Loss of air filtration

Loss of air filtration

Plants and the ecosystems around a site capture airborne pollutants and fix them. When that vegetation degrades, a site whose activity needs clean air has to filter it itself. Resilience books that loss as a Business interruption loss, against revenue only.

What the map shows

Air filtration has no layer of its own. ENCORE links it to Species and Habitats only, not to Atmosphere:

• Today: Species: MSA Degradation (2015). Habitats: Natural habitat % — baseline 2024 (LUH3), a layer hidden from the map pickers and shown under Today.
• Projected: Species: MSA Shock layers for SSP1 and SSP3. Habitats: LUH3 Shock layers, trajectory M for SSP1 and H for SSP3. Both at 2035, 2050 and 2080. SSP2-4.5 reads the SSP3 layers.

Both suppliers weigh 1 in forests and woodlands, shrublands, savannas and grasslands, urban areas and palustrine wetlands. They weigh 0.5 in most other biomes and 0 in subterranean ecosystems. A site spanning several biomes keeps the highest weight. At each site the service takes the most degraded supplier, after its delivery weight.

How the loss is computed

The degradation D, between 0 and 1, is the largest of (delivery weight × degradation of the natural asset) at the site. The dependency is the ENCORE rating of the site's activity, read as (rating − 1) / 4. No replacement cost is published for this service yet, so the loss is D × dependency × revenue. See Nature risks and Shock layers.

Sources

• GLOBIO 4 (PBL), Schipper et al. (2020): Mean Species Abundance. CC BY 4.0.
• Land-Use Harmonization 3 (LUH3), University of Maryland, CMIP7 (Zenodo / input4MIPs); HYDE 3.4 land-use reconstruction. LUH3: CC BY 4.0. HYDE 3.4: Licence not confirmed (CC BY 4.0 reported).
• ENCORE 2024 (Global Canopy, UNEP FI, UNEP-WCMC): delivery weights and dependency ratings. CC BY-SA 4.0.

Limits

• The PM2.5 layers do not feed this risk: ENCORE gives air filtration no Atmosphere link.
• LUH3 runs one model per trajectory (M is IMAGE, H is GCAM), so part of the gap between scenarios is a model gap. Trajectory M is current policies, not Paris-compatible.
• MSA never reads intact: GLOBIO's climate pressure puts the least disturbed land at about 8 % degradation.