New Scientist - USA (2020-03-21)

21 March 2020 | New Scientist | 25

P

EOPLE are keener than
ever to make ethical,
environmentally friendly
food purchases. But a spate of bad
press about the environmental
impact of organic produce may
leave some people scratching
their heads.
The debate about this is
contentious. Critics say organic
farming is less efficient than
conventional farming, and so
uses more land, leading to greater
deforestation, which causes
higher carbon dioxide emissions
and biodiversity loss. A recent
paper followed this logic to find
that going 100 per cent organic in
England and Wales would raise
these emissions by up to 56 per
JOScent. The claim made headlines.

IE^ F

OR

D

Comment

Christel Cederberg is at Chalmers

University of Technology, Sweden, and

Hayo van der Werf is at INRAE, France

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But the findings from this study

and similar ones are too simplistic

and ignore important positive

aspects of organic farming. We

have analysed such studies and

found that the method they often

use doesn’t give the full picture.

Known as a life cycle assessment

(LCA), this approach simply relates

environmental impacts to the

amount of product harvested from

a given area of land. Looked at this

way, intensive farming is often

more efficient, since its yields are

higher. But this doesn’t properly

address all environmental aspects.

Such assessments fail to

fully account for the role of

land degradation, biodiversity

decline and pesticide impacts

of intensive agriculture.

Consider biodiversity, for

example. The variety of life on

Earth is an incredibly important

factor in the health and resilience

of ecosystems. But worldwide,

it is in decline – insect and bird

populations are being decimated,

something that has been

repeatedly linked to the damaging

practices of intensive farming.

Organically managed land,

however, has been shown to

support biodiversity levels

around 30 per cent higher than

conventionally farmed fields.

It might be argued that the

land saved through conventional

farming could be reserved for

biodiversity and CO2 absorption.

But the relationship between

agricultural intensification and

reduced deforestation is unclear.

In Brazil, for example, agricultural

intensification has coincided with

more deforestation.

Widespread use of pesticides

is also a concern – between 1990

and 2015, global pesticide use

has increased more than 70 per

cent. Pesticide residues can be

harmful to land and aquatic

ecosystems, as well as our health.

The avoidance of synthetic

pesticides in organic farming, and

the overall much lower levels of

pesticide use in general, is a factor

that is often overlooked in LCAs. In

the 34 studies comparing organic

with conventional agriculture

that we reviewed, only nine looked

at pesticide-related impacts.

The debate around the

environmental impact of organic

farming has become too simplistic

and narrow. Our review, published

in Nature Sustainability, shows

that organic farming’s strengths

and environmental benefits are

often overlooked by the current

research, and simply claiming that

organic farming is worse for the

environment is misleading.

The current use of LCAs needs to

be improved and integrated with

other environmental assessment

tools. Only then will consumers

get a more balanced picture. ❚

In defence of organic food

Claims that organic farming is worse for the environment are too

simplistic, say Christel Cederberg and Hayo van der Werf