Urban Agriculture, Land Use and
Climate Change
Natasha Eichler
CLIMATE CHANGE
& CITIES
Cities are growing. And as they grow so too
does their demand for housing, transport,
jobs, schools, hospitals and universities;
as well as for the goods and services their
populations need to live and thrive.
We now know that in many ways this
growth has led to human-induced climate
change. Cities now account for more than
70% of global greenhouse gas (“GHG”)
emissions.
INTRODUCTION
With the impending threat of climate
change cities are looking for ways to
reduce their carbon footprint.
Can urban agriculture contribute to a
carbon neutral future, and what role do
urban planners have to play in realising
such an outcome?
This document seeks to summarise
research carried out by a team at Arup,
which explored the extent to which urban
agriculture was an effective use of urban
land for the purposes of reducing a cities
Greenhouse Gas Emissions (GHG).
It explores the topics of climate change,
and the role cities and their food systems
have to play in reducing global GHG’s.
It questions the validity of using scarce
urban land for agricultural purposes,
despite current trends and city and
community enthusiasm to do so.
It concludes by proposing that Arup further
explores the role interacting urban
systems, such as transport, master
Planning and urban design, can pay in
reducing the carbon emissions associated
with feeding our cities.
With the impending threat of climate
change, cities are becoming more cognisant of the need to respond to growth
in a way that reduces or prevents their
emissions of GHG’s.
While countries continue to make incremental progress, cities are recognising
their ability to forge ahead, and lead
efforts which will help meet the Paris
Agreement target of limiting global warming to well below 2 degrees Celsius above
pre-industrial levels.
While countries
continue to make
incremental progress,
cities are recognising
their ability to forge
ahead.
Many cities are now setting their own
ambitious targets and developing
transformational action plans that aim to
put their city on a path to becoming emissions neutral. Many of these plans focus
on increasing the supply of renewable energy, improving building energy efficiency,
increasing access to low carbon transport
options, and promoting higher density,
small footprint, compact living.
One area which has received newfound
attention is the role the food systems of
cities play in climate change.
THE FOOD
NARRATIVE
Today’s food systems, including production, processing, packaging, distribution,
consumption and waste, account for up to
30% of global greenhouse gas emissions.
Food, along with air, water and shelter, is
essential to life. Our daily routines revolve
around it, our health depends on it, our
identity and culture are inseparable from it
and the economy is driven by it.
Alongside this, the development of industrial fertiliser increased yields, and
technological advancements improved
preservation techniques and reduced
transportation costs. This made it economically attractive to remove food production,
along with its perceived health threats
from the urban environment.
Cities today
predominantly meet
their demand for food
through relying on large
scale farming, mass
production lines, and
pre-packaged goods.
The Milan Urban Food
Policy Pact, signed on 15
October 2015 by more
than 100 cities acknowledges that cities have a
“strategic role to play in
developing sustainable
food systems and can
take action to mitigate
GHG emissions through
their urban food systems.”
In responding to this, global climate
change networks and industry groups
By virtue of their population, size and
are beginning to recognise the opportuAs a result, cities today predominantly
wealth, urban areas when compared to
meet their demand for food through relying nity cities have to help alleviate the GHG
rural regions, now consume the majority of on large scale farming, mass production
emissions associated with feeding their
food globally and thus make a significant
populations.
lines, and pre-packaged goods. This procontribution to this environmental burden. cess is typically associated with high rates
of GHG emissions, due to being heavily
Historically, cities have been constructed
reliant on fossil fuels for fertiliser, for the
around the necessity and challenges asso- transportation, refrigeration and packagciated with feeding their populations. But
ing of goods, and for the disposal of high
during the 20th century, urban agriculture volumes of waste products.
disappeared from many cities, and was
replaced with higher density residential
development, aimed at accommodating
increasing urban populations.
FINDINGS
The research revealed that piecemeal evidence is beginning to suggest that urban
environments were more likely to promote
Findings from this review are documented approaches to food production that had
in full in the attached report.
reduced reliance on fossil fuels. However,
in many instances research had only been
In sum the research indicated that while
conducted in relation to one crop, or one
theoretical claims relating to the role urban city, or one method of cultivation or model
agriculture can play in climate change mit- of distribution. This made it difficult to
igation are widespread, empirical evidence draw robust conclusions.
to support these claims were premature
and often speculative.
If urban agriculture is
to be regarded as a
valid use of urban land,
its value must be made
tangible, measurable and
competitive.
URBAN AGRICULTURE
THE RESEARCH
One response which has received considerable traction among urbanists and
city officials is the role urban agriculture
can play in climate change mitigation.
Urban agriculture refers to the growing
and processing of food within an urban
and peri-urban environment, for an urban
market.
In the context of resolving the challenges
associated with growing populations, rising
property prices and worsening congestion,
using urban land for agriculture is not a
conventional approach.
