Livestock and greenhouse gas
emissions
Exploring the relationship
Tara Garnett
Food Climate Research Network
7 December 2007
About the FCRN – some
context
Funded by UK research council & based at
Surrey University
Focuses on:
• Researching food chain contribution to
GHG emissions and options for emissions
reduction
• Sharing and communicating information
on food & climate change with member
network
FCRN outputs
1. Four comprehensive studies so far:
1.
2.
3.
4.
Fruit & vegetables
Alcoholic drinks
Food refrigeration
Meat & dairy
2. Working seminars: To inform research
3. Mailings: regular news on food / GHGs to
670+ members
4. Networking: To catalyse further research
Presentation today
1.
2.
3.
4.
5.
6.
Trends production & consumption
Review of livestock-related studies
GHGs associated with system inputs
GHGs associated with system outputs
Mitigation options
Scenarios
7. Conclusions
Largely but not solely UK focused
Limitations
• Focus on GHGs and not other
environmental impacts
• Up to farm gate only (although leather,
wool and rendering upstream impacts)
• More on cattle than the other livestock
• No economic analysis – planned for future
study
Overall food-related contribution to
GHG emissions
• EU EIPRO report: 31% all EU
consumption related GHGs
• FCRN UK estimates: around 19%
(probably an underestimate)
• Defra estimates similar
Food consumption related contribution to UK
consumption GHGs (work in progress)
Fertiliser
manufacture
1.0%
Agriculture
7.4%
Food
manufacturing
2.2%
Packaging
(incomplete
data)
0.9% Transport incl
overseas
2.5%
Home food
related
2.1%
Non food
81.3%
Retail
0.9%
Catering
Waste disposal 1.5%
0.3%
1. CONSUMPTION TRENDS
UK consumption - meat
UK consumption – dairy ex milk
Milk consumption declining
Projected global trends in
demand
500
450
Million tonnes
400
350
Developing countries meat
300
Developing countries milk
250
Developed countries meat
200
Developed countries milk
150
100
50
0
1980
1990
2002
Year
Source: FAO 2006
2015
2030
1997
Global meat
demand by
animal type
2020
Source: IFPRI 2001
Policy influences
2. REVIEW OF LIVESTOCK
GHG CONTRIBUTION
Livestock GHG estimates
• Global – 18% (FAO)
• EIPRO – 15% (half all food impacts)
• Dutch study: half all food impacts
• UK (from this study):
– 6.6% production related GHG emissions
(NETCEN & other)
– 8% consumption emissions (Cranfield plus
volumes based on MLC & Defra)
But
• Livestock production yields food and non
food benefits – they ‘save’ having to
produce them by other means
• Make use of unproductive land &
byproducts
• We have to eat – there’ll always be an
impact
• Would non-animal substitutes be any
better for GHG emissions?
To understand why the impacts
arise and how/whether they can
be reduced you need to look at
• The inputs to livestock production and
GHG implications
• The outputs and GHG implications
3. THE INPUTS
The inputs
• Cereals: How much? Alternative
uses (food, biofuel)?
• Oilseeds: Second order impacts?
Relationship between cake and oil?
• Grazing land: Inputs to? Alternative
uses? Benefits of?
• Byproducts: Alternative uses?
• Land: What’s the best way of using
the land for most output at least
GHG cost?
• Energy: not discussed
• What are the
second order
impacts?
• What is the
opportunity
cost – could
these inputs
be used in
other ways?
Cereals
• UK: 50% wheat; 60% barley
• Globally: 33 – 37% cereals
• Cattle 50% feed cereals; pigs & poultry
50%
• Alternative uses?
– Direct human consumption (quality – wheat
grades? Nutritional comparability with meat?
– Biofuels?
Oilseeds - soy
• Soy – 40% oilseeds in livestock diet (av)
• By- or co-product?
– Soy volume: 20% oil 80% cake
– Soy value: 33% oil 67% cake
• Feed cake drives soy production – now
biofuels too
• Implications?
– Human diet
– Lost carbon sequestration – 2nd order impact
Human diet: oilseed
consumption
Soy – lost carbon sequestration
•
•
•
•
Brazilian soy 60% EU imports
Legal Amazonia – Cerrado & rainforest
Direct & indirect deforestation
Direct: doubling of soy cultivation in last
decade and could double again
• Indirect: push other industries onto land
• Plus of course Brazilian cattle ranching
• Lost C sequestration not captured in
standard LCA
Former forest, Matto Grosso
Brazil
Byproducts
• Livestock make use of byproducts –
resource utilisation
• How much production do byproducts
actually sustain?
• Could these byproducts be used for
something else? Opportunity cost?
• Quality of feed / methane?
• Are they byproducts produced near where
they’re needed?
Grassland
• 37% agric land used for grazing
• Grass not a free resource – fertiliser
inputs & significant N2O emissions
• Overgrazing globally - FAO estimates this
accounts for 7% global GHG emissions
• Some overgrazing in the UK and also
undergrazing
Grassland continued
• Carbon sequestration: appropriate grazing
makes sequestration pay BUT losses if
overgrazed)
• Alternative use: biomass cultivation? If:
– Price is right
– No disruption to soil (C losses)
• Or forest cover
Land: the big issues....
