1. Updated LCA Climate Metrics
Presentation at meeting of US TAG 207
August 4, 2014
Washington, D.C.
Tobias C. L. Schultz and Stanley Rhodes
SCS Global Services

2. Public Discussion and Review of LCA Climate Metrics
LCA Climate Metrics are included in a publicly available draft ANSI standard, which has completed its public comment period.
The metrics have separately been reviewed by industry, government, ENGOs, and leading climate scientists, with widespread support.
Applications of the metrics have been presented to:
American Geophysical Union (December 2013).
UNEP-SETAC (Basel, 2014).
American Center for LCA (October 2013).
And others.
Metrics will be presented to presented to SETAC North America in November.

3. The Global Climate Cause-Effect Chain based on IPCC AR 5
Scope of LCA Characterization
1. Emissions released, human-caused and natural
2. Increasing atmospheric
concentrations
3. Increases in global and regional radiative forcing
4. Additional heat trapped in the Earth-atmosphere system from integrated radiative forcing
5. Increase in the Global Mean Temperature (GMT)
6. Accelerating climate change as GMT rises above key thresholds
To model environmental mechanisms, you start with stressors, then follow the cause-and-effect sequence through midpoints to their ultimate effects, or impacts.
Here is the stressor-effects model for the global climate change environmental mechanism. It starts with the stressors – in this case the emissions released…
Now let’s take a few minutes to talk about these radiative forcing midpoints.
7. Dangerous impacts to resources, ecosystems, frequency and intensity of extreme events, coastal areas.

4. Environmental Relevance According to ISO 14044
ISO § : “Environmental relevance encompasses a qualitative assessment of the degree of linkage between category indicator results and category endpoints: for example, high, moderate or low linkage.”
ISO recommends that indicators used in comparisons should be environmentally relevant, and that environmental relevance should consider:
⎯ the condition of the category endpoint(s),
⎯ the relative magnitude of the assessed change in the category endpoints,
⎯ the spatial aspects, such as area and scale,
⎯ the temporal aspects, such as duration, residence time, persistence, timing, etc.,
⎯ the reversibility of the environmental mechanism, and
⎯ the uncertainty of the linkages between the category indicators and the category endpoints.

5. Selecting Environmentally Relevant Indicators
Node in cause effects chain
As one proceeds along the cause- effects chain, the relevance increases, but the uncertainty in measurement also increases.
Environmental relevance is the degree of linkage to endpoints, considering both these sources of uncertainty.
The most environmentally relevant indicator is selected subject to these constraints.
Environmental relevance

6. Environmental relevance
Selecting the Environmentally Relevant Indicator for Global Climate Change
Integrated radiative forcing
Environmental relevance

7. Radiative Forcing The Earth is continually bathed in
radiative energy from the sun.
Upon entering the Earth’s atmosphere:
Some sunlight is reflected (scattered)
Some is absorbed in the atmosphere
Some is absorbed by the Earth’s surface
Some is reflected by the Earth’s surface
The Earth’s surface emits infra-red radiation:
Some escapes into space
Some is absorbed by the Earth’s atmos- phere on its way out (the greenhouse effect)
I realize that most of you understand radiative forcing, but as it is essential to the climate accounting metrics, I just wanted to take a moment to review it quickly.
Image source:

8. Radiative Forcing Anomaly
Climate forcers warm or cool the Earth, by absorbing or reflecting radiative heat.
Anthropogenic emissions have increased concentrations of many climate forcers. These forcers can:
Increase the amount of radiative heat trapped (warming)
Increase the amount of sunlight reflected (cooling)
Radiative forcing is a measure of the net additional heat trapped by a climate forcer.
It is measured in Watts per meter squared (W/m2), or milli-Watts per meter squared (mW/m2). It can be positive or negative.
Image source:

9. Understanding the Effects from Changes in Radiative Forcing
The Krakatoa volcanic eruption dropped Global Mean RF by -3.4 W/m2, causing global temperatures to drop by ~1°C for three years, resulting in widespread crop losses and famine.

