Agriculture and Climate Change: Impacts and Solu7ons...FAO Reports • Livestock’s Long Shadow...
Transcript of Agriculture and Climate Change: Impacts and Solu7ons...FAO Reports • Livestock’s Long Shadow...
AgricultureandClimateChange:ImpactsandSolu7ons
Richard Young Sustainable Food Trust
Castle Debates
Sainsbury’s Store Support Centre
10 June 2016
FAOReports• Livestock’sLongShadow2006es7mated18%ofGHGdue
tolivestock• Tacklingclimatechangethoughlivestock2013es7mated
14.5%ofGHGemissionsduetolivestock(41%frombeef,20%frommilk)
• However,thesefiguresincludelandusechange,butonlyforSouthAmericaandtheCaribbean(seepage106)
• Theymakenoallowanceforlandputintowoodlandorbacktograss,asintheUK,andalsoexcludeongoingsoilcarbonandmethanesinklossfromcropland.
• ThereportalsofailstoconsidertherealreasonswhycaUleencroachedonrainforestlandinSouthAmerica.
•
-20
-15
-10
-5
0
5
10
15
20
25
30Livestockemissions Cropland Se4lements Wetlands Otherlanduses Grassland ForestLand
MillionTo
nnesCO₂e
quivalen
t
UKLivestockMethanec/wLandUseEmissions
Entericfermenta7oncaUle Entericfermenta7onsheep
Manuremanagement Othermethaneemissions
Usingdatafrom:Milesetal.(2014)’EmissionsandRemovalsofGreenhouseGasesfromLandUse,LandUseChangeandForestry(LULUCF)forEngland,Scotland,WalesandNorthernIreland:1990-2012’CentreforEcologyandHydrology,DepartmentofEnergyandClimateChangeContractGA0510Defra(2015)AgriculturalSta7s7csandClimateChange,6thEdi7on
Intensivechickenproduc7onisamoreefficientwaytoproduceproteinthanbeefproduc7on.Butpoultryneedhighqualitygrainandprotein,bothofwhichcomeatahighenvironmentalcostandindoorproduc7onsystemsaremajorsourcesofammoniaandnitrousoxide..CaUle,ontheotherhand,cangrazegrass,whichwecannoteatandarebeUerabletou7lizearablebi-productsthanchickens.
WherecaUlearerearedexclusivelyongrassandclover,thereisalsononeedfornitrogenfer7liser,amajorsourceofgreenhousegasemissions.Andifweacceptedthatbeeffatfromgrass-fedanimalsisashealthyaspalmoilandhealthierthansoyabeanoil,theefficiencyofbeefproduc7onwouldbeseentoalmostdouble.
CopyrightNaimAlelhUps://en.wikipedia.org/wiki/File:Птичник.JPG
Likelambstotheslaughter
0
1
2
3
4
5
6
7
2000 2005 2010 2011 2012 2013 2014
Per
Cap
ita C
onsu
mpt
ion
(kg)
Year
UKsheepmeatconsump7on2000-2014 UKlambconsump7onbyagegroup
32%fallsince2000(40%fallsince1995)
Source:AHDBBeef&Lamb
Thesoildegrada7onproblem
SoilCarbon
FAO2009.FoodSecurityandAgriculturalMi7ga7oninDevelopingCountries:Op7onsforCapturingSynergies
• Landusechangefromna7veforestsandnaturalgrasslandstoagriculture,
especiallycon7nuousarablecropproduc7oncontributestoGHGemissions
throughthemineralisa7onofsoilcarbonanddecomposi7onofvegeta7on.
• Landusechangeises7matedtohavecontributed55-135billiontonsofcarbon
emissionasCO2duringtheperiod1850-1998.
• Conversionofcroplandtograsslandleadstoanaverage19%increaseinSOC
• Recentresearchhasshownthatoncesoilcarbonfallstoolow,maximumcrop
yieldscannotbeachievednomaUerhowmuchfer7liserisused
Importanceofgrazinglivestock• Grassistheonlymajorfoodcropapartfromtreesthatcanrebuildsoilcarbonand
reversesoildegrada7on.Butwecan’teatit,howeverhungryweare.
• Grazinganimalsneededtomakecommercialuseofgrassandforagelegumes
• Foragelegumesprovidetheonlysignificantwaytointroducesufficientnitrogen
intosoilstosustainhighproduc7vity,otherthanusingnitrogenfer7liser
• EUconsumerspay€35-230billionannuallyforthehiddencostsofNfer7lsier
• Clovercanfixupto180kgN/ha/yr;Lucerne(alfalfa)over200kgN/ha/yr
• TheUKpredominantlypastoral,butwealsoneedforgrassincroprota7ons
• Weneedtodis;nguishbetweengrass-andgrain-fedruminants
9
SOCchangesfollowinglandusechange,Rothamsted
40
30
20
10
01960
90
1940
70
50
80
100
60
20001980
Year
Org
anic
C in
soi
l, t h
a -1
Startedarable
Startedgrass
Johnstonetal(2009)AdvancesinAgronomy101,1-57
Trial1☐Grasskeptasgrasso Grassconvertedtoarable� Arablekeptasarablen Arableconvertedtograss
UNEPreportin2013restatesclaimthatno-7llagricultureincreasesSOC,andes7matethatagriculturalemissionscouldbereducedbyup4.3bntonnesCO2p.a.with89%ofthisfromno-7llagriculture.Powlsonetal.2014find,frommeta-analysisofpublishedstudies,thatapparentincreasesofSOCintoplayersofsoilareinvariablyoffsetbylossesatdeeperlevels.
9%
Butwhataboutmethane?• Methaneconcentra7on2.57meshigherthanpre-industriallevels• Shorthalflifeofmethanemakesitimportantreavoidingrunawayclimate
change
Nazariesetal.2013.Methane,microbesandmodelsEnvironmentalMicrobiology15:2395-2417
Isruminantmethanesuchabigissueaswe’vebeenledtobelieve?
• Methanelevels2.57mepre-industriallevelsandresponsibleforc.16%ofglobalwarming
• Ruminantsresponsibleforc.17%ofallsourcemethaneemissions(27ofanthropogenicmethane).
• Soruminantmethaneresponsibleforc.2.7%ofglobalwarmingor4.3%ofhuman-inducedwarming.
• Notinsignificantbutallthecarboninthemethaneisrecycled.WhenruminantmethanebreaksdowntoCO2andH2Oisdoesnotaddtoatmosphericcarbonoroceanacidifica7on,unlikefossilfuelmethane.
Soyaandourneedforfat• EUimports30MTp.a.from20millionhectares• Soyabeansbreakdownto79%proteinmeal,mostlyforlivestockand11%oil
• But80%oftheoilusedinprocessedfoodforhumans,19%biodiesel,1%cosme7csetc.
• 35%ofourenergyintakecomesfromfatsandoils,sowoulds7llneedalltheoileveniftherewerenolivestocktoeattheprotein
• Increasingdemandforpalmoil• Oilseedrapemaincauseofpollinatorloss.
16
RichardYoungPolicyDirector
SustainableFoodTrustrichard@sustainablefoodtrust.orgwww.sustainablefoodtrust.org