Go green, hang your washing out (Image: silkegb/Getty)

If only Americans would hang their laundry out to dry – and commit 16 other acts of environmental kindness – they could slash US carbon dioxide emissions by 7.4 per cent by 2019.

Thomas Dietz of Michigan State University in East Lansing and his team calculated the carbon-saving impact of 17 practices, such as eschewing tumble dryers, car pooling and buying fuel-efficient vehicles (see the full list below).

By drawing on previous studies, Dietz estimated what proportion of the population could realistically be persuaded to change their behaviour using financial incentives, mass-media campaigns and so forth. For example, 90 per cent of Americans are likely to take up better home insulation, though only 15 per cent would go in for car pooling.


The team found that by 2019, US households could cut their annual emissions by 20 per cent – representing slightly more CO 2 than France spews out each year.

Canada and Australia should pay attention, too: Dietz reasons that these two countries, “which have carbon profiles roughly comparable to that of the US”, may be able to achieve similar savings.

Everyday shift

“This study is the best estimate we have to date of how effectively behavioural change could cut US greenhouse gas emissions,” says Ruth Rettie, who leads Project Charm, a group based at Kingston University in London that investigates ways in which people’s behaviour could be influenced.

“Everyday household practices – for example tumble drying or using air conditioning – are resistant to change because they are embedded in conceptions of comfort and convenience,” says Rettie. “But with the right combination of policy tools and social marketing, interventions can result in major behaviour changes.”

Journal reference: Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.0908738106

17 things you can do to reduce your carbon footprint Weather-proof your house: seal drafts, insulate lofts, triple-glaze windows Centralise your air-conditioning system Install low-flow showerheads Get a more efficient water heater Use energy-efficient appliances Fit low rolling-resistance tyres to cars: they minimise the energy wasted as heat as the tyre rolls down the road Use a fuel-efficient vehicle Change the air filters on your centralised air conditioning Tune up your air conditioning: get annual professional inspection and maintain it well Get regular car maintenance checks Wash your clothes at a cooler temperature Turn the temperature on your water heater down Stop leaving unused appliances on standby settings, which use power Turn your thermostat down Avoid the tumble dryer: line-dry washing Drive at a maximum of 90 kilometres per hour (55 miles per hour) Car pool and “trip-chain”, running errands together