1UTS Business School, University of Technology Sydney, Ultimo, New South Wales, Australia. 2Fuqua School of Business, Duke University, Durham, NC,
USA. 3Duke University School of Law, Duke University, Durham, NC, USA. 4Nicholas School of the Environment, Duke University, Durham, NC, USA.
There is a widespread scientific consensus regarding the
urgency to reduce GHG emissions1, and on the need to study
alternative interventions to do so. Much research has empha-
sized technological solutions such as greater energy efficiency and
increased use of renewable sources of energy2. More recently, it has
been recognized that diet change is also a potential solution worth
exploring3–5. Economic analysis has examined the virtues of mar-
ket-based mechanisms to influence demand, such as a carbon tax
that increases prices in line with social costs6. Increasingly, however,
social scientists have turned their attention to possible behavioural
interventions to influence demand7. For example, social psychologi-
cal research on social norms shows their effectiveness in producing
behaviour change in some contexts8,9. However, social norms are
problematic when the desired behaviour is rare10. Another interven-
tion approach is to ‘boost’ consumer decision-making by providing
relevant skills, knowledge and decision tools11. The efficacy of such
boosts requires first understanding the relevant knowledge gaps.
Attempts to modify behaviour typically presume that con-
sumers recognize the connection between their acts and the
consequences for energy consumption and GHG emissions12,13.
However, there is a growing body of research demonstrating
that consumers are often unaware or misinformed. For example,
Attari, et al.14 found that people had a rudimentary understanding
of the relative energy use of different electrical household appli-
ances (henceforth, appliances) and activities. On average, people
correctly recognized that refrigerators used more electricity than
light bulbs, but were insensitive to the true difference between
relatively high- and low-emitting appliances.
Research suggests that the food system contributes 19%–29%
of global GHG emissions15, which is similar to emissions from
US household electricity use16. Many factors combine to produce
such considerable emissions. Agriculture is highly industrialized.
Refrigeration and transportation tend to depend heavily on fos-
sil fuels. Natural gas is a key input in the manufacture of fertil-
izer. Cattle raised for beef and dairy products are major sources
of methane. Moreover, the process of raising meat is inherently
inefficient: fertilizer is used to grow feedstock, but only a small
portion of the feed becomes animal protein; the rest becomes
manure and methane. Thus, it takes 38 kg of plant-based protein
inputs to produce 1 kg of edible beef17. Finally, in many parts of
the world, burning forests to create grazing and agricultural land
also emits GHG emissions. A significant reduction in GHG emis-
sions from food could be achieved by changing consumers’ diet; in
particular, by moving toward more vegetarian or vegan meals18,19.
Even changing the type of meat consumed could have a large ben-
eficial environmental impact20.
Existing research, which typically asks consumers via survey
to indicate knowledge or agreement with facts about the environ-
mental impact of food, suggests that consumer awareness of the
environmental impact of meat production is low21–24. Importantly,
however, those who believe that reducing meat consumption effec-
tively reduces GHG emissions are much more likely to intend to
reduce eating meat22,25.
Understanding consumersʼ perceptions of energy consump-
tion and GHG emissions of individual food items in a way similar
to Attari et al.14 is important because it can inform the design of
information interventions to help consumers understand the true
impact of their behaviours. Experimental studies investigating sim-
ple interventions to increase pro-environmental food consumption
behaviour have yielded only modest results26. Therefore, additional
research that identifies effective ‘boosts’ is needed.
One of the most straightforward ways to attempt to influence
food choice is through labels27. For example, a carbon label com-
municates information about the total amount of GHG emissions
from within a defined supply chain (for example, from cradle
to grave). Carbon labels provide information to consumers that
can be factored into purchase choices and also exert pressure on
manufacturers and retailers to provide consumers with lower-
The research associated with environmental labels on foods
is mixed. Some research suggests that consumers desire carbon
labels29,30. However, other research suggests that consumers barely
use environmental labels when making food choices31. Still other
research indicates that environmental labels can move consumption
Consumers underestimate the emissions
associated with food but are aided by labels
AdrianR.Camilleri 1*, RichardP.Larrick2, ShajutiHossain3 and DaliaPatino-Echeverri4
Food production is a major cause of energy use and GHG emissions, and therefore diet change is an important behavioural
strategy for reducing associated environmental impacts. However, a severe obstacle to diet change may be consumers’ under-
estimation of the environmental impacts of different types of food. Here we show that energy consumption and GHG emission
estimates are significantly underestimated for foods, suggesting a possible blind spot suitable for intervention. In a second
study, we find that providing consumers with information regarding the GHG emissions associated with the life cycle of food,
presented in terms of a familiar reference unit (light-bulb minutes), shifts their actual purchase choices away from higher-
emission options. Thus, although consumers’ poor understanding of the food system is a barrier to reducing energy use and
GHG emissions, it also represents a promising area for simple interventions such as a well-designed carbon label.
NATURE CLIMATE CHANGE | VOL 9 | JANUARY 2019 | 53–58 | www.nature.com/natureclimatechange 53
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