Markus Amann
International Institute for Applied Systems Analysis (IIASA)

Mitigation oflong- and short-lived climate forcers:

Co-benefits on non-climate policy objectives

RITE ALPS International Symposium
Tokyo, February 9, 2011

Rationale•

Co-control of CO2 and air pollutants results in significant co-benefits of
GHG mitigation on human health, ecosystems and agricultural pollution•However, accompanying reductions of cooling agents (SO2, OC)
compensate climate benefits from CO2 mitigation in the next few decades.

•Our study explored the scope for control of short-lived substances that
could complement efforts to reduce long-lived greenhouse gases andminimize the negative climate impacts of SO2 controls.

Co-control of GHGs and air pollutants
Annex I parties of UNFCCC, 2020

Source: IIASA GAINS
http://gains.iiasa.ac.atLow carbon strategies have significant co-benefits
on human health - in Europe and in Asia

CO2 emissions vs.
health impacts (YOLLs)

Low CO2 strategies result in lower damage to health andvegetation from reduced airpollution,
 cost savings for air pollution
control equipment,compensating for up to 40% ofGHG mitigation costs.

Change in CO2 emissions compared to baseline
0%-10%
20%-30%Change in life years lost compared to baseline
0%-30%-20%-10% less SO2, NOx and PMemissions,● EU-27● China● India

Source: IIASA GAINSCo-benefits of GHG mitigation on crop losses
in China

Change in crop loss due toground-level ozone
compared to 2005
Change in crop loss compared to 2005

25%

Rice:
crop loss
calculated
for 2030
baseline

20%

15%

10%

Wheat:
crop loss
calculated
for 2030
baseline

5%

0%
Maize

Rice

Business-as-usual 2030

Soybean

Wheat

Climate scenario 2030

Source: GAINS-Asia
http://gains.iiasa.ac.at

GHG mitigation reduces air pollution control costs
Costs to meet the EU air quality and climate targets (EU-27, 2020)

125
125

€/yr
BillionBillion €/yr

100100€20 bn/yr

75
755050252500

as usual
National energy
energyBusinessprojections(+3% CO2CO2 inin 2020)
2020)
National
projections(+3%Nationalenergy projections(+3% CO2 in 2020)

PRIMES energy
scenario
Illustrative projections
projections
meetingthe EUEU climate
climateIllustrative
meetingthewith climate
measurestargettarget(-20%(-20%CO2CO2in2020)2020)(-20%COinin2020)
2

Indicative costs
costs forfor changes
changes inin thethe energy
energy systemsystem toto meet
meet climate
climate andand energy
energy targets
targets
Indicative
Costs forfor further
further measures
measures toto achieve
achieve thethe targets
targets ofof thethe EU
EU Thematic
Thematic Strategy
Strategy onon Air
Air Pollution
Pollution
Costs
Costs forfor implementing
implementing current
current air
air pollution
pollution legislation
legislation
Costs

Source: IIASA GAINSWell-designed air pollution control strategies
can also reduce GHG emissions
but do they also mitigate climate change?

Emission control costs (% of GDP (PPP) in 2030)

Emission control costs for reducing PM health impacts in China by 50%
0.20%
PM controls,households
0.15%

PM end-of-pipe measures-8% CO2
0.10%

NOx end-of-pipe measures
SO2 end-of-pipe measures
Co-generation

0.05%

Energy efficiency, industry
Energy efficiency, households
Electricity savings

0.00%
Using only air
pollution controlmeasures

Using air pollution
control measuresand GHG measuressimultaneously

Source: GAINS-Asia
http://gains.iiasa.ac.atControl of CO2 is unlikely to reduce

temperature increase in the near-term

Global temperature 1900-2070
Reference scenario:
IEA World Energy Outlook 2009
CO2 measures:
IEA 450 ppm scenario 2009

Temperature increase in thenear-term is determined by:•CO2 in the atmosphereas a result of historicemissions of CO2Source: UNEP Black Carbon Assessment, forthcoming 2011

•Change in emissions ofshort-lived substances,
esp. co-control of SO2(leads to warming)‘Win-win’ air quality measureswith co-benefits on climate change

Radiative forcing from short-lived air pollutants:•Warming: BC, CO, O3 precursors (CH4, CO)•Cooling: SO2, OC•

Only little net effects: NOx, VOC

These substances are often co-emitted, and control measures affect severalsubstances at the same time.

Which air quality measures would also reduce radiative forcing?