10. Black Carbon: The Second Most Powerful Climate Forcer (Global Mean RF =+1.1 W/m2)
Black Carbon Hot Spot over South Asia
Δ RF =+12 W/m2
Size = 1 million sq. km.
Duration: Constant year-round
Sources: Cooking fires, coal combustion
Radiative Forcing of Black and Brown Carbon (W/m2)
Source: Chung, C.E., V. Ramanathan, et al

11. Using Radiative Forcing to Develop Climate Metrics
GWPs are a measure of global mean integrated radiative forcing, over a time horizon.
This is compared to the integrated forcing of CO2 over the same time horizon.
GWPs have been established for all types of climate forcers.
The updated metrics the GWP measurement, but the factor is called the Global Forcing Potential (GFP).
The IPCC AR5 notes that “Global Warming Potential” can be a misleading term:
GWP does not consider temperature, only forcing, and do not consider coolants.
20 Years
100 Years

12. Key Parameters in Assessing Integrated Radiative Forcing
Accounting for all climate forcers (both positive and negative climate forcers).
Selecting the time horizons based on maximum temperature targets.
Including indirect effects on the climate (e.g. for methane and black carbon).
Developing characterization factors to account for regional and source variability.
Using updated terminology.

13. Key Features of the Updated Climate Metrics

14. LCA Metrics Include All Major Climate Forcers (Total Global Net Forcing =+2.3 W/m2)
Kyoto Climate Forcers list
(41%)
Radiative Forcing (2011)
Carbon dioxide
1.8 W/m2
Methane
0.5 W/m2
Nitrous oxide
0.2 W/m2
Other WMGHGs (CFCs, HCFCs, etc.)
0.3 W/m2
Total
2.8 W/m2
Short-Lived
Climate Forcers (27%)
Radiative Forcing (2011)
Black carbon
1.1 W/m2
Brown carbon
0.3 W/m2
Tropospheric Ozone
0.4 W/m2
Total
1.8 W/m2
Cooling Climate Forcers
(32%)
Radiative Forcing (2011)
Cooling aerosols
(sulfate, nitrate, and organics)
-2.1 W/m2
Source of cooling: Ramanathan, V., and Y. Xu 2010. The Copenhagen Accord for limiting global warming:
Criteria, constraints, and available avenues.  PNAS, vol. 107, no. 18, ; May 2010.
Source of black carbon forcing: Bond 2013, et al., Bounding the role of black carbon.
Source of data on brownc arbon:
Feng, Y., V. Ramanathan, and V. R. Kotamarthi. Brown carbon: a significant atmospheric absorber of solar radiation? Atmos. Chem. Phys., 13, , 2013.

15. Targets are linked to Temperature Thresholds
+4°C
+2°C
+1.5°C
You can verbally reiterate Mike’s point.
As Mike described earlier, the calculation of global warming potentials, or GWPs, based on the the standard IPCC equation involves the selection of incorporate a time horizon
Thresholds of increasing irreversibility

16. Significance of these Temperature Thresholds
Projected impacts when GMT anomaly reaches +2.0°C.
Projected impacts when GMT anomaly reaches +4.0°C.
Even with global mitigation of all emissions, the +1.5°C GMT anomaly will be exceeded.
Unprecedented heat extremes: July in the central U.S. will be 9°C (20°F) warmer
3 feet of sea level rise
+1.5°C Threshold (2035) Possible point of Arctic destabilization, and projected loss of small island states into the oceans. +2.0°C Threshold (2050) The point beyond which dangerous climate interference will occur, according to international consensus. +4.0°C Threshold (2100) This threshold is considered by many scientists to be “potentially catastrophic“.
2000
2050
1950
1900
The Alliance of Small Island States and 49 Least Developed Countries have advocated that the +1.5°C be selected as the maximum temperature target under UNFCCC agreements.
1.5°C
In the 2009 Copenhagen Accord, +2.0°C was agreed to as the maximum temperature target. The United States was a party to this agreement.
Effects to water supplies , including a 40% reduction in surface water supplies in the Mississippi River Basin.
As much as an 80% reduction in surface water in the Mississippi River Basin.
Significant declines in food production in all world regions.
Coral reefs decimated by bleaching.

17. Potential Consequences of the +4.0°Temperature Threshold
+4.0°C: last exceeded 25 millions years ago

18. Complete Accounting Reveals New Mitigation Opportunities
2000
2050
1950
1900
“Dangerous” warming per Copenhagen Accord
Current metrics hide potential of projects for reducing black carbon emissions. They underestimate the benefit of projects to reduce methane emissions. As discussed, these types are projects are necessary to avoid exceeding +2°C.

19. Including Short Lived Climate Forcers (SLCFs)

20. IPCC Established GWPs for SLCFs
IPCC AR5 report synthesizes the consensus science on GWPs for SLCFs.
Includes global average values for black and organic carbon, and regionally differentiated values for NOx.
Values for black carbon must be updated to account for regional variability in forcing.

21. Accounting for Regional Variability of Black Carbon
Accounting must consider the region of emission.
The GWP of black carbon can vary by 30% or more, based on the region of emission.
Radiative Forcing of Black and Brown Carbon (W/m2).
Source: Chung, C.E., V. Ramanathan, et al
The type of source of an emission is also very important.
The GWP for black carbon from biomass combustion is about 50% higher than the GWP for diesel fuel combustion.

22. Calculating Regional GWP Values for Black Carbon Using Consensus Science
Three radiative effects of black carbon:
“Direct” effect: darkened atmosphere absorbs more sunlight.
Snow and ice effects: darkened surfaces absorb more sunlight.
Cloud interactions: Cloud distributions, structure, and presence are altered by black carbon inside and outside the cloud.
Applying the framework, findings from consensus climate science undergo a data quality assessment to establish GWP values for black carbon.

23. The Importance of Sulfate Cooling
IPCC AR5 estimates that cooling from sulfates today masks 75% of the radiative forcing caused by CO2.
Since 1800, sulfate cooling has mitigated 30-50% of global warming.
It has masked more than 50% of the warming caused by the United States.

24. Tracking Global SO2 Emissions
2011: 85 million tons of sulfur emissions (MACEB, 2013)

25. Three Major Cooling Zones from Anthropogenic Sources (IPCC, 2001)

26. Changes in SO2 Emissions Over Time
Since 1980:
60% decrease in emissions in USA and Europe
300% increase in China
Source: Smith, et al

27. Mapping Trends: US Sulfate Cooling Zones have Dissipated
Regional Cooling = -4.0 W/m2
Regional Cooling = -1.0 W/m2
According to Harvard and NASA research (2011), this loss in sulfate cooling has raised regional mean temperatures by over +1oC.

28. Regional Cooling = -1.0 W/m2 Regional Cooling = -8.0 W/m2
LCA Characterization Modeling: Sharp Increase in the Chinese Sulfate Cooling Zone ( )
1978 Sulfate Cooling Zone
2008 Sulfate Cooling Zone
Regional Cooling = -1.0 W/m2
Regional Cooling = -8.0 W/m2

29. The Increase in Chinese Cooling was a Major Reason for Pause in the Rise of GMT (2000-2008)

31. Health Impacts Associated with Chinese Sulfate Cooling Zone
Trade-off: Lung cancer rates have doubled in China, and asthma now affects 30% of children in the region.

32. Implications of Dissipation of Chinese Sulfate Cooling Zone?
IPCC AR5 projections do not include significant reductions in SO2 emissions in China.
China is working to reduce emissions from coal power plants and other industries. Since AR5 was published, China has invested $350 billion to reduce SO2 emissions.
An unintended consequence would be an immediate increase in global forcing.

33. Establishing GFP Values for the Three Temperature Thresholds

34. Applying the Global Temperature Thresholds in Practice
The Global Warming Potential (GWP) equation, defined by IPCC, is used. Any one of three time horizons can be used, each with different implications:
1.5°C threshold: 20-year time horizon.
Use of this threshold focuses on near-term mitigation options, such as mitigation of short-lived climate forcers.
2°C Threshold: 35-year time horizon.
Use of this threshold focuses on mitigation options targeted at averting major irreversible climate change.
4°C Threshold: 100-year time horizon.
Use of this threshold focuses on mitigation of emissions of long-lived GHGs.

