Urban Heat Island Effect

Most climate change impact studies are qualitative and don't take into account that large cities will experience additional warming due to the urban heat island effect—defined as the change of local climate patterns caused by urbanization.

Urbanization Data Points

Picture of Earth from space


  • Cover about 1% of Earth's surface.
  • Home to over 1/2 the human population
  • Produce 80% of GWP (gross world product)
  • Consume 78% of the world's energy
A map of Urban Heat Islands in the USA showing temp differences from cities and rural lands

Between 1950-2015

  • 27% of cities and 65% of urban population warmed more than the world average
  • 60% of that urban population experienced warming twice as large as the world (about 0.6 C)
  • This effect could add 2 C to warming for the most populated cities by 2050

Nature Climate Change 7, 403-406 (2017)


Changing 1/5th of a cities' roofs and 1/2 the pavements to "cool" versions could save twelve times the cost of installation and maintenance while reducing air temperatures by an average of 0.8 C.

Nature Climate Change 7, 403-406 (2017)