Approach developed for UNEP/WMO BC Assessment

1. Compile literature values on radiative forcing/GWP for each substance

2. For each of 2000 air pollution control measures in GAINS,
estimate their impacts on CH4/BC/OC/CO/SO2/VOC/NOxemissions and their net effect on radiative forcing
3. Determine their mitigation potential for the baseline emission projection
4. Select the ‘top 15+ measures’ that reduce most SLCF forcing globally
5. Estimate their temperature impact with GCMs

Radiative forcing of GHGs and air pollutants
Literature ranges of GWP100

Mean value

Range

Reference

CO21

IPCC, AR4CH425

IPCC, AR416- 34

IPCC AR4CO

1.9

IPCC, AR41- 3

Range from AR3, citedin AR4VOC

3.4

IPCC, AR42- 7

IPCC AR4, ref. toCollins et al. 2002

BC680

Bond & Sun,2006

210- 1500

Bond & Sun, 2006

SO2-40Fuglestvedt etal., 2009-24- -56

Schulz et al. 2006,(±40%)

OC-69

Schulz et al.,2007-35- -104

Bond et al. (±50%)

NOx~0Net impacts of BC measures on integrated radiative forcing# of cases (out of 1000)

Monte-Carlo analysis for literature ranges of GWP

1000

Power generation

900

Brick kilns

800

Coke ovens

700

Woodstoves/pellets

600

Cook stoves/advanced
Coal stoves/filters

500
400

Diesel vehicles

300

Non-road
machinery200

Ban of agri. burning

100
0-0.3-0.2-0.1

00.10.2

Integrated radiative forcing (W/m2/yr)

0.3

Three groups of promising measures

CH4 measures

Technical BC measures

Non-technical measures

1. Recovery of coalmine gas

1. Modern cokeovens

1. Ban of highemitting vehicles

2. Production of
crude oil andnatural gas

2. Modern brick kilns

2. Ban of open
burning ofagricultural waste

3. Gas leakages atpipelines anddistribution nets

4. Briquettes insteadof coal for heating

4. Waste recycling
5. Wastewater
treatment

6. Farm-scale
anaerobic
digestion
7. Aeration of ricepaddies

3. Diesel particle
filters

5. Improved biomass
cook stoves
6. Pellets stoves andboilers (inindustrializedcountries)

3. Elimination ofbiomass cookstoves

Mitigation potentials in 2030

Emission reduction
relative to baseline in 2030

World, relative to baseline projection

0%-10%
-20%
-30%
-40%
-50%

-60%
-70%
-80%

-90%
-100%
CH4

Source: IIASA GAINS
http://gains.iiasa.ac.at

CONOx

VOC

PM2.5

BCOC

Other
PM2.5

Emission reductions fromthe chosen 16 measures

all other 2000 measures

SO2Difference in radiative forcing in 2030
from the chosen 16 measures

Source: UNEP Black Carbon Assessment, forthcoming 2011The 16 measures could significantly reduce the rate oftemperature increase in the next decades

Global temperature 1900-2070
Reference scenario:
IEA World Energy Outlook 2009
CO2 measures:
IEA 450 ppm scenario 2009

Near-term measures:
IIASA set of 16 measures
for CH4 and black carbon

Source: UNEP Black Carbon Assessment, forthcoming 2011

Together with aggressive CO2 strategies, they increasechances to stay below the 2º target

Global temperature 1900-2070
Reference scenario
IEA World Energy Outlook 2009
CO2 measures
IEA 450 ppm scenario 2009

Near-term measures
IIASA set of 16 measures
for CH4 and black carbon
CO2 + Near-term measures

Source: UNEP Black Carbon Assessment, forthcoming 2011

In addition to their climate benefits,
they also contribute to important development objectives

Source: UNEP Black Carbon Assessment, forthcoming 2011

Conclusions•Control of long-lived GHGs results in significant co-benefits on air pollution,including savings in air pollution control costs.

•Well-designed air pollution control strategies can also reduce CO2
emissions at no additional costs.

•However, SO2 controls might compensate the temperature benefits
from CO2 mitigation in the near-term.

•16 practical air quality measures could reduce radiative forcing from shortlived substances by about two thirds (especially in Asia) and lower global
temperature by about 0.5 degrees. Together with aggressive CO2strategies, they increase the chances to stay below the 2º target.

•These measures do not only improve local air quality, but also result insignificant benefits to development objectives.

•These measures are complementary to CO2 mitigation strategies,
but cannot substitute the urgency to control long-lived GHGs.