35. Basis of Global Forcing Potentials
The updated climate metrics are not based in original research.
IPCC AR5 Chapter 8 has metric values for all of the GHGs, most of which can be used without change. However, some of these values must be updated.
Establishment of GFPs is well- established in the peer- reviewed literature.
GFP values are based on published findings.
The climate metrics assimilate published data into a single unified framework.
Example data sources:
Chapter 8 of IPCC AR5
Collins, et al. (2013). Global and regional temperature-change potentials for near-term climate forcers. Atmos. Chem. Phys., 13, , 2013.
Shindell, D.T., (2009). Improved Attribution of Climate Forcing from Emissions. Vol. 326, Science, October 2009.
Joos, F., et al (2013). Carbon dioxide and climate impulse response functions for the computation of greenhouse gas metrics: a multi-model analysis, Atmos. Chem. Phys., 13, , doi: /acp , 2013.
Reisinger, A., M. Meinshausen, M. Manning, and G. Bodeker (2010), Uncertainties of global warming metrics: CO2 and CH4 , Geophys. Res. Lett., 37, L14707, doi: /2010GL
Bond, T. C., et al. (2013), Bounding the role of black carbon in the climate system: A scientific assessment, J. Geophys. Res. Atmos., 118, 5380–5552, doi: /jgrd
Bond, T., et al. Quantifying immediate radiative forcing by black carbon and organic matter with the Specific Forcing Pulse. Atmos. Chem. Phys., 11, , 2011.

36. Global Forcing Potentials by Temperature Threshold
Climate Forcer
+1.5°C threshold
(Next 20 years)
+2.0°C threshold
(Next 35 years)
+4.0°C threshold
(Next 100 years)
Carbon dioxide
From IPCC AR5 1
Nitrous Oxide
264
280
265
Methane
From Shindell 2009
104 73 32
SO2 -> Sulfate aerosols
From Collins, 2013
-313
-196
-85
Black carbon (U.S, energy)
From Bond 2011 and 2013
2,525
1,608
717
Black carbon (South Asia, biomass)
3,625
2,308
1,030

37. Updating the GWP of Methane
IPCC has updated the GWP for methane, including one additional effect.
The climate effects of methane are complex: Absorbs infrared radiation directly Effects plant growth On decay, forms ozone and CO2 Forms stratospheric water vapor Decreases sulfate aerosol cooling
Substance
GWP-20
GWP-100
Methane (IPCC AR5) 86 34
Commonly used GWP value (23) only accounts for one effect over 100 years
NASA scientists have assessed estimates including all other effects, resulting in even higher values.
Substance
GWP-20
GWP-100
Methane (Shindell 2009)
104 32
The metrics include all climate effects of methane for which accurate data is available.

38. Outputs of Updated Climate Metrics
Climate Forcing Profiles
Represents net forcing over the next 100 years
Measured in units of milli-Watts per square meter, in each year
Used to understand changes in radiative forcing over time
Through integration, can be used to calculate Climate Footprints
Climate Footprints
Evaluate the net integrated forcing out to one of the three GMT anomaly thresholds
Measured in units of kg CO2e
To be used as the basis of any LCA comparisons

39. Applying Climate Metrics to a Refrigerator
14 years of use in Georgia, US
477 kWh/yr.
Made in China

40. Refrigerator Climate Footprint Changes over Time
Coal power plant in Inner Mongolia
2035 Climate Footprint = 9,900 kilograms
2050 Climate Footprint = 7,900 kilograms
Emissions of short-lived forcers during manufacture
2100 Climate Footprint = 7,700 kilograms
Emissions of CO2 from use accumulate over 14 years
Long-lived gases remain in atmosphere for 100+ years
China is one of the world’s largest emitters of black carbon!
100+ years

41. Changes in Climate Footprint Based on Manufacturing Location
(kg CO2e)
Refrigerator
Made in China
Manufacturing
5,700
Use
(US-14 years)
4,200
Total
9,900
Refrigerator
Made in USA
800
4,200
4,900

42. American VS Chinese Manufacturing
(Based on 2035 Climate Footprint)
LCA Scope
(per 1,000,000 units)
Refrigerator
Made in China
(tons CO2e)
Made in USA
Manufacturing
5.7 million
0.8 million
Use
(US-14 years)
4.2 million
Potential Impact Reductions
Switching site of manufacture
5M tons
25% efficiency improvement
1M tons

43. Conclusions The updated climate metrics should include:
Factor in internationally-agreed upon maximum temperature targets.
Include all climate forcers, including black carbon.
Accurately account for the forcing effects of methane.
Account for effects from coolants.
Complete LCA information output: Calculating Climate Forcing Profiles and three changes in the Climate Footprint over the three critical time horizons.

44. Questions? Please Contact: Tobias Schultz, Life Cycle Assessment Practitioner
SCS Global Services