From Models to Decisions

Amir Hakami

Carleton University

For Life and Breath May 1, 2014

Where do models fit?

• Emissions are the only variable we can control.– Use models to provide Policymakers with tangible “decision metrics”.

Emissions

MeteorologyPollution

Health Outcome

Transport and Transformation

Exposure

Health Influences

For Life and Breath May 1, 2014

Improving air quality

• Reducing emissions is costly.

• Assessing the benefits of emission reductions in terms that are comparable with costs (i.e., monetized) enhances the decision-making process.

• What is the cost of action vs. inaction?

For Life and Breath May 1, 2014

Benefit from one average vehicle

• Value for Toronto and coastal California: $400-$800/yr• Estimated benefit from the Toronto subway: $130,000,000/yr

NB: A fraction of benefits (non-fatal, long-term, or PM effects not included)Pappin and Hakami, 2013

For Life and Breath May 1, 2014

Health benefits: marginal benefit/damage

Mobile sources Point sources

• What the numbers mean?• Marginal benefits are key decision parameters.

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Health benefits are substantial

Abatement costs Health damage

Marginal benefits and costs of NOx emission reductions from power plants in the US.

Mesbah et al., 2013

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Bonus: increasing benefits with controls!

1 0.8 0.6 0.4 0.2 010000

15000

20000

25000

30000

35000

Point and mobile sources emission reduction (fractional)

Mobile Sources

Point Sources

For Life and Breath May 1, 2014

Next steps for air quality scientists

• Facilitate integrated assessment.– Enhance our communication skills with

other disciplines.

• Quantify/reduce various uncertainties in our understanding of processes that affect air quality.– Uncertainty is not a justified reason for

inaction.

For Life and Breath May 1, 2014

Next steps for air quality scientists - II

McRae and Cass (1981)Air quality model

Dec

isio

n m

odel

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Next steps for air quality scientists - III

Air quality model

Dec

isio

n m

odel

For Life and Breath May 1, 2014

Comments/questions

Thank you!

Funding provided by NSERC, CIHR, Environment Canada, Health Canada

For Life and Breath May 1, 2014

Rate of change in marginal damage

$

Marginal cost

Marginal damage

Emission level

New optimal level