Urban tree planting to maintain outdoor thermal comfort under climate change: The case of Vancouver's local climate zones

Mehdi Aminipouri, David Rayner, Fredrik Lindberg, Sofia Thorsson, Anders Jensen Knudby, Kirsten Zickfeld, Ariane Middel, E. Scott Krayenhoff

Research output: Contribution to journalArticle

7 Scopus citations


Spatiotemporal variation of mean radiant temperature (Tmrt), a major driver of outdoor human thermal comfort, is driven by exposure to solar and longwave radiation, which in turn respond to local patterns of shading, wind speed, air humidity and air temperature. In this study, the SOlar and LongWave Environmental Irradiance Geometry (SOLWEIG) model was used to simulate how changes in minimum and maximum air temperature and solar radiation under Representative Concentration Pathways (RCP) 4.5 and 8.5 climate projections would change Tmrt in Vancouver over the 2070–2100 period. With micrometeorological variables representative of a changed climate, days with Tmrt above 65 °C were predicted to increase three-to five-fold under RCP 4.5 and 8.5, respectively. SOLWEIG was also used to quantify the potential of maximum feasible street tree cover to reduce Tmrt for the hottest day on record for Vancouver (July 29, 2009), and an end-of-century hot day under the two future climate scenarios. SOLWEIG simulations with maximum feasible street tree cover under RCP 4.5 demonstrated an average reduction of 1.3 °C in Tmrt, compared to the contemporary extreme heat day with current street trees. However, average Tmrt increased by 1.9 °C under the RCP 8.5 scenario even with maximum feasible street tree cover, relative to the contemporary extreme heat day. We conclude that adding street trees has the potential to offset Tmrt increases under the RCP 4.5 scenario, however this measure is insufficient to maintain contemporary Tmrt under the RCP 8.5 scenario.

Original languageEnglish (US)
Pages (from-to)226-236
Number of pages11
JournalBuilding and Environment
StatePublished - Jul 2019



  • Extreme radiant thermal exposure
  • Heat mitigation
  • Local climate zones
  • Mean radiant temperature
  • Street trees

ASJC Scopus subject areas

  • Environmental Engineering
  • Civil and Structural Engineering
  • Geography, Planning and Development
  • Building and Construction

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