tuesday is working out very satisfactorily in New York City and other cities are adopting it. People of this country must realize that we will have to be more prudent, as we go along in the use of food." That 1944 exhortation came from New York Mayor Fiorella LaGuardia. His mission then was not to stave off climate calamity, but to make sure that American troops had enough meat in WW2.
Today, the weekly meatless observance has shifted to Monday and taken on a distinctly green tinge. Paul McCartney wrote a song, "Meat-Free Monday", heard in our program. Meatless Mondays have been adopted in U.S. public school districts from Baltimore to Oakland, and at many college campuses intent on offering sustainable dining options. The easiest way to reduce your "foodprint" is to waste less food. Eating locally and organically are also climate-friendly. And don't worry too much about protein requirements. There are plenty of delicious bean dishes that will more than do the trick for yourself and for your planet.
For health reasons, Bill Clinton is now a vegetarian. What about his former VP? Al Gore stated in 2011 that "industrial agriculture" and "the shift toward a more meat-intensive diet" are part of the climate problem.