• Need to consider the opportunity cost of
using land for one purpose over another
– Land to feed animals or to feed humans?
– Land for feed production or for C
sequestration?
– Land for animal rearing or for biomass
production?
• Bearing in mind projected 9 billion by 2050
4. THE OUTPUTS
Livestock: The outputs
• Nutrition: protein, calcium, iron, B12, fat…
• Leather & wool
• Rendered products: glues, soaps, pet
food…
• Manure: nutrients and soil quality
• Soil carbon sequestration
• Landscape aesthetics & biodiversity
Questions
• What benefits do we gain from livestock
production?
• Are these benefits accurately accounted
for in life cycle analysis?
• How much do we need these products?
– (who defines need?)
• To what extent can we obtain these goods
/ services by non livestock means and
what would the GHG implications be?
Nutrition
Protein
• Global av 28.7 g protein a day* (ie. pure
protein not grams of meat or milk)
• Devpg world 21 g a day
• Developed world: 20% kcal from animal
products
• Developing world: 6%
Calcium, Iron & B12
• Dairy products good sources of calcium –
non meat alternatives available
• Red meat good sources of iron – non meat
sources available – anaemia global problem
• B12 – sources animals, yeast and (now)
fortification
General conclusions on meat,
dairy and nutrition
•
•
•
•
•
Good source of calcium, iron & Vit B12
Not so important for protein
Provides fat in excess
Livestock products not essential
But useful in small quantities esp. for
vulnerable groups
• Issues in developed world and extremely
poor in developing world different
Other benefits: leather and wool
• Leather : useful byproducts but not
‘needed’ at current levels (but devpg world
industries)
• Comes with own environmental downsides
• Wool: v. small textile player
Non-carcass & rendered products
• Are we making the best use of the carcass?
– Decline in offal consumption
– Trading of unwanted parts
– Pet food... (do we need to feed them all this?)
– Oleochemicals
– Energy
– Some waste
• Are there ways of consuming which would
enable lower livestock production levels?
• Post-BSE disposal problems – future risks?
Manure
• Costs & benefits
– Avoids need for mineral fertilisers (although
harder to optimise input levels)
– Contributes to soil quality / carbon
sequestering properties of soil
– Leads to methane and N2O emissions
• Manure isn’t necessarily where you want it
• Fertiliser needed in first place to support
animal feed production
Soil carbon sequestration
• Overgrazing and undergrazing
• Not relevant to all livestock types
Biodiversity & aesthetics
• Importance of grazing to biodiversity
• Overgrazing and decline in biodiversity
• 20% land degraded worldwide (73% in dry
areas)
• Overgrazing more of a problem than
undergrazing (though this may change)
• Grazing land in UK - biological interest?
• Aesthetics: We like what we know... Not a
question of all or nothing
5. MITIGATION
Relative importance of different
gases - GWP
Source: Williams AG (2007) per comm. Based on Williams, A.G., Audsley, E.
and Sandars, D.L. (2006) Determining the environmental burdens and
resource use in the production of agricultural and horticultural commodities.
Main Report. Defra Research Project IS0205.
Mitigation options
1. Husbandry
2. Changing management
3. Managing outputs
4. Changing numbers
• Need to consider all gases – pollution
swapping risk
• Framing issues: Animal welfare,
biodiversity, long term soil quality, rural
economy
• Trade offs inevitable: With other social /
environmental concerns & pollution
swapping
1. Husbandry for productivity
• Modifying diet:
– Concentrates
– High sugar grasses
– Legumes
– Nutritional supplements
• Animal breeding: for productivity /
longevity / multifunctionality
• Animal welfare & biodiversity?
• 2nd order C impacts of high cereal diet?
2. Changing management
• Soil inputs: reduce N inputs, soil
management, maximise N efficiency
• Intensive vs extensive: extensive more
nitrogen efficient?
• Organic vs non organic: Studies mixed –
long term soil fertility / C storage potential?
System vs individual differences?
• Housing: Manure management but animal
welfare?
3. Managing outputs
• Manure: AD
• Slurry and FYM heap management
4. Changing numbers
• Simplest ...and hardest
Key issues
• What do we decide to use our land and
other resources for?
• Need to bear projected 9 billion population
in mind
• And an 80% (more?) required cut in
emissions...
• Tackle problems in isolation or as a whole
- atomised vs synthetic approach?
