Food for thought: Nitrogen too much of a vital resource? · Outline of my presentation •Why...
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N Food for thought: Nitrogen too much of a vital resource? Jan Willem Erisman
Transcript of Food for thought: Nitrogen too much of a vital resource? · Outline of my presentation •Why...
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Food for thought: Nitrogen too much of a vital resource?
Jan Willem Erisman
LouisBolkInstitute:for sustainableagriculture,nutrition and health
Outline of my presentation
• Why Nitrogen• Sources of reactive nitrogen• Efficiency of Nitrogen use• Effects of Nitrogen• Nitrogen and Diets• Your personal Nitrogen Footprint• What can be done to solve the N issue?
§ Nitrogen is necessary for life
§ 78% of N on Earth is N2 and unusable by organisms
§ To sustain human life, we convert N2 to reactive forms
§ The Green Revolution is largely due to synthetic N fertilizers
§ N2 is converted into Nr for production of fertilizer, food, feed, fibre, fuel, plastics, explosives, etc.
§ Humans depend on internal combustion for transportation and energy
§ Yet, Planetary boundaries for N have been exceeded: N has direct and indirect impacts on the climate system, biodiversity loss, air and water quality, stratospheric ozone destruction, etc.
Whycareaboutnitrogen?
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Anthropogenicandnaturalprocessescreatereactivenitrogen
• OnlyalimitedamountofNr iscreatedinnature:99.97%residesintheatmosphereinarelativelyinertform
• Ecosystems(biodiversity)arebasedonlowavailability
Erisman et al. (2015)
Globaltrendsinhumanpopulation,Nr,CO2andgrainandmeatproduction
48%oftheglobalpopulationeatbecauseoffertilizersErismanetal.2008
Uneven distribution• More than 2 billion people in the world suffer from
(micro) nutrient deficiency, especially in developing countries. Most critical are protein-nitrogen, phosphorus, calcium, zinc, iron, iodine
• An increasing number of people is obese• Probably 20% of the population ‘eats’ 80% of the
fertilizer
United States, The Revis family$341.98/week
Chad The Aboubakar family$1.23
Photo’s: Peter Menzel, Faith D'Aluisio
Increase inoverweight and obesity withkcalconsumption and fertilizer application
Erisman et al. (2017)
Nitrogenstimulatesallgrowth
David,MichelangeloBuonarroti (1475- 1564)
ENVIRONMENT
Food Production: NUE = 10 – 50%
N
Energy Production: NUE = 0%
N
Nitrogenuseefficiency
ChangesinanimalproductionsystemsincreasingNleakage
From a system once closely linked to local feed inputs and nutrient cycles
to one in which the production process are separated from feed production and manure application
Faculty of Earth and Life Sciences
2011 NH3 distributionVan Damme et al. 2014
Ammonia satellite observations
ThefivekeythreatsofexcessN
DisturbanceoftheglobalNcycleisfargreaterinmagnitudethanourmodificationoftheCcycle
ENA, 2011
VisibleimpactsofterrestrialNpollution:biodiversitylosses
N-poor natural ecosystems
LossofbiodiverseunderstoreyLossofsensitivelichenspeciesBiodiversitylossinfarmedmeadows
BiodiversewoodlandunderstoreyLichenssensitivetoairpollutionWildflowerbiodiversityinmeadowsN-enriched ecosystems
Visibleimpactsofcoastalnutrientpollution:implicationsforcoastalcommunities
Caulerpa,FloridaGreentides,BrittanyFishkills,GulfofMexicoShell-fisheryclosure
UnderthemicroscopeMicrocystis bloom,BalticNoctiluca tides,NewZld.Phaeocystis foam,NL
Jones, 2015
Data fromLe Quéré (2010)
Global carbon cycle, 2000-2008
+ denotes flux to atmosphere- denotes flux from atmosphere1 Pg = 1015 g = 1 Gt (Giga ton)
Fossil fuel combustion +7.7 Pg C yr-1
Land use +1.4 Pg C yr-1
Ocean uptake -2.3 Pg C yr-1
(25%)
Land uptake -3.0 Pg C yr-1
(33%)
Atmospheric growth +4.1 Pg C yr-1
(45%)
Residual +0.3 Pg C yr-1
(3%)
Nitrogenandthecarboncycle
N deposition increased carbon storage by:~0.3 Pg C yr-1 in terrestrial systems~0.3 Pg C yr-1 in marine areas (Blue Carbon)Limitations of P, other nutrients ..?
