OXFORD, England (Thomson Reuters Foundation) - As climate change brings more frequent and extreme heatwaves around the world, demand for air conditioners is soaring, with 10 new units sold every second on average - but the poor may be left to swelter, said a University of Oxford researcher.

By 2050, energy use for cooling is projected to triple, while in hot countries like India, China, Brazil and Indonesia, it is expected to grow five-fold, the World Bank has said.

“By the end of the century, global energy demand for cooling will be more than it is for heating,” said Radhika Khosla, who leads an Oxford Martin School program on future cooling.

But not everyone will be able to afford to beat the heat.

“Traditionally, energy poverty has been defined as people not having heating. Now that is potentially going to shift, and we could have cooling poverty,” Khosla warned on the sidelines of a conference on efforts to slash planet-warming emissions.

Rising heat is having a huge impact on health – deaths and hospital admissions jump in heatwaves – but also on productivity as workers struggle to cope, climate scientists say.

A 2018 report from Sustainable Energy for All, a U.N.-backed organization, said more than 1.1 billion people globally faced immediate risks from lack of access to cooling.

On a warming planet, cooling is not a luxury but “essential for everyday life”, said the organization’s CEO Rachel Kyte.

But because air conditioners use 20 times as much power as running a fan, their growing popularity could fuel demand for fossil fuel-based electricity that exacerbates climate change.

Rather than relying entirely on air conditioning, buildings should be designed so they are easier to keep cool, which is still rare, said Khosla, who also directs research at the Oxford India Centre for Sustainable Development.

Her modern apartment has windows that open just a few inches, making it hard to keep cool on hot days, she said.

“Net zero” buildings – designed partly to stay cool without heavy use of air conditioning – are popping up around the world, from Southeast Asia to the United States and Europe, but remain the exception, she told the Thomson Reuters Foundation.

Khosla, who has herself lived in a range of hot cities from New Delhi to Chicago, predicted that in the future, housing that cannot be kept cool or have air conditioning installed could see a drop in value, even in relatively cool places such as Britain.

NEW TECHNOLOGY

In some developing nations with rising incomes, buying an air conditioner is also a status symbol, which could make any push for lower-energy alternatives challenging, she said.

Making less power-hungry, affordable air conditioners will be crucial, Khosla believes.

Most machines for sale now – the majority built in China – are half as energy-efficient as they could be, she said.

But researchers are working on more efficient cooling technologies that could hit the market in as little as two years, Khosla said.

Judges are now looking at entries for a $3-million global cooling prize, launched by the Colorado-based Rocky Mountain Institute, aimed at developing an affordable window air conditioning unit that is at least five times more efficient than current models.

Amory Lovins, co-founder of the institute, said designing cheaper, greener air conditioning was “extremely important”.

Getting manufacturers to ramp up production fast - partly by putting in place policies that require greater energy efficiency - will also be key, Khosla said.

Greener cooling is “one of the levers we have left” to hold the line on climate change, and using less energy for cooling would help avert power blackouts in cities on sizzling days, she said.

Cities face an “awful feedback loop” as air conditioners churn out hot exhaust, boosting temperatures further, she said.

All these risks mean smarter cooling must be figured out quickly, before the world gets even hotter and more families rush to appliance shops, she said.

“It’s a future we can’t afford to get wrong,” she warned.