The UK public are being invited to participate in a mass experiment to reduce climate change as part of National Science Week.
10 Downing Street is also getting energy-saving bulbs fitted
"Click for the Climate" invites people to pledge to make a small change to their lifestyle during science week to reduce carbon dioxide emissions.
Chief scientist, Sir David King, said cutting emissions is up to individuals, as well as government and industry.
The Prime Minister has added support by lowering his thermostat by one degree.
The British Association for the Advancement of Science (BA), which co-ordinates National Science Week, is asking people to visit its website to make an online pledge for a "green" lifestyle change, revealing the estimated carbon dioxide savings if the action is kept up for a week.
The pledges include:
Supermarkets were also invited to take part in the campaign, and Sainsbury's, Morrisons and Waitrose are reducing the prices of energy-saving light bulbs for the duration of the week.
- not to going to school or work by car, saving 4.5kg of CO2
- unplugging phone chargers when not in use, saving 1kg of CO2
- fitting three low energy light bulbs, saving 1.4kg of CO2
- off-setting one return air flight by planting a tree, saving 1,000kg of CO2
- not leaving electrical equipment on stand-by, saving 0.6kg of CO2
Professor Sir David King, the government's chief scientific adviser, launched the campaign and said reducing greenhouse gas emissions is the greatest global challenge we face today.
"We in government have a particular responsibility, and hence our emphasis on reducing our emissions by 60% by 2050.
"At the same time it is a problem for each individual to think about, and this is why the 'Click' campaign is brilliant, because it brings home to each individual their own responsibilities," he said.
The Carbon Reduction Programme (CRed), at the University of East Anglia, will evaluate the results of the campaign, and encourage people to continue their "greener" lifestyles.
More than 500,000 people are expected to take part in National Science Week.
"If they all just replaced one ordinary light bulb in their home with an energy saving bulb, then National Science Week would have cut down carbon dioxide emissions by over 240 tonnes," explained Roland Jackson, chief executive of the BA.
"People say they can't make a difference - this shows that they clearly can!"
Famous faces who have also joined the campaign include athlete Colin Jackson, who is swapping domestic flights for the train, and scientist Robert Winston, who is giving up the use of his car.
National Science Week, which this year also incorporates Social Science Week, takes part from 10-19 March. More than 1,500 events will be happening throughout the UK.