Galloway et al. 2003
Toomuchnitrogen:inacascade
TheunintendedcostsofNitrogentosociety
40% agriculture70% air pollution60% human health≈0% global warming
ENA, 2011
• WillingnessToPay:topreventNdamage70-320bln €(EU,2000)
• Addedvaluefortheprimarysector(agriculture)similartoexternalcost
• Globalextrapolation:200– 2000bln US$
Chicken Breast
Grocery store cost: 3 EuroHealth/environment cost: 1.1 EuroTotal cost = 4.1 Euro
Steak
Grocery store cost: 7 EuroHealth/environment cost: 1.9 EuroTotal cost = 8.9 Euro
EconomicNfootprintoffoods:www.n-print.org
Broccoli
Grocery store cost: 1.5 EuroHealth/environment cost: 0.2 EuroTotal cost = 1.7 Euro
Milk
Grocery store cost: 1 EuroHealth/environment cost: 0.4 EuroTotal cost = 1.4 Euro
Challenge:
Optimizing the use of nitrogen, while minimizing the negative impacts
Benefits:
• Necessary for life• Nitrogen fertilizer
supports food supply
Drawbacks:
• Excess reactive nitrogen negatively affects environmental and human health
The Nitrogen Dilemma
Personal N footprint
Anitrogenfootprintistheamountofreactivenitrogenreleasedtotheenvironmentasaresultofanentity’sresourceconsumption
Whatisanitrogenfootprint?
Whatmajorsectorsarecommonlyincludedinanitrogenfootprint?
Food*
*Foodconsumptionandproduction
Utilities Transport
FoodNfootprint:Definitions
Foodconsumption=Nthatentershumanmouth
VirtualN=FoodproductionN=Nlosttotheenvironmentduringthefoodproductionprocess
Farm
NInputs
ConsumedN
Leaching,runoff,volatilization,denitrification
Supplychain
Consumers
Foodwaste
Foodwaste
VirtualNFactor =∑NLossesConsumedN
NLosses:
Nefficiencyoverthefoodchain
3 oz steak15 g protein
TheimpactofFOODCHOICESonaNfootprint
ENVIRONMENT
ENVIRONMENT
½ cup beans15 g
protein
Calculate your nitrogen footprint at:
www.N-Print.org
Personal N footprints
0
2
4
6
8
10
12
14N
foot
prin
t (kg
N/c
apita
/yea
r)
PersonalNfootprintintheUS
Energy useFood consumption
0
2
4
6
8
10
12
14N
foot
prin
t (kg
N/c
apita
/yea
r)
PersonalNfootprintintheUS
Energy useFood productionFood consumption
Total: 39 kg N/yrFood: 28 kg N/yr
Consumption: 5 kg N/yrProduction: 23 kg N/yr
Energy: 11 kg N/yr
Whattheworldeats:PersonalNfootprintsaroundtheworld
USA Japan Germany Chad
05
10152025303540
N fo
otpr
int (
kg N
/cap
ita/y
ear)
*Preliminary
Goods & Services
Transport
Housing
Food production
Food consumption
PersonalNfootprintbycountry
05
10152025303540
N fo
otpr
int (
kg N
/cap
ita/y
ear)
Goods & Services
Transport
Housing
Food production
Food consumption
Food makes up more than 75% of a personal nitrogen footprint
*Preliminary
PersonalNfootprintbycountry
CalculateyourNfootprint:www.N-PRINT.org
OptionsforreducingYOURfootprint
Energy:• Reduceutility
usage• Publictransit• Reduce,
reuse,recycle!
Food:• Recommendedamountof
protein• Lessanimalprotein• LessN-intensivemeat• Foodfromsustainable
farms• Reducefoodwaste
0
5
10
15
20
25
30
Nfo
otprint(kgN/cap
/yr)
Current N consumption: 5.3 kg N/cap/yrRecommended N consumption: 3.0 kg N/cap/yr
Food production
Food consumption
Scenarios: US personal N footprint
0
5
10
15
20
25
30
Nfo
otprint(kgN/cap
/yr)
Food production
Food consumption
-11% -14% -14% -16%
Current N consumption: 5.3 kg N/cap/yrRecommended N consumption: 3.0 kg N/cap/yr
Scenarios: US personal N footprint
0
5
10
15
20
25
30
Nfo
otprint(kgN/cap
/yr) -11% -14% -14%
-43%
-16%
Current N consumption: 5.3 kg N/cap/yrRecommended N consumption: 3.0 kg N/cap/yr
Food production
Food consumption
Scenarios: US personal N footprint
0
5
10
15
20
25
30
Nfo
otprint(kgN/cap
/yr)
-66%
-11% -14% -14%
-43%
-16%
Current N consumption: 5.3 kg N/cap/yrRecommended N consumption: 3.0 kg N/cap/yr
Food production
Food consumption
Scenarios: US personal N footprint
FacultyofEarthandLifeSciences(2006 cover of The Economist)
PastandfutureNdeposition
Lamarque et al. 2013
Inordertomeettheplanetaryboundariessystemchangesareneeded
Rockström et al. 2009 Nature
Aresilientfoodsystemrequiresasystemapproach
ProductNfootprint(gN/kgfood)fordifferentfooditemsinAustriaxx Pierer et al
2014
