Reconciling greenhouse gasemissions from measurements andmodelling in the land use sectorBob Rees, Kairsty ToppICARB works...
Reporting metrics• UK greenhouse gas emissions reported using  internationally agreed protocols (IPCC)• Provide simple rul...
IPCC approach to GHG inventory                                 IPCC 2006                                         3
Scottish GHG emissions                         NAEI 2012   4
Inter-annual variation of N2Oemissions                                                  5                                S...
Historic datasets                        70                        60                        50       Fr e q ue nc y      ...
Climatic controls of nitrous oxideemissions                                                      Scottish                 ...
Emissions calculations                                   Annual N2O emission (kg N ha-1)      IPCC default EF       assum...
Inventory comparison with Model Is the NAEI emission inventory overestimating UK N2O emissions?                           ...
DEFRA: improving N2O inventory                            UKIPCC Tier 1 N2Dynamics Model                                 S...
Process based modelling                     Soil Characteristics         Crop Parameters    Climatic Drivers              ...
Validation   Easter Bush   12   12
Daily nitrous oxide fluxes in the arable phase            of a rotation                   800g N2O-N ha-1 d-1             ...
Regional modelling• Homogeneous  Mapping Spatial Unit                              DNDC  (HMSU)                       etc....
Conclusions• Current inventory reporting of agricultural GHG  emissions provide a crude estimate of actual  emissions• Imp...
Upcoming SlideShare
Loading in …5
×

Reconciling greenhouse gas emissions from measurements and modelling in the land use sector | Bob Rees, Kairsty Topp

606 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
606
On SlideShare
0
From Embeds
0
Number of Embeds
124
Actions
Shares
0
Downloads
1
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Reconciling greenhouse gas emissions from measurements and modelling in the land use sector | Bob Rees, Kairsty Topp

  1. 1. Reconciling greenhouse gasemissions from measurements andmodelling in the land use sectorBob Rees, Kairsty ToppICARB workshop, 5 February 2013
  2. 2. Reporting metrics• UK greenhouse gas emissions reported using internationally agreed protocols (IPCC)• Provide simple rule based accounting system• Underpin C footprinting tools• Unlikely to reflect actual emissions• Unhelpful in guiding mitigation 2
  3. 3. IPCC approach to GHG inventory IPCC 2006 3
  4. 4. Scottish GHG emissions NAEI 2012 4
  5. 5. Inter-annual variation of N2Oemissions 5 Smith and Dobbie 2002
  6. 6. Historic datasets 70 60 50 Fr e q ue nc y 40 30 20 10 0 - 0 .0 1 0 .0 0 0 .0 1 0 .0 2 0 .0 3 0 .0 4 0 .0 5 0 .0 6 Emis s io n Fa c t o r ( %) An analysis of 237 individual historic UK observations. Buckingham et al 2012 6
  7. 7. Climatic controls of nitrous oxideemissions Scottish summersFlechard et al, Agriculture, Ecosystems and Environment 121 (2007) 135–152 7 7
  8. 8. Emissions calculations Annual N2O emission (kg N ha-1)  IPCC default EF assumes N2O emissions from soil are supply-related  But at least some 0 100 200 300 400 arable soil emissions Annual N2O emission (kg N ha-1) N application rate (kg ha-1) must be N-balance- related … because they will occur after the crop has taken up some fertiliser N 0 100 200 300 400 N application rate (kg ha-1) 8 Thorman et al, 2012
  9. 9. Inventory comparison with Model Is the NAEI emission inventory overestimating UK N2O emissions? 250 200 150 kt N2O/y 100 50 0 1990 1995 2000 2005 2010 NAME 5th 95th Inventory A. Manning 9
  10. 10. DEFRA: improving N2O inventory UKIPCC Tier 1 N2Dynamics Model Specific Tier 3 N Dynamics Model Inventory 1% fn{N 10% type, Soil temp} NDevelopment 2 O EFDeposited NH3 fVolatilisation programme will Emissions Deposition N Type Soil Temperature improve structure and 2.5% fn{Soil 28% 30% type}Internationa fLeached l Reporting refine EFLeachate Emissions Model N Leached Emissions Soil Type N Type Factors via plot fn{N type, 0.8% 1.25% SMC, pH} National N/Manure to field scale EFDirect Reporting Applied measurementsSoil Moisture Content Soil pH GHG platform programme 10
  11. 11. Process based modelling Soil Characteristics Crop Parameters Climatic Drivers Farming Practices Crop Growth/ Climate Soil Development Physics Soil C,N Biochemistry Crop Production Trace Gas Emissions Soil C, N Dynamics N leaching 11 DNDC
  12. 12. Validation Easter Bush 12 12
  13. 13. Daily nitrous oxide fluxes in the arable phase of a rotation 800g N2O-N ha-1 d-1 Fertiliser 600 applications 400 200 0 01-Jan 01-Mar 30-Apr 29-Jun 28-Aug 27-Oct 26-Dec DNDC 9.2 Rees et al, 2008 13
  14. 14. Regional modelling• Homogeneous Mapping Spatial Unit DNDC (HMSU) etc. – Soil type – Slope – Land cover – Admin boundaries – agronomic practices and climate are similar 14
  15. 15. Conclusions• Current inventory reporting of agricultural GHG emissions provide a crude estimate of actual emissions• Improved reporting will help improve the accuracy of emissions and help to deliver mitigation• Revised emission factors in improved modelling will provide opportunities for the development of farming systems with reduced environmental impact 15 15

×