Two Birds with One Stone? Urban Air Pollution and Climate Change

15.023 Lecture March 31st, 2004 Marcus C. Sarofim

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• effects, not visible.

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• impact, visible.

Two Problems

Climate Change Rising Temperatures Sea Level Rise Changing Weather Nonlinearities

Thermohaline Circ. Ice Sheet Collapse Methane hydrate release

Long timescale, global

Urban Air Pollution Millions of Deaths Severe Health Impacts

– Acid Rain Agricultural Damage

Short time scale, local

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Can we leverage local air pollution reductions to gain global benefits?

Percentage of emissions from fossil fuel sources

One Source?

Fossil Fuels

Other Climate/Pollution Interactions

• cycles may impact local air pollution

•

• – (aerosols, cooling)

• Both a GHG and a pollutant

Increased temperature and change in hydrological

Air pollution may in turn affect local temperature and hydrological cycles (see Arnico’s lecture) “Climatically important substances”:

black carbon (warming), SOx Ozone:

Three Philosophies

• Climate first! nd Assessment Report

• Optimal cost-benefit anal. rd Assessment Report

• Health first!

“Ancillary Benefits”: – IPCC 2

“Co-benefits”: – IPCC 3– Many economists

“Ancillary Benefits II”: – World Bank – Political Expediency

Working Group and Cifuentes Study

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2

true? –

BASELINE) – 10% of vehicles

produce > 50% of pollution. •

Assumptions: What is the increased mortality rate due to PM2.5

– CO and PM emissions are proportional for a given fuel source (fuel switching is much of the benefit) – is this

What are the BAU emission control technology assumptions? (ALWAYS THINK ABOUT YOUR

Ignored the function of gross emitters:

Climate first scenarios

Air Pollution Health Impact Evidence

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Long Term Epidemiology – Six Cities Study – Pope et al. (ACS) – HEI reanalysis of above studies

Natural experiments – Atlanta (Olympics) – Salt Lake City (Steel plant shutdown) – London Killer Fog

Where are the potential benefits?

Lancet/WRI study Include ancillary benefits in cost/benefit studies?

Courtesy of World Resources Institute, Washington DC. Used with permission.

Ancillary Confusion (IPCC WG3 summary)

Courtesy of the Intergovernmental Panel on Climate Change. Used with permission.

Increasing Resolution

Bangkok, Krakow, Manila, Mumbai, Santiago, Shanghai $20/ton carbon

1999

Figure 1- Sectoral contribution to local and global damages: Average for the six cities. Figure 2 – Fuel composition of local and global damages: Average for the six cities.

Lvovsky and Hughes, Environmental Challenges of Fuel Use, in "Pollution Management in Focus," Discussion Note Number 7, Dec.

http://www-wds.worldbank.org/servlet/WDS_IBank_Servlet?pcont=details&eid=000094946_00081005311068

The Diesel Story •

emit 25 to 400 times more soot. –

high gasoline taxes. Could GHG control lead to more diesel use and therefore more air pollution?

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conversion might actually lead to global warming, if black carbon is an effective greenhouse substance. (controversial)

– definitely cleaner.

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Diesel is ~30% more efficient than gasoline, but

Europe uses a lot more diesel, perhaps due in part to

Caveats: Jacobson’s work implied that gasoline to diesel

Natural gas may be more efficient than diesel, and

Better technology will lead to cleaner diesel vehicles

Structural and Other Options • •

– directly impacts indoor pollution!

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economy)

Reduce Transport (kilometer miles driven) Reduce Energy Demand

Insulating houses can reduce need for indoor heating:

Consumption reduction vs. improved technology?

Reforestation to reduce erosion Sectoral shifts (e.g. heavy industry to a service

Complications

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VOC sensitive • • •

NOx vs. VOC sensitive regions: – Mexico City, Atlanta: NOx sensitive. – LA:

Indoor pollution vs. outdoor Value of Health vs. Global Climate? Policy creation - international cooperation?

Political Issues

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• 2 trading

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CDM and Additionality – Costa Rica and the Private Forestry Project

Interaction with other policies – eg SO

Policy implementation – eg vehicle maintenance and inspection

Perverse effects – eg Hoy no Circula or new vehicle regulations

Conclusions •

solution between local and global benefits: •

solutions with the most benefit will be difficult… •

between industrialized and developed nations – like CDM, but more targeted towards “two birds

project level solutions.

There is definitely the potential for a win-win

However, crafting policies to encourage those

These policies should involve collaboration

with one stone” and structural level rather than

Bonus Slides

Interactions schematic

Diesel Story II Bus Type PM GHG Other

Diesel 1 1 1

Diesel (ultra low sulfur) .5 1 1

CNG (lean burn condition) .1-.2 >1? 3x CO, HC, 0.5 NOx?

Hybrid Diesel (300 ppm) .3-.5 .6-.9 0.3 CO, .6-.7 NOx

<.1 .6-.9 0.3 CO

How clean can diesel get? Is CNG more efficient than diesel or not?

(Stationary sources: yes, Mobile Sources: no?)

(300 ppm sulfur)

Hybrid (ultralow sulfur)

• Clean Development Mechanism •

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any that would occur in the absence of the certified project activity”

Kyoto Protocol

Article 12: Measurability: – “Real, measurable, long-term”

Additionality – “Reductions in emissions that are additional to

Particulates •

– 2, NOx, NH3 –

use in roof and road repair) •

– 70% biomass burning (concentrated in South America, Sub-Saharan Africa, India + SE Asia)

– China)

Total Suspended Particulates (TSP) • PM10 • PM2.5

Often secondary product of VOCs, SOOften area (non-inventoried) sources (cooking meat, tar

Global Black Carbon emissions:

30% industrial emissions (concentrated in Europe +

Two Impact Substances

• – BC = .5 to 1 W/m2 (IPCC: 0.1

to 0.4), ozone =0.4 to 0.6 W/m2 and both are direct greenhouse substances and air pollutants.

4: –

increasing ozone concentrations.

2, HNO3: – however, it

plays a role in offsetting global warming.

Black Carbon, Ozone: Jim Hansen hypothesis:

• CHIs a GHG, but reacts with OH radical thereby indirectly

• SONegative acid rain and respiratory impacts: