Carbon footprint of products to be displayed on label package
The first product to be stamped with the logo will be Walkers cheese and onion
crisps. The Carbon Trust has enabled Walkers to identify the footprint of the
3 competing products in its range – crisps, Quavers and Doritos – by tracing its
production cycle from the potato and corn producers at the start to recycling
consultants at the end. As a result, Walkers has reduced the carbon footprint
of the product by a third. By changing the way potatoes are traded, the trust
found that the Walkers supply chain could save up to 9,200 tons of carbon dioxide
emissions and £1.2m a year. Research undertaken by the trust shows that 66 per
cent of consumers say they want to know the carbon footprint of the products they
buy. (Independent)
Scholz et al. ( 2009 ) report that fresh salmon air freighted
from overseas has about twice the environmental impact as frozen salmon transported
by container ships over the same distance. The difference owing to transport
modes is far more signifi cant in this case than production choices such as wild versus
farmed or organic versus conventional.
page 217
http://www.cleanmetrics.com/pages/Ch9_0923.pdf
If we replace our assumption of long-distance road transport with other distances
and transport modes, the results will change signifi cantly. For example, if air transport
is used to deliver fresh imported foods from distant production locations, transportation
will be a major contributor to the total life cycle emissions, regardless of
production emissions. Ocean transport, on the other hand, generally produces low
transport emissions per unit of freight. For foods that are imported via ocean, the
road transport to and from the sending and receiving ports often generates emissions
comparable to the [much longer] ocean segment, and therefore the total transport
carbon emissions for ocean-related segments are likely to end up being comparable
to the emissions associated with domestic truck transport for long distances.
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see long article at http://researcharchive.lincoln.ac.nz/dspace/bitstream/10182/248/1/aeru_rr_299.pdf
In a study of the relative transport contributions to UK food transport, cars were found to
account for the largest number of food kilometres (48 per cent of total kilometres) although
UK heavy goods vehicles (HGV) operating locally and in Europe were the largest emitters of
carbon dioxide (57 per cent of total CO2 emissions) (AEA Technology, 2005). Air freight
accounted for only a small share of total carbon dioxide emissions (10 per cent). For the
period 1992 to 2002 UK urban food kilometres increased by 27 per cent, HGV food tonne
kilometres increased by 36 per cent, and air freight increased by 140 per cent. These trends
have led to a 12 per cent increase in the CO2 emissions associated with food.
A UK study focusing solely on the transportation of lettuce, apples and cherries found that
UK and Spanish grown lettuces had the lowest CO2 emissions (44-45kg CO2/tonne) (Mason,
Simons, Peckham & Wakeman, 2002). Apples which on average travelled the furthest (8,767
km) emitted 2.4 times more CO2. Cherries which on average travelled 7,751 km emitted the
largest amount of CO2, 80 times more CO2 than for the lettuce. The main factor influencing
the higher CO2 emissions for the cherries was the proportion of the imports air freighted from
North America. In contrast the New Zealand sourced apples were sea freighted and therefore
had lower CO2 emissions. An important observation made in this study was the expert advice
that it would be climatically and economically challenging to increase the UK grown supply
of cherries and lettuce. In the case of apples, this was possible for only limited varieties.
Mason et al.’s observation about the limited opportunity for replacing imported produce is
even more significant when the United Kingdom’s low level of self sufficiency in fruit (9 per
cent) and vegetables (62 per cent) is considered (Garnett, 2006).
Product based LCA studies offer some important perspectives on the relative contribution that
air freight transport makes to the total greenhouse gas emissions associated with fresh fruit
and vegetables. Although air freight is an important contributor to fresh produce CO2
emissions, several studies have found that heated greenhouse production systems, home
cooking methods, and consumer shop to home transport choices can also be significant
contributors to a product’s CO2 emissions. For example, a consumer’s shopping trip of more
than 10 km to solely purchase one kilogram of fresh produce will generate more CO2
emissions than the air freighting of one kilogram from Kenya (van Hauwermeiren, Coene,
Engelen & Mathijs, 2007).