How can you build a city fit for a 50℃ heatwave?

It's not clear Dubai's golf courses can survive climate change. Image: Getty.

The Persian Gulf is already one of the hottest parts of the world – but by the end of the century increasing heat, combined with intense humidity, will make the region too hot for habitation, according to research published in Nature Climate Change.

Heating and air conditioning currently permit humans to live everywhere from Siberia to the Sahara. However the extreme heatwaves predicted for the Gulf, where temperatures will regularly hit 50℃ or even 60℃, will reach the limits of the thermal adaptation that buildings can provide.


Our ancestors lived without the sophisticated thermal control systems we typically use in modern buildings; they implicitly used different “bioclimatic designs”, such as natural ventilation or south-facing windows, and these skills are still valuable in many climates today. But the latest data suggest this will not be enough.

So is there a future for habitation in the hottest regions of the world? It seems mass migration is less likely than staying put and taking on the challenge.

However, figuring out how to live comfortably and sustainably while it’s hot enough to fry an egg on the sidewalk may provide a fillip for environmentally sensitive design and urban development throughout the world.

Living with intense heat

The climate is a problem but does offer some opportunities. The amount of sunshine available means there should be no shortage of solar electricity, though we need to develop efficient storage systems too. We could also take advantage of day-to-night ambient temperature variations using “thermal mass” techniques to even out temperature fluctuations.

Dino-architecture? Bahrain’s World Trade Centre is covered in glass. Image: AFP/Getty.

We will have to make significant changes to building design – highly glazed structures that soak up heat will become architectural dinosaurs. Traditional ideas from hot regions of the world will resurface: thick walls giving thermal stability (but enhanced with smarter materials such as composites with layers of insulation or perhaps embedded “phase-change” materials), used together with small windows. Building surfaces will need to be coated with smart materials that reflect heat gain – these already exist, and researchers have looked at their perfomance in the hot summers of cities such as Athens.

We’ll need to optimise where and when we occupy buildings, to seek out the coolest spots and take advantage of less intense night time conditions. We may find ourselves living partly underground in order to benefit from lower and more stable temperatures to be found a few metres below the Earth’s surface.

In intense heat, finding some shade becomes essential. Buildings, streets, services and even entire transportation systems need to be entirely shaded or even fully underground. Some of these features are already showcased in the Masdar City development in Abu Dhabi, though the project (which had significant design input from Norman Foster and partners) is not yet fully operational.

Switch on the air con industry

We can expect an air conditioning boom, too. This will cost a lot both to build and to operate, and we’ll have to come up with systems specially designed for extreme temperatures. The thermodynamics of current designs which rely on temperature differences between heat absorption and heat rejection mean it would be very difficult to achieve sufficient and efficient heat removal as these change and narrow.

In Dubai even the bus stops are air conditioned. Image: Jay Galvin, CC BY.

One opportunity would be to use the Earth or the sea/rivers as “heat sinks”, rather than the external air: these will be at lower temperatures and have the ability to absorb the heat, though perhaps with as yet unknown long term effects. It is also likely that air conditioning might most effectively be used during the night-time to pre-cool the building; night-time air temperatures will allow more efficient refrigeration.

Urban design and the ways in which cities are used at time of extreme heat will also need to be considered. Moving around outdoors without protection could become as unimaginable as walking unprotected from a polar research station in winter.

This obviously causes significant problems for those who must work outside: places of refuge may need to be constructed, and the very act of building may need to be restricted to the “winter” (or rather, slightly cooler) months. Construction products will also be obliged to change in order to cope with more extreme thermal stresses and expansion effects.

Heatwave cities

The shape of cities and the massing of their major buildings will change so that groupings offer a degree of self-protection. Streets will be designed to optimise shading and, when available, cooling air ventilation. The spaces between buildings will need to be carefully designed and uses (such as what might happen underground) considered alongside services provided to citizens. Shopping malls could be submerged and used as links between areas, just as the underground streets found in northern latitude cities like Montreal are used in winter.

Cities themselves may shift away from coastal to inland zones due to the problematic combination of high temperatures with high humidities near to water masses. In drier atmospheres, technologies such as evaporative cooling (in their simplest form, fountains and water sprays) can be used to reduce temperature.

A technological alternative to this might be the use of moisture absorbing materials (regenerated desiccants) to dehumidify the atmosphere, but this would be a significant and complex task on the scale required. Moving whole cities can only be a long term plan – but it is something worth thinking about now, while there is time.

Adrian Pitts is professor of sustainable architecture at the University of Huddersfield.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

12 things we learned by reading every single National Rail timetable

Some departure boards, yesterday. Image: flickr.com/photos/joshtechfission/ CC-BY-SA

A couple of weeks ago, someone on Twitter asked CityMetric’s editor about the longest possible UK train journey where the stations are all in progressive alphabetical order. Various people made suggestions, but I was intrigued as to what that definitive answer was. Helpfully, National Rail provides a 3,717 page document containing every single timetable in the country, so I got reading!

