Our main insight was that wearing neckties causes men’s sensory temperature to rise about 2 degrees Celsius. Also, office air conditioning is a primary culprit in greenhouse gas emissions. Putting one and two together, we concluded that the solution lay in changing summer business attire. We called the campaign Cool Biz, and made no-necktie attire the centerpiece. We reasoned that without neckties, men could tolerate the office thermostat being 2 degrees Celsius higher. The previous temperature standard was 26 degrees Celsius, so we proposed raising it to 28 degrees Celsius. We rolled out the campaign through heavy news coverage, events and in-store promotions. Word spread like wildfire.

85.5% of corporations set office thermostats to 28oC (Nippon Keidanren survey), reducing emissions of greenhouse gases by an estimated 460,000 tons — an amount equivalent to that produced by one million households in a month (calculated by the Ministry of the Environment). Awareness of COOL BIZ reached 95.8% two months after launch. Benefits to the economy amounted to approximately 860 million dollars (Dai-ichi Life Research Institute).