A man passes with an umbrella in front of the United Nations Headquarters in New York, March 24, 2008. REUTERS/Mike Segar

UNITED NATIONS (Reuters) - The United Nations is encouraging its New York staff to trade wool business suits for cooler attire this summer so the organization can slash air conditioning costs and help the environment.

“There is going to be a relaxing of the dress protocols and people are being encouraged to wear lighter clothing,” said U.S. architect Michael Adlerstein, who is overseeing a $1.8 billion renovation of the 60-year-old U.N. skyscraper.

Adlerstein said about $100,000 would be saved by turning the thermostats up 5 degrees to 77 Fahrenheit (25 Celsius) in the U.N. secretariat building and to 75 F (24 C) in conference rooms, during a trial run in the scorching month of August.

It would also help the environment in New York City, he said. About 4,400 million pounds of steam -- equivalent to several hundred tons of carbon dioxide -- would be saved by reducing air conditioning at the landmark midtown Manhattan building.

He said staff were being encouraged to shed their trademark dark suits and switch to lighter business casual clothing. Adlerstein sported a white shirt with neither jacket nor tie as he addressed reporters at U.N. headquarters.

“I don’t want to get involved in the fashion police of determining exactly what people can wear, but the encouragement of business casual is where we are going,” he said.

If the trial is a success, thermostats will be turned down 5 degrees in winter. The year-round changes could save up to $1 million annually, Adlerstein said.

Japanese diplomats will likely have an easy time making the transition. In 2005, Japan launched a “Cool Biz” campaign encouraging people to dress down in summer to reduce air conditioning use and greenhouse gas emissions.