(Well, actually I let my computer read the raw data in a file provided by ATOC, the Association of Train Operating Companies. Apparently this ‘requires a good level of computer skills’, so I guess I can put that on my CV now.)

Here’s what I learned:

1) The record for stops in progressive alphabetical order within a single journey is: 10

The winner is the weekday 7.42am Arriva Trains Wales service from Bridgend to Aberdare, which stops at the following stations in sequence:

  • Barry, Barry Docks, Cadoxton, Cardiff Central, Cardiff Queen Street, Cathays, Llandaf, Radyr, Taffs Well, Trefforest

The second longest sequence possible – 8 – overlaps with this. It’s the 22:46pm from Cardiff Central to Treherbert, although at present it’s only scheduled to run from 9-12 April, so you’d better book now to avoid the rush. 

  • Cardiff Central, Cardiff Queen Street, Cathays, Llandaf, Radyr, Taffs Well, Trefforest, Trehafod

Not quite sure what you’ll actually be able to do when you get to Trehafod at half eleven. Maybe the Welsh Mining Experience at Rhondda Heritage Park could arrange a special late night event to celebrate.

Just one of the things that you probably won't be able to see in Trehafod. Image: Wikimedia/FruitMonkey.

There are 15 possible runs of 7 stations. They include:

  • Berwick Upon Tweed, Dunbar, Edinburgh, Haymarket, Inverkeithing, Kirkcaldy, Leuchars
  • Bidston, Birkenhead North, Birkenhead Park, Conway Park, Hamilton Square, James Street, Moorfields
  • Bedford, Flitwick, Harlington, Leagrave, Luton, St Albans City, St Pancras International

There is a chance for a bit of CONTROVERSY with the last one, as you could argue that the final station is actually called London St Pancras. But St Pancras International the ATOC data calls it, so if you disagree you should ring them up and shout very loudly about it, I bet they love it when stuff like that happens.

Alphabetical train journeys not exciting enough for you?

2) The longest sequence of stations with alliterative names: 5

There are two ways to do this:

  • Ladywell, Lewisham, London Bridge, London Waterloo (East), London Charing Cross – a sequence which is the end/beginning of a couple of routes in South East London.
  • Mills Hill, Moston, Manchester Victoria, Manchester Oxford Road, Manchester Piccadilly – from the middle of the Leeds-Manchester Airport route.

There are 20 ways to get a sequence of 4, and 117 for a sequence of 3, but there are no train stations in the UK beginning with Z so shut up you at the back there.

3) The longest sequence of stations with names of increasing length: 7

Two of these:

  • York, Leeds, Batley, Dewsbury, Huddersfield, Manchester Victoria, Manchester Oxford Road
  • Lewes, Glynde, Berwick, Polegate, Eastbourne, Hampden Park, Pevensey & Westham

4) The greatest number of stations you can stop at without changing trains: 50

On a veeeeery slow service that calls at every stop between Crewe and Cardiff Central over the course of 6hr20. Faster, albeit less comprehensive, trains are available.

But if you’re looking for a really long journey, that’s got nothing on:

5) The longest journey you can take on a single National Rail service: 13 hours and 58 minutes.

A sleeper service that leaves Inverness at 7.17pm, and arrives at London Euston at 9.15am the next morning. Curiously, the ATOC data appears to claim that it stops at Wembley European Freight Operations Centre, though sadly the National Rail website makes no mention of this once in a lifetime opportunity.

6) The shortest journey you can take on a National Rail service without getting off en route: 2 minutes.

Starting at Wrexham Central, and taking you all the way to Wrexham General, this service is in place for a few days in the last week of March.

7) The shortest complete journey as the crow flies: 0 miles

Because the origin station is the same as the terminating station, i.e. the journey is on a loop.

8) The longest unbroken journey as the crow flies: 505 miles

Taking you all the way from Aberdeen to Penzance – although opportunities to make it have become rarer. The only direct service in the current timetable departs at 8.20am on Saturday 24 March. It stops at 46 stations and takes 13 hours 20 minutes. Thankfully, a trolley service is available.

9) The shortest station names on the network have just 3 letters

Ash, Ayr, Ely, Lee, Lye, Ore, Par, Rye, Wem, and Wye.

There’s also I.B.M., serving an industrial site formerly owned by the tech firm, but the ATOC data includes those full stops so it's not quite as short. Compute that, Deep Blue, you chess twat.

10) The longest station name has 33 letters excluding spaces

Okay, I cheated on this and Googled it – the ATOC data only has space for 26 characters. But for completeness’ sake: it’s Rhoose Cardiff International Airport, with 33 letters.

No, I’m not counting that other, more infamous Welsh one, because it’s listed in the database as Llanfairpwll, which is what it is actually called.

 

This sign is a lie. Image: Cyberinsekt.

11) The highest platform number on the National Rail network is 22

Well, the highest platform number at which anything is currently scheduled to stop at, at least.

12) if yoU gAze lOng into an abYss the abySs alSo gazEs into yOu

Image: author's own.

“For I have seen God face to face, and my life is preserved”, said Thomas.

Ed Jefferson works for the internet and tweets as @edjeff.

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