In the context of climate change, this
movement is premised on the benefits of
bringing the consumer closer to the place
of production, having greater agency over
the processes used during cultivation,
reducing packaging, and providing opportunities for the reuse of waste products.
In recent years cities such as Vancouver,
Quito and London (Canada), have begun
to show interest in urban agriculture. The
American Planning Institute called planners to “support a reduction in carbon
emissions through enabling urban agriculture”; while Auckland’s Low Carbon Action
Plan noted that Auckland must “reduce the
greenhouse gas emissions associated with
transporting food over large distances”.
Around the world, community groups have
begun to implement different initiatives
to bring urban agriculture to their cities.
Urban Food Street in Queensland now produces commercial quantities of spray free
fresh fruit, vegetables, herbs and spices on
the street edge.
Urban designers and architects have
begun to experiment with innovative
approaches to master planned communities, which embed the growing of fruit and
vegetables into their design. In South East
Asia, architecture firm Spark is experimenting with building retirement communities
that double as city farms. The design aims
to tackle the issue that most food in the
region is imported, while also providing
meaningful employment for an aging population.
Few cities have implemented urban
agricultural interventions to a scale which
produces appreciable yields able to feed
their populations. If urban agriculture is to
be regarded as a valid use of urban land,
its value must be made tangible, measurable and competitive.
could provide a sound evidence base for
city officials to justify future investment
and land use decisions.
To achieve this a literature review was
undertaken, guided by three central questions:
1) What claims have been made in relation
to the role urban agriculture plays in climate change mitigation?;
2) What quantitative evidence or empirical observations exist to support these
claims?;
3) What limitations, trade-offs and compromises are associated with designing and
While many cities have assumed that
urban agriculture could play a valuable role implementing urban agricultural initiatives
in climate change mitigation, evidence to
to achieve climate change mitigation?
support this has not yet been collated.
A team of researchers from Arup were
inspired to respond to this. Their research
sought to gather evidence relating to the
role urban agriculture could play in climate
change mitigation on the basis that this
Overall, the research identified that any
potential contribution urban agriculture
may make to climate change mitigation
was unlikely to be achieved through small,
grass roots interventions. Instead, what is
required is an aggressive, cohesive, scalable response. However, such an intervention is likely to compromise a cities’ wider
efforts to reduce their carbon emissions.
What is required is an
aggressive, cohesive,
scalable response.
For instance, dedicating large portions
of urban land to agriculture can promote
urban sprawl. This negates the promotion
of compact cities, where GHG emissions
are reduced through enabling shorter
travel distances and making better use of
existing infrastructure.
Additionally, the research identified that
many factors contribute to the amount of
carbon emissions associated with the food
arriving in cities. For instance the research
revealed that the type of cultivation,
fertiliser and machinery used, or the types
of crops grown had a far greater impact
on the carbon emissions associated with
food, than whether it was grown in an
urban environment or not.
Using scarce urban
land for agriculture for
the purposes of climate
change mitigation was
not justifiable.
In reflecting on these findings, the research team concluded that with a limited
evidence base and the potential compromises required, using scarce urban land
for agriculture for the purposes of climate
change mitigation was not justifiable. As
the literature stands, it would be difficult
to reason why the resources, legislation,
land and trade-offs required for its implementation are necessary or cogent for this
purpose.
Transport
Why does it relate to food?
URBAN SYSTEMS AND
FOOD
As this research revealed, investing in urban agriculture as a
means to reduce the GHG emissions associated with feeding our
cities, may not be viable or beneficial. However, in carrying out
the research, the team at Arup found that many other systems of
a city interact with our food systems to result in significantly high
carbon emissions now being associated with feeding our cities.
These include our transport systems, land use decisions, water
and waste management, open space planning and development
policy.
Arup was interested in the way these systems interacted with
food systems, and how working with these systems may deliver
more meaningful results, compared to investing in urban agriculture, in terms of carbon emission reductions. These are preliminarily explored as follows.
The transport sector is responsible for an
estimated 23% of global CO2 emissions.
Planes, ships, trains, trucks and delivery
vans bring food into our cities. Individuals
then travel to stores to purchase these
foods. The way food is transported into
and around the city has a huge impact on
carbon emissions.
How could we respond?
While there is a growing awareness of the
issue of food miles, cities could look to
better understand the carbon emissions
associated with the way communities
access their food.
Are supermarkets serviced by public transport? Are there affordable food outlets
located within a walkable catchment of
residential communities? Is there appropriate walking and cycling infrastructure to
safely navigate large carparks of supermarkets? Are off-peak public transport services provided for weekend farmers markets?
Food and
Waste Water
Why does it relate to food?
Food which is imported into cities contains
large amounts of nitrogen and phosphorus. These valuable nutrients are usually
used as fertiliser to help increase yields
and ensure cities have enough food to eat.
