Caro _etal _Fig1

A lot of the meat we eat is produced in a different
country from the one we live in. A new study finds that greenhouse
gas emissions from the beef, pork and chicken traded across borders
have risen by 19 per cent in the past 20 years.

Not only might this affect diets of the
climate-conscious, but a trend towards eating meat produced in a
different country could make monitoring countries’ individual
emissions a far trickier task, say the researchers.

Livestock emissions

Carbon dioxide is the biggest contributor to climate
change, but other greenhouse gases such as
nitrous oxide
play a role too. The methane and nitrous
oxide produced by livestock, such as cows, pigs and chickens,
account for around nine per cent of all greenhouse gases emitted

When you include methane and nitrous oxide emissions from
transporting the animals and producing their feed, this proportion
rises to 18 per cent.

A new study, published in Environmental
Research Letters
, finds that although the majority of meat is
eaten in the country where it’s produced, more and more meat is
being exported.

So which country should be held responsible for the
greenhouse gas emissions? The one where the meat is produced or the
one where it’s consumed?

The researchers say the growing demand for
internationally-traded meat makes it harder to regulate emissions
from farming.

Emissions from trade slipping through the

All existing national or international policies to limit
greenhouse gases take account of emissions from within specific
countries only. So if the UK imports a tonne of beef, for example,
the greenhouse gas emissions from producing it are not counted in
our inventory.

You might think the emissions would be counted by the
country producing the beef, but that might not be the case. The
researchers say it’s increasingly likely that meat is being
imported from developing and emerging nations, which often have
less stringent accounting of greenhouse emissions.

So the emissions from that tonne of beef may not be
counted by either country, and instead may just ‘leak’ between the
gaps in the system, say the researchers.

Beef the worst emitter, but others are
catching up

Of the meat traded from one country to another, the
study finds beef makes the biggest contribution to emissions,
responsible for around three-quarters of the GHGs produced.

The research takes account of methane produced as
livestock digest food (yes, farting) and the methane and nitrous
oxide released as manure decomposes.

Emissions from traded pork (20 per cent) and chicken (six per
cent) production are much lower by comparison, but are growing much
more quickly. Between 1990 to 2010, the emissions from traded beef
grew by around four per cent, while those from pork and chicken
grew by 81 per cent and 360 per cent, respectively. You can see
this in the charts below.

Emissions of methane and nitrous oxide from
livestock in production of A) beef, B) pork and C) chicken. Graphs
show total emissions per year (blue line) and emissions from traded
meat (red line) in million tonnes of carbon dioxide equivalent.
Caro et al. (2014)

Where does the traded meat go?

The researchers worked out which countries are responsible for
the most emissions by mapping where meat is traded from and to.

The map below shows the main flows of livestock
emissions around the world. You can see Russia (red) imports large
amounts of meat from Brazil (yellow) and Argentina


Map of the largest emission imports and exports
from meat production in 2010. Arrows show total emissions per year
in million tonnes of carbon dioxide equivalent. Caro et al. (2014)

Emissions from meat traded within Europe are
shown in the map below. Italy (green), for example, consumes a lot
of meat produced elsewhere, particularly France (yellow) and Poland
(beige). That means around a third of methane and nitrous oxide
emissions from meat consumed in Italy in 2010 were produced in
another country.

Screenshot 2014-11-14 13.50.30

Map of the largest European emission imports and exports
from meat production in 2010. Arrows show total emissions per year
in million tonnes of carbon dioxide equivalent. Caro et al. (2014)

Emissions hidden in traded meat could even
encourage countries to import meat rather than produce it
themselves, warn the authors. This new research highlights the risk
that greenhouse gas emissions from meat production could be
overlooked completely as global trade increases, complicating
attempts to reduce emissions from farming.

Caro, D. et al. (2014) CH4 and N2O emissions embodied in
international trade of meat, Environmental Research Letters, doi:10.1088/1748-9326/9/11/114005