BBC: The climate benefits of a four-day workweek
“"Although climate benefits are the most challenging thing to measure, we have a lot of research showing that over time, as countries reduce hours of work, their carbon emissions fall," she says. A 10% reduction in hours is associated to an 8.6% fall in carbon footprint, according to a study co-authored by Schor in 2012.”
“Data from the US Energy Information Administration also shows people in the US burn nearly 10% less fossil fuels on weekends than they do on weekdays. So he believes shifting Friday from a weekday to a weekend day could represent a significant improvement in fossil fuel emissions. "These numbers show that the four-day week can really have a substantial impact," John Leland says.