When we prepare, eat and dispose of our
food, a large proportion of these nutrients
end up in our black and grey waste water
and garbage bins.
How could we respond?
In moving towards a low carbon future,
cities need to see these food scraps and
faecal material as resources rather than
waste. These waste streams contain valuable micronutrients which can be
captured and converted into a sustainable
form of energy or reused for fertiliser.
Are rubbish collection schemes provided for food waste? How can new water
treatment plants look to reuse these waste
streams? Are there surrounding farms that
could utilise the nitrogen and phosphorus
captured, instead of purchasing synthetic
fertilisers?
Eradicating the use of
synthetic fertilisers could
reduce agricultural GHG
emissions globally by 20%.
Land Use
Open Spaces
Why does it relate to food?
Why does it relate to food?
How could we respond?
Why does it relate to food?
How could we respond?
Many cities are surrounded by rich
agricultural soils which enable them to
meet their food needs locally, and keep
food miles and the associated carbon
emissions to a minimum. Growing urban
populations means this land is often being
converted for residential development, and
thus agriculture gets displaced to areas
much further away. Alongside this, forestry
land faces pressure to convert to agriculture so that food demands can be met.
Many urban residents have become disconnected from the food they eat; where
it is grown, how it is grown, and the impact
these - along with their dietary preferences
- may have on the environment.
Cities value and protect open spaces for
recreation, biodiversity,
community engagement and health –
could they also be used to help reconnect community members with the food
systems?
Urban planners continue to prioritise policies which deliver high
density development on the basis that it
will enable sustainable urban living. This
has unintended consequences on the carbon profile of our food systems. Apartment
living has meant people now have smaller
kitchens, no gardens, are unable to compost and have to travel further to purchase
fruit and vegetables. This has induced
demand for pre-packaged food, with its
associated food miles, high packaging, and
need for refrigeration.
Urban planners have the ability to place
conditions on certain types of development, when adverse consequences arise.
When these conversions occur, any carbon
which is stored in the soils and roots of
trees is released into the atmosphere and
the ability for any ongoing carbon absorption is immensely compromised.
Forests have the highest
rate of carbon sequestration of any type of land
use. As a result, land use
change currently accounts
for 11% of total greenhouse
gas
How could we respond?
City planners have an important role to
play in determining and regulating how
urban and rural land is used.
What consideration is given to the quality
of soil when making land use decisions?
What role could an agricultural green belt
play in delivering a low carbon future? How
can make better use of existing agricultural land? How can we use technology to
optimise alternative locations for agriculture such as marine, aquaponic or vertical
farming?
Cities can play an active role in making
plant-based foods more available and
accessible, and investing in sustainability
education to help assist a shift towards
these diets.
“A diet rich in plant-based
foods and with fewer animal source foods confers
both improved health and
environmental benefits”.
EAT-Lancet Commission
Development Policy
Are there existing open spaces which could
be repurposed as community gardens? Is
there an opportunity to host local farmers
markets in these spaces? How could the
areas be used to help improve awareness
and understanding of sustainable cooking
and eating?
Should apartments be required to provide
composting collection or create internal
courtyards which enable the growing
of leafy greens and herbs? Could office
buildings and transport centres be provide
opportunities for food delivery, minimising
private vehicle trips to the supermarket?
Should food outlets be required to inform
consumers of the carbon emissions associated with their operation?
WHERE TO NEXT?
Unlike other essential services such as
transport, water, and housing, our food
systems have largely and historically
been absent from the planning field. This
research began to recognise the role
urban planning could play in reducing the
carbon emissions associated with our food
systems. It found that urban agriculture
is unlikely to deliver the scale of change
required, and may result in too many tradeoffs to make it beneficial.
As such, Arup began to identify the need
to explore city systems more widely and
understand how these interacted with our
food systems in a way that may reduce the
carbon emissions associated with feeding
our cities.
Further research is needed to better
understand how these interactions can be
used to mitigate climate change, and the
feasibility and effectiveness of doing so.
•
How can we ensure people have the
ability to sustainably access food
through our transport planning?
•
How can we use soil quality to better
inform our land use planning?
•
How can we utilise our waste water
systems to reduce our dependence on
synthetic fertiliser?
•
How can we diversify existing open
spaces or abandoned infrastructure
to promote sustainable eating and
growing?
•
How can we use design guidelines and
development policy to better
facilitate composting and small-scale gardening on new apartment buildings?
It is proposed that a future Invest In Arup
project is developed, where a case study
on an existing city is carried out. This case
study should identify the carbon emissions associated with a cities existing food
system, and then develop and test ways
to minimise these through other urban
systems.
Understanding the way these other
systems interact with the food system to
mitigate or contribute to climate change
will enable us to better plan the transport,
housing development, urban design and
zoning of our cities so that they work together to achieve a low carbon future.