Environmental Engineering Reference
frozen french fries
0 2 4 6 8 0 2 4 6 8 0 2 4
kg greenhouse gas emissions per kg food product
Figure 3.10 Greenhouse gas emissions converted into carbon dioxide equivalents for
the production of different foodstuffs. Data: (Fritsche and Eberle, 2007).
other greenhouse gases such as methane and nitrous oxide and converts these values
into carbon dioxide equivalents according to how harmful they are to the environ-
ment. Beef, butter and cheese do not come out favourably. Ruminant cows release
large amounts of methane that have a high greenhouse effect. Subsequent freezing
of the meat also adds to the energy toll, so that people who prefer frozen meat to
fresh meat increase greenhouse gas emissions by another 10 to 30%.
The amount of processing that food requires also has a considerable effect on the
climate. For example, fresh potatoes hardly tip the scales of greenhouse gas emis-
sion. However, the energy-intensive further processing required to make frozen
French fries increases the greenhouse gas emissions contained per kilogram of food
almost 30 times.
As women normally eat less than men and older people eat less than young people,
clear differences exist from person to person. Going on a permanent diet is certainly
not the right approach to reducing carbon dioxide emissions. However, people who
buy seasonal products from local organic farms, reduce their consumption of meat
and largely avoid tinned and frozen foods can signifi cantly reduce emissions resulting
from food intake. Reductions of up to 30% can easily be achieved this way. However,
those who need a large number of calories because they do a lot of physical work or
sport, and then obtain these calories mainly from frozen products and fast foods,
could fi nd they double their greenhouse gas emissions just from what they eat.
Personal consumption is responsible for around 2 to 3 tons of carbon dioxide. This
is mostly from the production, storage and transport of all products that do not fall
under the category of food supply. Included in this group are clothing, furniture,
machines and equipment, paper products, cars and housing.