Two innovative smart city examples for protecting cities from heat waves

Rather than being the end of the world, it’s more the beginning of the realization of the harmful environmental impact that human beings have on the planet. The 21st century saw the beginning of laws, innovations and best practices which help protect humans from climate risks. Heat waves have become a priority, and have been since 2003.

Far from the idea of the author going into apocalyptic or dystopic scenarios, the temperatures of  the summer of 2019 will have left their mark on history. Thursday, July 25 was a record-breaking day (according to Météo France):

  • 42,6° in Paris (which broke its record from 1947)
  • 48° in Greece (a European record)
  • Anchorage, Alaska recorded its 2nd hottest June ever with a high temperature of 32° (the average for July is normally 3.4° at this latitude).
  • 8° was recorded in Churu, in northern India, on June 1st.
  • 38° in Prague
  • 44° in Girona, Spain
  • 37° in New York, with a 43° heat index on Sunday, July 21, 2109


The planet has experienced its hottest period in 2,000 years. Météo France estimates that these temperatures were equivalent to “the average maximum temperature in Baghdad in July”. Moreover, the frequency of heat waves would most likely double by 2050.

Indeed, temperatures will be around 50°C, and the world’s population will reach 9.8 billion, 66% of whom will live in urban areas (2014 United Nations Report).


To protect yourself from heat waves, go green!

Do you remember your 8th grade Life Science classes?

If you don’t recall the principle of photosynthesis, here’s a reminder: plants have the ability to transform CO2 into organic carbon and to restore oxygen to the atmosphere.

From this observation was born the concept of bionic architecture, i.e. the greening up of buildings with two objectives:

  • to Isolate buildings and create cool zones by absorbing heat
  • to re-oxygenate the air by absorbing C02 from the atmosphere

All these initiatives are great, according to Vincent Callebaut, a specialist in this domain. He’s known for publishing a study called “Paris Smart City 2050” in 2015 in which he proposed transforming the Tour Montparnasse into a “58 story vertical Central Park“.

From individual cultivation of vegetable gardens on balconies to community gardens and urban greenhouses…all these contribute to the bio-air conditioning of cities at a lower cost.

Paris is planning to plant 100 hectares of rooftops, facades and neglected urban areas (i.e. vacant lots)  by 2020. The French capital is even planning to use 1/3 of this for growing fruits and vegetables. 

Such as Cueillette Urbaine, a French start-up, whose aim is creating a “inclusive kitchen garden” on the roofs of your offices.

In addition to working on team spirit, this city farm develops locavore consumption of natural agricultural products while improving the living environment of population through the greening of urban space.

Cueillette Urbaine has 9 of the 17 Sustainable Development Goals of the UN.

Ground coverings, a domain that remains uncertain

Defeating urban heat islands is essential for compensating for the phenomenon of record-high temperatures. Striking cities, this term refers to the concentration of heat around large urban areas. According to Le Monde, it’s 2.5°C warmer in Paris than in its rural suburbs, knowing that the temperature can increase by 10-12° more during the night.

However, contrary to what one might think, heat in cities doesn’t just come from buildings. Indeed, the ground is a constant concern, as asphalt retains heat. As such, the paving of streets prevents the temperature from falling, even at night.

A solution: albedo, or the cooling power of the earth from the reflection of a surface exposed to light. These special coatings reflect solar radiation directly back to the sky rather than to buildings.









In Los Angeles, the process has already borne fruit. This white road surface technique has lowered the temperature by 10° in some areas of Jordan Avenue, one of the hottest areas in the city.

Quimper also tested this innovation in 2015. Leclerc supermarket in that area has covered their 7,000 m² roof with white reflective paint. Today, the Breton store is the largest “cool roof” in all of Europe. According to Le Moniteur, Leclerc claims to have reduced its temperature by more than 20°C and has achieved an annual electricity savings of €20,000 (in terms of air conditioning), not to mention the reduction in greenhouse gas emissions by the equivalent of more than 175 tons of CO2.


Caring is sharing

But the question remains: will these positive energy buildings have the ability to limit the additional greenhouse effect that’s responsible for these significant temperature increases?

Only time will tell. The beginning of the 21st century is marked by a world-wide awareness. We must accept being in this transitional phase – that the means put in place are only at the experimental stage.

But before thinking about the impact of smart city projects on heatwaves, we also need to talk about prevention!

Don’t forget to hydrate regularly, and remind your family and friends to do the same!

To read: Paris, a resilient city