Cool Biz: Japan's campaign to reduce air conditioning waste

2025 was the hottest summer on record in Japan , with a national average summer temperature of approximately 2,36°C above average, and everything suggests that 2026 will be even worse. This scenario has further strengthened the Cool Biz campaign , launched in 2005 to reduce energy consumption related to air conditioning in offices during the summer.

The idea is simple: during the warmer months, office staff are encouraged to wear lighter, more informal clothing and to keep the air conditioning around 28°C , thus avoiding having to excessively cool the rooms.

The name Cool Biz is an English contraction of:

• Cool = “fresh”, but also “trendy / casual”
• WE = abbreviation of business

The name was chosen in 2005 by the Japanese Ministry of the Environment through a public competition. The phrase proved particularly effective in its first year because it was short, easy to remember, and evoked a positive image of dressing more casually in the office. In practice, the Japanese government encourages these lifestyles in the workplace:

• no jacket and tie when not essential;
• short sleeve shirts and summer clothing;
• temperature of the tallest buildings;
• lower electricity consumption and consequent lower emissions.

The mechanism of reducing electricity consumption and waste, with the related economic and environmental benefits, works almost automatically:

1. The air conditioning temperature is increased, usually around the 28 ° C, instead of keeping offices much cooler.
2. Lighter clothes are worn, for example short-sleeved shirts and, when possible, no jackets and ties.
3. Feeling more comfortable in summer clothing, people they tolerate higher ambient temperatures better.
4. The air conditioner must therefore cool the environment less and work for less time or with less power.
5. As a result, the decrease electricity consumption, with a reduction in CO₂ emissions associated with energy production.

The Cool Biz campaign also had a cultural effect : it helped make it acceptable, especially in traditionally very formal Japanese professional environments, to dress more casually during the summer.

According to a survey sponsored by the Japanese Ministry of the Environment, 96,1% of respondents are aware of Cool Biz, and 43,2% say their workplace has had its air conditioning turned up higher than before. The government estimates that the campaign saves over 1,15 million tons of CO₂ each year.

The campaign has now become a largely established practice in clothing and air conditioning management , so much so that in 2026 Tokyo further extended it, encouraging polo shirts, T-shirts, sneakers and shorts for public employees as well.

Read also: 

• How to use air conditioning without waste
• Cool home without using air conditioning
• When air conditioning can be harmful