Challenges and opportunities for nitrogen emission reduction strategies

Mark Sutton and Oene Oenema

(co-chairs TFRN)

Air Science Policy Forum 15 April 2013, Dublin

www.clrtap-tfrn.org

Nitrogen oxides

(NOx)

Nitrous Oxide

(N2O)

Ammonia

(NH3)

Leached Nitrate

(NO3-)

Further emission

of NOx & N2O

carrying on

the cascade

Natural ecosystems

Ammonium nitrate

in rain (NH4NO3)

Nitrate in streams,

groundwater &

coastal seas

High temperature

combustion

& industry

Nr

Livestock farming

for food Nr in

manure

Eventual

denitrification

to N2

Simplified view of the Nitrogen Cascade

Unintended

N flows

N form in

the cascade

Terrestrial

Eutrophication

Freshwater Eutrophication

Greenhouse

gas balance

Particulate

Matter

Tropospheric

ozone

formation

Stratospheric

ozone loss

Soil acidification

Urban air

quality

Marine Eutrophication

Environmental

concern from Nr

Sutton et al. (2011 ENA)

Fertilizer

manufacture

Crops for food &

animal feed

Crop biological

nitrogen fixation

Intended

N flow

Challenges & Opportunities

Challenges

• Nitrogen flows are interlinked: Need to avoid pollution

swapping

• Much of the problem is related to agriculture, especially

livestock (80% harvested N to animals)

Opportunities

• Nitrogen flows are interlinked: Opportunity for synergy in

reducing multiple impacts

• Opportunity to improve Nitrogen Use Efficiency

• Many mitigation opportunities in agriculture still available!

Nitrogen biodiversity and carbon sequestration

Moninea Bog, Natura 2000 Site, Northern Ireland

Bog moss

Sphagnum imbricatum

Threats to ecosystem services

and recovery prospects • Timescales of recovery vary substantially

• Fast recovery possible (order 10 years)

– Epiphytic biodiversity

– Heathland (with active restoration)

• Slow recovery (several decades)

– Forest ground flora (dynamic models…)

– Peatland carbon sequestration…

Summary of N flows in Europe

Humannutrit.

agricult

soils

Livestock

farming

Atmospheric N2 pool

Crop

production

Atm

depos

17.6

7.1

11.8

1.5

2.14.5

2.3

1.0

3.1

Net import of

food & feed

2Crop

N2fix

Fertilizers

11.23.8

NH3,NOx

& N2O

emission

Denitrifi-

cation

N2 fixindust

& traffic3.4

Europe (EU27), around 2000. N fluxes in TgN/yr

Export by

rivers to

the sea

Net atmosph. export

9.3

2.4

3.5

6.84

6

13.8

0.4

4.75.8

3.7

0.8

3.2

0.1

Semi-nat.

soils

Nat N2fix

Wood exp.

Atmospheric NH3, NOx, N2O

wwt

Leaching

& runoff

0.3

2.41.4

0.2

3.8

0.2

0.2

4.7

6

4

3

2

1

5

7

ENA, 2011

Agriculture 1. Improving nitrogen use efficiency in crop production

2. Improving nitrogen use efficiency in animal production

3. Increasing the fertilizer N equivalence value of animal manure

Transport and Industry 4. Low-emission combustion and energy-efficient systems

Waste water treatment 5. Recycling nitrogen (and phosphorus) from waste water systems

Societal consumption patterns 6. Energy and transport saving

7. Lowering the human consumption of animal protein

Seven key actions for better

nitrogen management

ENA, 2011 and Nature 14 April 2011

The Way Forward:

More efficient N use saves farmers money

reducing nitrogen air pollution,

while being needed to meet Parties’

commitments for climate and water pollution

Short-term needs

- Updating of the Ammonia Guidance Document

- Options for the revision of Annex IX on Ammonia

Long-term needs

- Development of integrated perspective on nitrogen

- European Nitrogen Assessment

- New Guidance Document on Nitrogen Budgets

- Nitrogen and the Green Economy

Task Force on Reactive Nitrogen

contributions to UNECE CLRTAP

Targets Emissions reduction targets (% decrease from reference)

Thresholds Farm size (EU: 72% cattle on 13% farms),

Tanker size for manure spreading (IE: 60% with >10 m3)

Annex IX measures: ambition levels and thresholds

Overview of costs of ammonia

abatement measures

Measures Cost, €/kg NH3-N saved

Nitrogen management -1.0 to 1.0

Feeding strategies -0.5 to 1.0

Animal housing 0.0 to 10.0

Covering slurry storages 0.1 to 4.0

Slurry application -0.5 to 3.0

Urea application -0.1 to 4.0

5 top priorities

for ammonia mitigation 1. Low-emission land application of manure & fertilizer:

a) Application of cattle, pig & poultry slurry & solid manure

b) Low emission use of urea fertilizer (ban is not proposed)

2. Animal feeding strategies to reduce N excretion, from

cattle, pig & poultry.

3. Low-emission techniques for all new manure stores for

cattle and pig slurries and poultry manure.

4. Strategies to improve N use efficiencies and reduce N

surpluses, with N balances on demonstration farms,

5. Low-emission techniques in new and largely rebuilt pig

& poultry housing.

Slurry spreading: a wide range of low-emission

techniques are available

The car and the exhaust pipe…

Splash Plate Spreader

- 1950s technology

Trailing Shoe Slot Injector

Trailing Hose

EU benefit-cost ratios for

NH3 and NOx mitigation

Van Grinsven et al. (2013, ES&T in press)

NH3 NOx

Concluding remarks

Low-cost nitrogen mitigation must increasingly

focus on ammonia.

The options have been described in detail in

the draft Annex IX and the UNECE Guidance

Document.

Ammonia abatement is part of improving

Nitrogen Use Efficiency, helping meet climate

& water pollution targets, with significant

economic benefits.