LONDON • The next time your boss tries to convince you of the benefits of working from home, spare a thought for how that could contribute to wrecking the planet.

More businesses than ever are asking employees to work remotely in a bid to cut rental costs for office space and take advantage of the growth of super-fast broadband, teleconferencing and smartphones.

But working from your kitchen can actually increase the carbon dioxide emissions that cause global warming, since those who stay home usually turn up the thermostat. Home energy consumption increases 20 per cent when people work where they live, according to a study by BT Group, Britain's biggest broadband provider.

"The general view is home working is always a good thing, but it's never as simple as it appears," said Mr Paul Swift, a consultant for Carbon Trust, a London-based research group that advises companies on sustainability.

"You can have a very efficient building in a city where people are walking or using public transport. If employees working from home are switching on the heating across the entire house, it will be a negative."

Mr Swift and his team confirmed that working at home during the winter can quickly lead to an increase in emissions.

A single hour of extra heating for most households cancels out the emissions saved by avoiding a commute, the Carbon Trust concluded in a 2014 report.

Only those home workers who live far from the office or who would otherwise drive to work contribute to an overall reduction in pollution.

Employees whose daily car commute is at least 23km, who take a bus for 23km or travel at least 51km by train can cut emissions, the report said.

Those who walk or take public transport would increase their emissions by working from home.

A poll of more than 18,600 people in 26 countries published by research firm Ipsos in 2012 named India, Indonesia and Mexico as the top countries for telecommuting, followed by South Africa, Turkey and Saudi Arabia.

Ten to 35 per cent of the world's workforce worked remotely at least once or twice per week, the report found.

Among environmentalists, there is some suspicion that companies have their own finances in mind when they push employees out of the office.

"Companies are interested in reducing office space for financial reasons," said Carbon Trust's Mr Swift. "The environmental side is not the highest priority."

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