According to a household waste study by the Open University for DEFRA, the average household produces 18.6 kg of waste per week. The vast majority of this waste can be recycled. For an average household this equates to 38.2 kg CO2 per household per week. 

Source: Do the Green Thing

A running tap flows at 6 litres per minute – which is about 24 litres of water a day. If you use a glass of water to rinse your mouth that’s approximately 1 litre per day, saving 23 litres of water a day.

Source: We Are What We Do

If you forego a bath in favour of a shower just once a week, you can save 45 kg of CO2. If you do this daily, it adds up to 315 kg of CO2 a week. 

Source: Reduce your CO2 

In a typical home, one compact fluorescent bulb can save 260 pounds / 120kg of CO2 per year.                                [Source: Ecomail] This equates to 2.3kg per week or 4.6kg for changing 2 light bulbs. 

If every household installed just one energy saving light bulb, the electricity saved in a year could power the Blackpool Illuminations for nearly 900 years and there would be enough carbon dioxide saved to fill the Royal Albert Hall 1,980 times! [Source: Energy Saving Trust]

Every person in the country uses an average of 167 plastic bags every year or 3-4 a week. 

The volume of the average plastic bag is 50 cm3

Source: We Are What We Do

On average the carbon emissions per person for a one km journey is 89g by bus, and 133g by car, making a saving of 44g/km if you take the bus instead of driving or 133g/km if you walk. We’ve decided that a short journey is 2km and that on average people make 12 of these journeys a week. And we're asking people who make this promise to walk! 

12 journeys x 2km x 133g saved/km= 3.192 kg (rounded to 3.2kg) saved a week for everyone promising this action

If you only eat meat once a week you save 48kg CO2. 

Source: Part-time Carnivore

Food typically travels 2,500 km before it gets to you. Each of those miles involves the emission of CO2. To avoid this contribution, support your area's agriculture: visit a farmer's market, look for regional produce at the grocery shop or create a garden of your own. If you eat local food just once a week, you can save 2,268 kg CO2 over the course of a year, or 43.62kg a week. We're asking you to do this 3 times a week so this equates to saving 131 kg of CO2 a week

Source: Reduce Your CO2