Skip to content
Scenario Analyses
06 / 10 Chronic physical full-depth

Extreme heat

Heat stress on people, processes and assets, indexed across scenarios and horizons.

The question it answers

Where will heat stress most affect our workforce, processes and equipment, and how fast does that intensify under each scenario?

What it does

Screening extreme heat across a portfolio

  • Screens assets for heat stress using temperature extremes, humidity-aware heat index and accumulated heat.
  • Indexes those measures into a single comparable band.
  • Projects the band across SSP scenarios and horizons.
How it works

Inputs in, banded result out

The governed model combines the inputs below into a single banded, scenario-aware result, under formal version and change control.

Inputs

  • Annual maximum temperature (TXx)
  • Heat index / days above 35°C (HI35)
  • Hot-degree-days

Governed model

Extreme heat

Anchored to public, peer-reviewed climate science.

Version and change controlled

Outputs

  • Asset heat band
  • Scenario–horizon trajectory
  • Portfolio roll-up
Inputs & sources

What goes in, and where it comes from

  • Annual maximum temperature (TXx)

    CMIP6

    The peak-temperature signal.

  • Heat index / days above 35°C (HI35)

    CMIP6 (temperature + humidity)

    Humidity-aware heat stress relevant to people and processes.

  • Hot-degree-days

    CMIP6

    Accumulated heat over the year — the chronic, cooling-load dimension.

Scenario assumptions

The futures we test

  • Each heat measure is read per SSP scenario and horizon.
  • Both peak heat and accumulated heat contribute, so a hot-but-short climate bands differently from a persistently warm one.
  • The result is indexed to a comparable axis rather than reported as raw temperatures.
Method

How the result is built

  1. Read peak temperature, heat index and hot-degree-days at the asset cell for each scenario and horizon.
  2. Index each measure onto a common scale.
  3. Combine into a composite heat-stress score.
  4. Band on the shared physical-risk axis.
Outputs

What you get back

  • Asset heat band

    Heat-stress exposure at screening resolution.

  • Scenario–horizon trajectory

    How heat stress intensifies over time.

  • Portfolio roll-up

    Heat exposure aggregated across the asset base.

  • Low
  • Medium
  • High

Heat trajectory fan across scenarios

The spread between SSP1-2.6 and SSP5-8.5 widens with time — heat is where scenario choice bites hardest.

Baseline203020402050
SSP1-2.6 SSP2-4.5 SSP3-7.0 SSP5-8.5
Interpretation

How to read the band

  • Heat is a chronic hazard: the trajectory matters as much as the baseline band, because exposure compounds year on year.
  • The scenario fan widens markedly by 2050 — heat is one of the clearest places where the emissions pathway changes the answer.
  • Translate a High band into operational questions: cooling load, outdoor-work limits and equipment derating.

Disclosure relevance

  • IFRS S2 Chronic physical risk identification (heat).
  • IFRS S2 Strategy resilience under multiple warming pathways.
  • TCFD Chronic hazard metrics across the asset base.

Limitations

  • Screening scope: not a thermal-comfort, productivity or equipment-engineering model.
  • Local cooling, shading and adaptation are not represented.
  • 0.25° inputs smooth urban heat-island effects that can dominate at city scale.

Screening-level analysis; not investment or engineering advice.

Bring extreme heat screening to your portfolio

Screened, banded and framed for IFRS S2 and TCFD disclosure.