Life Cycles and Carbon Footprints | Wiedmann
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The Rights and Wrongs of Carbon Accounting About life cycles and footprints in the carbon world Carbon Accounting Conference Heriot-Watt University, Edinburgh - 11 March 2009
Transcript of Life Cycles and Carbon Footprints | Wiedmann
The Rights and Wrongs of Carbon
Accounting
About life cycles and footprints
in the carbon world
Carbon Accounting Conference
Heriot-Watt University, Edinburgh - 11 March 2009
The Challenge – “Counting
Emissions”
Methods
Case studies
Conclusions
Contents
Forum for the Future (2008) Getting to Zero: Defining Corporate Carbon Neutrality
GHG Protocol – Boundary Setting
Direct GHG emissions
Indirect GHG emissions (supply chain)
n4 n3
(…)
(…)
(…)
n5
(…)
n1
(…)
(…)(…)
(…)
(…)
n2
tC02·eq
Production layers
System completeness vs truncation
Product 1
Product 2
Carb
on f
ootp
rin
t (
t C
O2-
e)
Production layer
The Challenge – “Counting
Emissions”
Methods – Process LCA + IO-LCA
Case studies
Conclusions
Contents
Method 1: Process LCA
Table 1. Flows of products between unit processes
Production of Steel
Electricity
Production
Production of
Toaster
Use of Toaster
Disposal of toaster
Steel (kg) 1 - 0.5 - 2 0 0
Electricity (kWh) - 0.5 1 - 0.1 - 1 0
Toaster (unit) 0 0 1 - 1 0
Toast (piece) 0 0 0 1000 0
Waste disposal service (kg disp.)
0 0 0 -1 1
Table 2. Flows of environmental intervention by unit processes
Production of Steel
Electricity
Production
Production of
Toaster
Use of Toaster
Disposal of toaster
CO2 (to air, kg) 1 4 2 1 0.5
Process LCAProcess LCA
ModelModel
Process specificProcess specific
StrengthsStrengths WeaknessWeakness
Truncation, Truncation, laboriouslaborious
Method 1: Process LCA
Method 2: Environmental Input-Output Analysis
INDUSTRIES .
Agric. & raw mat.
Manuf. ind.
Electricity gen.
Transport sectors
Service sectors
PRODUCTS
5000 10000 15000 2000 100Food, minerals, fuels
3000 8000 8000 20000 2000Manufact. Goods
1000 6000 6000 10000 3000 Electricity
400 2000 2000 15000 5000 Distribution
50 1500 1000 5000 20000 Services
GHG emissions
200 300 250 150 100
Input-Output Input-Output LCALCA
ModelModel
Complete, less Complete, less resource intensiveresource intensive
StrengthsStrengths WeaknessWeakness
AggregationAggregationnot specificnot specific
Method 2: Input-output LCA
A hybrid of Process & EIO: Hybrid-LCA
Process LCAProcess LCA
Input-Output Input-Output LCALCA
ModelModel
Process specificProcess specific
EncompassingEncompassingsystem boundarysystem boundary
StrengthsStrengths WeaknessWeakness
TruncationTruncation
AggregationAggregation
HybridHybrid
LCALCA
HybridHybrid
LCALCA
Process specificProcess specific
EncompassingEncompassingsystem boundarysystem boundary
Process specificProcess specific
EncompassingEncompassingsystem boundarysystem boundary
Process specificProcess specific
EncompassingEncompassingsystem boundarysystem boundary
Process specificProcess specific
EncompassingEncompassingsystem boundarysystem boundary
Why a hybrid approach?
Further information
The Challenge – “Counting
Emissions”
Methods
Case studies
Conclusions
Contents
Total carbon footprint (CO2)
Food processing
Electricity
Cardboard and paper
Agricultural products
On-site (direct) emissions (13%)
Legal, consultancy and other business services
Wood and wood products
Misc service activities
Gas distribution
Office machinery and computers
Research and development
All other commodities
Wholesale distribution
Non-ferrous metalsMechanical machinery and equipmentPlastic products
Carbon Footprint of a food company
HIE – Internal & External Expenditure
Carbon footprint by production layer
Sector benchmarking
t CO2-e / £
Structural path analysis (SW H&C sector)
The Challenge – “Counting
Emissions”
Methods
Case studies
Conclusions
Contents
Save money and time – start with a top-down analysis to identify hot spots in your total carbon footprint
Follow-up hot spots on site and in your supply chain
On site: reduce energy use, emissions and costs
Supply chain: help (urge) others to reduce their carbon footprint
In-depth Hybrid LCA only if major insights & savings can be expected
Communicate your findings and experiences
Rights…
Don’t get lost in too detailed an analysis – keep the bigger picture in mind
Be aware of and manage uncertainty – don’t search for the last gram (of carbon)
Avoid presenting results (labels) without explanation
Do not leave out services – the impact of service activities is often underestimated
… and Wrongs of Carbon Accounting
THANK YOU
www.censa.org.uk
