Better insulation at home, less use of the car and even giving up an electric toothbrush can help people in rich nations halve emissions of greenhouse gases, a UN report said yesterday.

"Adopting a climate-friendly lifestyle needn't require drastic changes or major sacrifices," according to the 202-page UN Environment Programme (UNEP) book entitled Kick the CO₂ Habit: the UN Guide to Climate Neutrality.

Issued to mark the UN's annual World Environment Day, celebrated yesterday, it outlines ways for people to combat global warming with measures such as packing lighter suitcases when flying or going jogging in a park rather than on an electric treadmill.

World emissions of greenhouse gases blamed by the UN Climate Panel for heating the globe total about 4.5 tonnes per person for all of the world's 6.7 billion population.

Most efforts to slow climate change focus on the role of governments - such as in rules for emissions from cars or power plants or building codes to help avert projected impacts such as droughts, heat waves, more powerful storms or rising seas.

Fewer look at how individuals can do it themselves.

"Multiplied across the world and acted upon by 6.7 billion people, the public have the power to change the future, have the power to personally and collectively influence economies to Kick the CO₂ Habit," said Achim Steiner, head of UNEP.

The guide outlines ways for people in Europe, Australasia and North America - the major contributors to global warming historically - to halve their emissions. Among examples and their savings of carbon dioxide (CO₂):

• Use a wind-up alarm clock rather than an electric one: 48 grams CO₂ a day.

• Dry clothes on a washing line rather than in a tumble dryer: 2.3 kg each load.

• Pack lighter suitcases. It says that world savings would be two million tonnes a year if every airline passenger cut the weight of baggage to below 20 kg and bought duty free goods on arrival.

• Use a non-electric toothbrush: 48 grams a day.

• Heat bread rolls in a toaster rather than in the oven for 15 minutes: 170 grams of CO₂ each time.

• Take a train rather than a car for a daily commute of eight kilometres: 1.7 kg CO₂ a day.

• The average British household could cut two tonnes of CO₂ annually with more efficient insulation, heating and lighting.

• Reduce winter heating: Cutting the temperature by a couple of degrees saves six per cent in energy bills.

• Avoid 'carbon binges': A return flight across the Atlantic is equivalent to running a car for a year for each passenger.