Future life in extremely hot climate

Four degrees are what scientists predict the temperature will rise in the Middle East by mid-century[i] – twice the global average. Record temperatures have already reached beyond 50 degrees. What sounds like just a bit hotter than before actually is much worse: from certain temperatures even the healthiest people cannot be outside any more because the human body cannot cool itself any more through transpiration. The higher the humidity, the lower that threshold is. This means that the coastal zones of the Red Sea and the Arab/Persian Gulf become death zones for sustained periods of time.

The life support system that allow us to survive exists – air conditioning. But that comes at a price: cooling air requires a lot of energy, and – when powered by fossil fuel – pollutes the air to levels that – combined with the heat induced sand storms – also will require air filtering to survive. It seems almost inevitable that people will have to live like in a space station for parts of the year with any outside major activity, from recreation to consumption to construction, coming to a grinding hold. In some ways the life will not differ much from the life we all remember from the times of the lockdowns during the Covid epidemic, alone this time without the perspective of the root cause disappearing at some point in the near future.

One could argue that – since this seems unavoidable – one better builds a space station right ahead, and some of the futuristic projects under development visually resemble outer space habitat, but fortunately also in the future there will be times when life outside is perfectly possible and pleasant – a condition we should seek to extend for a maximum period of time throughout the year.

We can achieve that, if we design differently. It comes as a surprise that very little attention seems to go into achieving that. Take a city like Riyadh, where in most places any principle of climate adaptive design has been forgotten in the omnipresence of air conditioners. The striking thing is, that there is ample experience in creating more comfortable climatic environments without the breeze of cool air coming out of an air duct. Alone – it seems to me that locals consider it outdated because it does not use a lot of technology. These low-tech solutions are called: Shadow and Wind. Does this sound simple? It is. But why don’t we use it then as a design principle?

Shadow, especially when combined with planting, can reduce outside heat significantly. Temperatures under a shadowy tree can be 40% lower than on a car park in the sun[ii]. In many countries, regulations require a certain degree of sunlight in every residential unit planned. I am not aware that the opposite – a degree of shadow –  exists. It would not be a big challenge to turn this into regulatory policy. We also should come up with public space design guidelines that mandate a certain amount of shadow and, especially when entire districts are planned and built, the overall massing could be used to optimize shadow casting. If the dominance of the car would be reduced in these areas, then the overall urban fabric could move closer together and have relatively more shadowed spaces. Air flows can further increase the comfort of these shadowed spaces. If wind speeds are not too high, even the hottest breeze feels refreshing because the resulting increased evaporation of sweat helps to cool the body. We can optimize our buildings to trigger air flow in and in between them. High-rise buildings not only cast big shadows but also force air to move around them, increasing wind speeds that are that pleasant breeze. But this principle does not only apply to high-rise. It can be used in low rise too, as the traditional wind towers across the Arab peninsula show.

If urban design and planning in these places would embed these principles into the local regulatory frameworks, then not only less energy would have to be spent on creating comfortable conditions and cleaning the air, but many other qualities could also thrive. A shadow casting and air flow promoting urban fabric typically is more compact and therefore more suitable for walking and other slow forms of movement. Shadow and breeze promoting architecture can be more porous and open than the sealed refrigerators, air-conditioned buildings tend to be. The result can be a livelier public space with active frontages and places for a wide range of outside activities.  

Shadow and wind will not lead to an urban fabric that feels comfortable 365 days a year but in the light of being confined to the indoors for substantial amounts of time in the near future, expanding the time we can spend in the great outdoors seems a goal imperative for our physical, social and economic wellbeing.

Having the chance to escape the sound of the airco for as long as possible, therefore, is more than just a pleasant outdoor experience question. It is a fundamental question in the quest for a better quality of life in cities, Saudi Arabia and other countries in the region want and have to achieve to secure a lasting post fossil future.

[i] https://www.mpg.de/10856695/W004_Environment_climate_062-069.pdf

[ii] https://eu.desertsun.com/story/opinion/contributors/valley-voice/2022/04/09/coachella-valleys-asphalt-synthetic-lawn-heat-islands-reach-170/9515857002/

Cover image: Section through a neighbourhood optimized for shade and air movement (c) MLA+

Text by Markus Appenzeller