People who work remotely all the time produce less than half the greenhouse gas emissions of office workers, according to a new study.

Employees in the US who worked from home all the time were predicted to reduce their emissions by 54%, compared with workers in an office, the study found. But hybrid workers did not reduce their emissions so dramatically, according to the research published in the Proceedings of the National Academy of Sciences.

One day of remote work a week reduced emissions by just 2% because energy savings from not being in the office were offset by factors such as an increase in non-commuting travel when working from home. Working remotely two or four days a week reduced an individual’s emissions by up to 29% compared with on-site workers.

Researchers from Cornell University and Microsoft used multiple datasets including Microsoft’s own employee data on commuting and teleworking behaviours to model the predicted greenhouse gas emissions of office workers, remote workers and hybrid workers in the US, examining five categories of emissions including office and residential energy use.

They found that IT and communications technology had a negligible impact on individuals’ work carbon footprints.

The main causes of remote workers’ reduced emissions were less office energy use, as well as fewer emissions from a daily commute.

Wider emissions reducing benefits of working from home include the easing of vehicle congestion during rush hour in commuting areas, which is likely to improve fuel economy. But the authors warned that working from home needed to be carefully planned to deliver emissions saving benefits.

“People say: ‘I work from home, I’m net zero.’ That’s not true,” said the co-author Fengqi You of Cornell University. “The net benefit for working remotely is positive but a key question is how positive. When people work remotely, they tend to spend more emissions on social activities.”

The study found that remote workers’ non-work travel increased, with more driving and more flying. You said that homes were not always optimised for decarbonisation, in terms of using renewable energy and the efficiency of appliances, and there were some scale-related energy savings. For instance, a small home printer is likely to be less energy efficient than an office printer.

The Covid-19 pandemic created a remote working revolution for many office workers. In the US and elsewhere, many people relocated from “high-density commuting zones” – relatively close to major cities and offices – to more rural “low-density commuting zones”. According to the study, this could result in longer commuting distances for hybrid workers and a greater carbon footprint due to the increased use of private vehicles.

The authors said: “While remote work shows potential in reducing carbon footprint, careful consideration of commuting patterns, building energy consumption, vehicle ownership, and non-commute-related travel is essential to fully realise its environmental benefits.”

While the findings do not apply to workers in many sectors – a bus driver, for example, cannot work from home – it provides pointers on how office-based employers can reduce company emissions.

You said that while the findings were specific to the US, the modelling and trends were likely to be replicated in Europe and Japan. He called on companies to look at energy efficiency measures, downsizing and sharing office space. “By sharing office space we reduce capacity and size and reduce our office energy consumption,” he said.

The study found that IT and communications accounted for a small percentage of overall emissions and therefore emissions reduction should focus on renewables for office heating and cooling, as well as decarbonising commuting.