6. SCENARIOS
The scenarios
•
•
•
•
•
•
•
Business as usual
Maximum productivity
Organic
Intensive plus extensive
Livestock switching
Marginal livestock rearing
NEED TO CONSIDER: other sustainability
& welfare objectives; second order
impacts; land opportunity cost
Maximum Productivity
GHG reduction
UK reduction but not elsewhere
Impact on human nutrition Nutritionally enhanced meat etc – otherwise little difference
Impact on non food goods Little impact – slight reduction
Rural economy
Little impact – gains for niche farmers producing
nutritionally enhanced products
Soil fertility
N surplus risk
Biodiversity
Most ruminant on biologically monotonous pasture. Scope
for some species diversity in upland areas
Aesthetics
Similar to today but less livestock in uplands
Animal welfare
Arguably negative
Land opportunity cost
Increased land for biofuels but conflict with land needed for
feed? Second order impacts lost carbon sequestration
potential on land overseas.
Organic
GHG reduction
Reduction on per area basis but not necessarily per yield
(although need to consider carbon storage)
Impact on human nutrition
If consumption reduced, possibly good
Impact on non food goods
Little impact – slight reduction
Rural economy
Depends on CAP etc- if consumers are willing to pay more
for organic he impacts could be beneficial
Soil fertility
Mixed results; greater use of manure and legume rotations
could have a positive effect
Biodiversity
Probably good
Aesthetics
Depends on the scale but probably positive
Animal welfare
Possibly good
Land opportunity cost
Less land available for other purposes. Lower reliance on
concentrates means land use impacts overseas lower
(although organic farming still depends on concentrates).
Intensive & extensive
GHG reduction
First order reductions, although second order impacts
unclear and probably negative
Impact on human nutrition
Unchanged from current situation; the total output of
livestock products may not change very greatly
Impact on non food goods
Rural economy
Soil fertility
Probably unchanged
This depends on CAP and other policy developments,
but the impacts could be negative if costs increase
relative to current methods.
Possibly positive
Biodiversity
No change if standard grass / grass-clover mixes are
sown although overgrazing may be reduced.
Aesthetics
Little change – some less intensive systems
Animal welfare
Extensive systems may benefit animal welfare although
management will be key
Land opportunity cost
High dependence on concentrates means potentially
negative impacts from lost carbon sequestration
overseas. Less land available for biofuels production
Livestock switching
GHG reduction
Impact on nutrition
Fewer CH4 emissions. Renewable energy could reduce C
intensity of p&p units. Second order impacts negative.
Problems could arise from pig and poultry manure surpluses
Chicken & (fatless) pork low in fat but less good for Ca & Fe.
Impacts on non food
Less leather & wool
Rural economy
Negative for ruminant farmers. Mixed for P&P – more
competition from more entrants could simply drive prices down.
Soil fertility
Biodiversity
Aesthetics
Animal welfare
Possibly negative - fewer livestock to fertilise grass land
Patchy - grazing land can be managed to maximise biodiversity
rather than grazing productivity but benefits of grazing lost
Negative in so far as we value seeing livestock grazing
Depends on the rearing system adopted
Land opportunity cost
More land needed to grow feed (but cattle eat cereals too).
Less available for food / biofuels. Lost sequestration potential.
Marginal livestock rearing
GHG reductions
More CH4/kg output; N use efficiency might decrease. Feed production
impacts & 2nd order impacts reduced. Overall GHG reduction through
number cuts and measures to reduce consumption
Impact on nutrition
Consumption would decline– positive but interventions needed to maintain
Ca & Fe levels among vulnerable groups. Cattle & sheep main meat .
Impact - non foods
Slight reduction in availability
Rural economy
Potentially v.damaging unless measures taken to raise the cost of livestock
products and increase returns to farmers. Potential for diversifying into other
areas eg biocrops
Possibly beneficial. Less manure available for arable land but area needed
for arable would decline (since feed cereals cut). Nutrient shortfalls could in
part be met from AD digestate and compost.
Depends on management; reductions in overgrazed areas will be good but
numbers will need to be maintained in undergrazed areas
Depends on management. If upland areas stocked appropriately then
favourable. Some changes may be seen as negative such as an overall
decline in the livestock we see on rural land.
Soil fertility
Biodiversity
Aesthetics
Animal welfare
Land opp cost
Poss beneficial although care is needed to maintain good nutritional health.
Positive - less lost carbon sequestration from overseas feed production.
Land could be used for arable or for biofuels.
7. THOUGHTS, QUESTIONS,
CONCLUSIONS
What I think is fairly certain
• Livestock impacts significant
• Some livestock production positively
beneficial
• But not at current levels...
• ...Or given current trends
• Techno-oriented mitigation approaches
don’t tackle second order impacts
• Nor relationship with other sustainability
objectives
And....
• Significant reduction in production and
consumption meat AND dairy needed
• We need to pay more for livestock
products
• We need to collaborate globally and think
strategically about how to make best use
of land
In other words
• In the context of 9 billion on planet by 2050
• What is the best use of global land so that:
– We are all fed adequately ...
– At minimum GHG cost?
– Stored carbon is not released?
– Biodiversity is protected?
– Other ethical non-negotiables upheld??
• Meeting Needs rather than demand - only
feasible approach
Thank you
Tara Garnett
taragarnett@blueyonder.co.uk
www.fcrn.org.uk
Food Climate Research Network