Four Scenarios, One Ranking
Wildfire contributes between 1.0 and 8.0 µg/m³ of PM2.5 depending on fire severity. We tested the full policy portfolio across four wildfire scenarios spanning this range to determine whether wildfire uncertainty could flip the optimal policy choice.
In every scenario, the top-ranked policy is T2 accelerated + B2 accelerated, followed by T2 accelerated alone. The winner is stable across all four scenarios; only the 6.5 µg/m³ extreme 2021 case produces one mid-list swap between two near-tied policies.
| Scenario | Wildfire PM2.5 | Baseline Deaths | Wildfire Excess | T2 Deaths Avoided | Ranking Changed? |
|---|---|---|---|---|---|
| Mild (2019-type) | 1.0 µg/m³ | 2,653 | 154 | 555 | No |
| Normal (5-yr avg) | 2.5 µg/m³ | 2,924 | 426 | 552 | No |
| Extreme 2021 (Dixie) | 6.5 µg/m³ | 3,763 | 1,265 | 542 | Mid-list swap* |
| Extreme 2020 (August) | 8.0 µg/m³ | 4,031 | 1,533 | 536 | No |
Deaths avoided shown for T2_accelerated (transport only). Rankings evaluated across all 13 single and combined policies. Year 2035 projections. *Extreme 2021 has one mid-list swap between two near-tied policies; top-ranked T2+B2 and T2_accelerated remain stable across all four scenarios.
Wildfire Changes the Magnitude, Not the Ranking
As wildfire PM2.5 increases from 1.0 to 8.0 µg/m³, the absolute number of deaths avoided by each policy decreases slightly. This is because a higher wildfire baseline means the marginal impact of transport and building emissions is diluted — the same ton of NOx removed has a slightly smaller relative effect on total PM2.5.
The marginal value ratio measures how much wildfire dilutes the effectiveness of electrification policies. Even in the extreme 2020 scenario, the ratio is 0.963 — policies retain 96% of their effectiveness. The top-ranked winner (T2+B2) never changes because wildfire affects all policies nearly proportionally.
Wildfire is a health problem, not a policy-ranking problem. An extreme wildfire year adds 1,533 excess deaths to the baseline. That is a massive public health burden. But it does not change which electrification policy you should choose — because wildfire affects the denominator, not the relative ordering of interventions.
4 wildfire scenarios (1.0–8.0 µg/m³) · 13 policy combinations · 2035 projection year · ISRM source–receptor matrix · Dual CRF (Di + Krewski) · Marginal value ratio = deaths avoided (with wildfire) / deaths avoided (without wildfire)