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The CO2 Calculator
The CO2 calculator can be used to calculate CO2 emissions from everyday Japanese electrical appliances and automobiles based on energy consumption figures. By marking the appliances you use and filling out the required information, you can get a quick idea of how you can impact on the environment through your lifestyle. The final calculation is based on the number of households in Japan, and points out how people impact on the environment as a collective force. Try adding and subtracting the various items to see what products tend to have larger impacts.

While the figures and calculations are based on a Japanese context, it does help in illustrating the kinds of impact that everyday appliances can have on the environment. Indeed, not all electrical appliances used in a typical Japanese household are included, but demonstrates causal relationships!!

Colour TV (Standard) hrs/day:
Colour TV (Wide screen) hrs/day:
Air-conditioner (heater) No.of rooms : hrs/day:
Air-conditioner (cooler) No. of rooms: hrs/day:
CD-Player hrs/day:
Microwave Oven No. of times/day:
Vacuum Cleaner No. of times/day:
Video player
Automobile (manual)
Average daily kms driven:
Car's average kms/ltr:
Automobile (automatic)
Average daily kms driven:
Car's average kms/ltr:

Your daily CO2 emmissions: kgC/day
Your yearly CO2 emmissions: kgC/yr
Japan yearly CO2 if everyone had lifestyles like you: kgC/yr

Source: The CHOCO2 Study carried out by the Global Environment Information Center, Tokyo, Japan

  • Automobiles
    The full list covering 1642 vehicles, divided Japanese automobiles into categories such as "deadweight of vehicle" "type of vehicle", and ranked them by their estimated CO2 emissions. This was calculated according to a formula depending on the type of fuels (gasoline or light oil). CO2 emission from burning one liter of gasoline is calculated to be 0.64kgC/L, according to figures from the Environment Agency of Japan.

  • Refrigerators
    An extensive number of sizes and categories of refrigerators were examined, from 0-449L with varying results. Results showed that multifunctional refrigerators emitted most CO2, particularly those with little depth.

  • Air conditioners:
    With air conditioners, a variety of factors were accounted for, including heater- and cooler-based air conditioners, and the power of the motors. Japanese manufacturers measure the equipments' power according to the number of tatami mats it can cool or heat. For the purposes of the study, one room is equal to a six tatami mat room; 1.5 rooms to 8 tatami mats; and 2 rooms to 10 tatami mats. For heaters, calculations were based on use of 5 hours/day over 4 months/year; and for coolers, 5 hours/day over 3 months/year.

  • Televisions
    There are a large variety of television sets available on the market. The "wide" televisions with their broader screens were shown to emit up to 3-4 times the CO2 of the "standard" or conventional TVs. In line with the recommendations in the Energy Conservation Law in Japan, calculations were based on an average 4.5 viewing hours per day.

  • Video decks
    Results of video decks reminded us that people often leave their video decks on all the time. While emissions varied among the models, it was found that the ratio of CO2 emissions between idle video decks and those in use, were similar depending on the model.

  • CD players
    Some 72 types of appliances were examined under this category. It was found that differences between electricity consumption among the models were large, from an equivalent of a 2 light bulb consumption to 5 fluorescent lights (30W).

  • Word processors
    In word processors, CO2 emissions and electricity consumption depend very much upon the model, with a differing factor of two among the models. The ratio of electricity consumption and respective CO2 emissions among the models was roughly equal. In other words, the more electricity an appliance consumes, the higher the emissions will be.

  • Faxes
    As for faxes, there were variations of up to 300% in CO2 emissions and energy consumption among the models surveyed. Those faxes using normal paper feeds were shown to require more electricity.

  • Laptops
    Variations in CO2 emissions and energy consumption among the models ranged up to 200%.

  • Colour printers
    There are a variety of colour printers available on the market, both big and small. There was a four fold difference among the models in CO2 emissions when in use, and two fold when idle.

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