If you've spent five minutes in the aisles at M&S,
you'll know that organic food is big business. 'It's better for the environment' claim the marketers, 'It's healthier' and 'think of all those poor animals'. But
is it worth splashing extra cash on organic? What would happen if everyone
decided it was?
It's worth giving a little thought to the
huge benefits industrial agriculture has brought to the world. At the turn of
the 20th century, an agricultural apocalypse was looming. ‘unless the
chemistry world manages to turn the nitrogen of the air into fertilizer' German
chemist Karle Engler told the British Association for the Advancement of
Science in 1898 'the western world will starve’.
A few years later Fritz Haber and Carl Bosch
came up with a method for the industrial scale production of ammonia, the basis
of modern fertilisers. It's difficult to overstate the impact of the
Haber-Bosch process. Since 1950 the relative abundance of cheap food has
allowed global populations to expand from 2.5 billion to today's seven. Without
it, you probably wouldn't be here reading this article.
But intensive agriculture has many side
effects. Fertilisers and pesticides can contaminate hydrological and ecosystems
in unexpected ways. It is here that organic agriculture, with its reduced
reliance on chemicals has clear advantages. You might have also seen claims
that organic food is healthier. But extensive studies have found that organic food offers no
additional nutritional value. And whilst it might expose you to less
pesticides, the levels of pesticides permissible in our food in the UK are so tightly
controlled, they pose no measurable risk to health.
Now remember - this blog is about climate
change! So does organic food produce fewer greenhouse gases? The evidence is often
conflicting but overall the balance seems to point to yes. Nitrate fertilisers
used in industrial farming are broken down by bacteria in the soil, which
release nitrous oxides into the atmosphere. And the techniques used in organic
farming mean that carbon is held, or sequestered, in the soil for longer,
keeping it out of the atmosphere.
Comparing emissions across types of agriculture
is tricky. Different values are arrived at depending on whether you're calculating
emissions per kg of produce or per hectare of land. And figures vary wildly
depending on whether you've accounted for the sequestration effects of organic
farming or not.
An eight year study
by scientists at Michigan State University to measure gas fluxes from agriculture
found that, once sequestration effects were taken into account, emissions from
organic were 64% lower. Modelling
studies show similar reductions. So, if we take the most optimistic
predictions, emissions from agriculture could reduce by 64% if we all ate
organic (or about 9% of total emissions). But this is likely to be a long way off
the actual figure. Far more research is needed to establish the true impact of
going organic.
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| Comparison of soil carbon gains and losses in different farming systems in long term field experiments Source: Low Greenhouse Gas Agriculture, FAO (2009) |
What is clear is that the social implications
would be huge. The reduced yields of organic compared to industrial farming
mean it's unclear
whether it's even possible to feed the global population entirely on organic.
And food prices would undoubtedly rise. In a world where nearly a billion
people go hungry, I think we're best sticking to industrial practices for
the foreseeable future.
