I'm continuing the food theme for this latest post. Maybe
it's my love of eating; or maybe it's because the more I read into it, the more
fascinating the carbon economics of food seem to be. This time round it's the
local food movement. We should all buy locally, right? Well, what would happen
if we did?
You're probably familiar with the concept of food miles -
the distance our food travels before it reaches our supermarket shelves.
Transporting goods causes greenhouse gas emissions. Reduce your food miles, the
theory goes, and reduce emissions from your food. And when 14% of global
emissions come from agriculture, there's big savings to be made!
If you've read any of my previous posts, you'll know that
things in the world of emissions are never as simple as they first appear. Take
the case of Young's, who got in trouble a few years back when it was revealed
their locally
sourced Scottish prawns where flown to Thailand for shelling before returning
to the UK to be sold in our supermarkets. Customers thinking they were buying local
produce were unsuspectingly buying a product with 12,000 embedded food miles!
Luckily studies have shown that it's not food miles that
count - the methods used to grow your food are much more important. It's
helpful here to have a look at a few case studies. Consider the tomato. A 2008
DEFRA study found that tomatoes grown in the UK were responsible for three
to four times more emissions than those imported from Spain, even when the
additional food miles were taken into account. This is because UK tomatoes tend to be
grown in gas heated greenhouses. A similar study
by New Zealand researchers found British lamb was four times more energy
intensive than New Zealand lamb, even allowing for transport to the UK - due
mainly to the use of larger quantities of fertilisers by UK farmers.
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He may look tasty. But if he's from the UK, his carbon
emissions may be bigger than you think
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All the evidence seems to say that, if you're looking to
reduce emissions from food, you need to look at the entire lifecycle of
the foods you eat. If you do that, as these American researchers
did, you'll find that food miles account for only about 11% of emissions
from our food. Even more scarily, a
study by the University of California looked at what would happen if
everyone in their local area of Santa Barbara County bought locally.
Amazingly they found it would reduce emissions from food by less than 1%!
So there you have it. If we all ate locally, the impact on
food emissions might be as low as one percent!
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Tesco now put carbon footprints on products to help
consumers make informed choices
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So what should you buy? Well in his excellent book How bad are bananas? author Mike
Berners-Lee says you
can't go wrong with a banana. Good advice if you ask me. Imagine the
detrimental impacts to countries like Ecuador - where 61% of the agriculturalGDP comes from banana exports - if we all stopped eating bananas. When you
start looking at situations like this, you can see the issue of buying locally
extends far beyond just carbon emissions.
If you want more about food miles, the ever brilliant
Freakonomics team have produced this excellent podcast. In it they speak to the
authors of the Santa Barbara county study.
