As the temperature rises, sweaty and flustered humans are kickstarting a feedback loop that is further exacerbating the problem of climate change. At present, the world has 1.6 billion air conditioning units, which collectively use a staggering ten per cent of all global electricity demand. While less than a third of households globally are so equipped, the most AC-addicted countries are Japan (in 91 per cent of households), the US (90 per cent) and South Korea (86 per cent).

New research by the International Energy Agency (IEA) estimates that the total number of units is set to more than triple to 5.6 billion by 2050 – equal to ten new units being sold every second for more than 30 years – with sales driven particularly by India, China and Indonesia. This will make the use of air conditioning one of the world’s largest demands for energy, equivalent to adding the entirety of the EU, the US and Japan’s current energy capacity to the global grid.

‘Growing electricity demand for air conditioning is one of the most critical blind spots in today’s energy debate,’ argues Fatih Birol, executive director of the IEA. ‘With rising incomes, air conditioner ownership will skyrocket, especially in the emerging world. While this will bring improve daily lives, it is essential that efficiency performance be prioritised.’

Birol and the IEA emphasise the need for new efficiency standards to ensure that consumers are at least buying units that require significantly less power to function, therefore mitigating the overall energy demand. Variations on the traditional ‘vapour compression’ technology which has formed the basis for AC units for more than a century, may figure prominently. A water-based system was recently developed by researchers at the National University of Singapore (NUS) which, by using a de-humidifying membrane instead of chemical refrigerants such as chlorofluorocarbon and hydrochlorofluorocarbon, uses 40 per cent less electricity, and produces only one by-product: potable drinking water.

‘Our cooling technology can be tailored for all types of weather conditions, from humid climate in the tropics to arid climate in the deserts,’ says associate professor Ernest Chua from the Department of Mechanical Engineering at NUS. ‘While it can be used for indoor living and commercial spaces, it can also be easily scaled up to provide air-conditioning for clusters of buildings in an energy-efficient manner.’

This was published in the July 2018 edition of Geographical magazine

Get the best of Geographical delivered straight to your inbox by signing up to our weekly newsletter and get a free collection of eBooks!