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concerns about animal welfare, medical experts
have long encouraged people to eat less processed
and red meat for health reasons (SN: 11/28/15, p. 9).
What is becoming crystal clear is that a meat-heavy
diet is also terrible for the planet (SN: 7/7/18, p. 10).
Shifting demand from meat to beans, whole
grains, fruits, vegetables, nuts and seeds could have
substantial benefits for the climate. In 2018, total
greenhouse gas emissions worldwide were almost
49 billion metric tons. That same year, the United
Nations Intergovernmental Panel on Climate
Change, the IPCC, estimated that if everyone in the
world went vegan, eating only plant-based foods,
global emissions could drop by roughly 16 percent
in a year, or 8 billion tons.
Meanwhile, going vegetarian, a plant-based
diet that includes dairy, eggs and the very occa-
sional meat or seafood allowed in IPCC’s definition,
resulted in a 6-billion-ton drop. For those reluc-
tant to give up the bacon entirely, the IPCC says
a less absolutist approach could still reap big
benefits. The panel estimates that a flexitarian
diet — reducing meat and dairy consumption by
75 percent — could cut emissions by 5 billion tons.
Individual behavior changes alone cannot fix a
supply chain built around the mass production of
meat and animal products. But a more recent April
report from the IPCC (see Page 8) suggests that the
world’s wealthiest individuals could substantially
decrease emissions through lifestyle changes, such
as driving and flying less and eating less meat. That’s
because households with incomes in the top 10 per-
cent generate roughly 36 to 45 percent of global
emissions, while households with incomes in the
bottom 50 percent contribute just 13 to 15 percent.
Moreover, wealthier individuals serve as role mod-
els. So those who adopt a low-carbon lifestyle can
help establish new, more sustainable social norms.
Social norms are unwritten rules for how to
behave in a given group. Norms encourage con-
formity. If everyone in a group wears clothes, a
single member is unlikely to wander outside naked.
But if people think that shedding one’s clothing is
becoming the new norm, can this encourage oth-
ers to follow suit? Yes, Sparkman says. “Actions you
do ... ripple outward and can change others.”
The challenge, he and others say, is sorting out
how to encourage that snowball effect to transform
really strong social norms, such as eating meat.
These scientists are, in a sense, trying to under-
stand how to make the abnormal appear normal.
What would it take, for instance, for people to
mentally swap Rockwell’s Thanksgiving turkey for
something greener?Changing normal
Social norms, which by design remain relatively
stable across time, typically hinder social change.
But research shows that people conform not just to
present norms but also to perceived future norms,
what Sparkman calls “preconformity.” That sug-
gests that reframing the Julie Babulskis among us
as trend setters rather than social deviants could
encourage others to conform to their plant-based
vision of the future (SN: 2/26/22, p. 24).
In that vein, Sparkman and colleagues have been
testing whether giving information on changing, or
“dynamic,” norms can shift people’s food choices. In a
pilot study, the team surveyed café-goers at Stanford
University. When the 304 mostly faculty, staff and
graduate students were waiting to order, research-
ers handed them one of three written statements.
Some participants received a static norm mes-
sage: “Recent research has shown that 30 percent
of Americans make an effort to limit their meatEye to the future
Café-goers who read that
meat-eating is decreasing
over time, the dynamic norm
group, were more likely to
order a vegetarian meal
than those who read that
some Americans limit their
meat intake, a static norm,
and the controls, who got an
irrelevant message.
SOURCE: G. SPARKMAN AND
G.M. WALTON/PSYCHOLOGICAL
SCIENCE 2017A meat-heavy diet is the norm in the United States, as this billboard in Ozark, Mo.,
shows. To reduce greenhouse gas emissions, researchers are trying to figure out how
to get people to buck the norm and go for a diet that’s richer in plants and beans.Messaging affects meatless lunch ordersConditionPercent who ordered a meatless lunchControl Static norm Dynamic norm403020100