The development of ever taller skyscrapers coincides with the constant innovation and development of the passenger lift. In fact, were it not for Elisha Otis’ innovative safety elevator, the gigantic buildings that threaten to pierce the skies above major cities would not be possible.

Currently the tallest complete and functional lift is in the world’s tallest building, the Burj Khalifa in Dubai has the record for the tallest lift in the world, spanning 504m of the 828m building.

It has held this record since the building’s completion in 2009, although should Jeddah Tower be completed it is set to have a 660m tall lift.

Part of the problem with building a lift that size is the need to scale up the cables and other mechanisms.

At one point it was believed that travelling more than 500m was impossible because the steel cabling became so thick it needed cables to support the cables.

This problem was sorted by the creation of a friction-proof carbon-fibre material that was seven times lighter and theoretically makes a 1km lift possible.

As well as racing to build the tallest lifts, these super skyscrapers also need lifts that are incredibly fast without being uncomfortable. There is currently an upper limit to this caused by the human body.

Skyscrapers are so tall that there is a change of air pressure before you reach the top, as air gets thinner. This causes big problems when descending as passengers can feel that rapid compression, usually in the form of ear discomfort.

This is the same reason why you can feel your ears pop during a flight, and this will be a limiting factor that requires clever traffic management and air-pressure adjustment to minimise the effects.