Green is the color of choice lately for Mayor Gavin Newsom, who unveiled Wednesday yet another effort to make The City environmentally friendly.

Newsom proposed a new green building ordinance that would apply to new commercial and residential development as well as renovations to existing buildings.

The green building proposal would impose stringent environmental standards on new construction and renovation to current buildings, according to Newsom. The standards would increase every year through 2012, when The City hopes to have reduced greenhouse gas emissions by 20 percent of 1990 levels, according to a press release from his office.

In 1990, The City as a whole released 4.5 million tons of carbon dioxide into the air, and today that figure stands at 9.3 million, according to the Mayor’s Office.

“You’d start with a high bar relative to any city in the country, and that bar would simply increase each and every year,” Newsom said.

If the Board of Supervisors passes the ordinance in January — as the mayor said he expects — new commercial buildings of more than 5,000 square feet, residential buildings more than 75 feet tall, and renovations on buildings more than 25,000 square feet must be certified by standards of Leadership in Energy and Environmental Design, or LEED.

LEED standards go up to platinum — The City’s new Academy of Sciences building in Golden Gate Park is LEED Platinum with its living roof — and by 2012, most large buildings in The City must meet LEED Gold or Silver standards, according to the proposed ordinance.

New commercial buildings smaller than 25,000 square feet and shorter than 75 feet, as well as small residential buildings will also have standards placed upon them.

But the standards — and high cost of materials and technology to reach them — would be offset by the energy efficiency and improved quality of life for a building’s tenants, said Phil Williams, the chairman of a city task force on green building and vice president of Webcor Builders.

The announcement comes on the tails of proposals for a carbon tax to spur energy conservation, a city-sponsored solar incentive program and a grease recycling initiative.

As for future green initiatives, Newsom said he plans to announce approximately six more that will move The City into the forefront of environmentally friendly cities.

“We’re going to be making a lot more announcements about reorganization around this priority in the new term as well,” he added.

Green effects

Environmental benefits officials expect San Francisco’s new green building ordinance to achieve through 2012:

» Reducing carbon-dioxide emissions by 60,000 tons

» Reducing waste and storm water by 90 million gallons

» Reducing construction and demolition waste by 700 million pounds

» Reducing auto trips by 540,000

» Saving 220,000 megawatt hours of power

» Saving 100 million gallons of drinking water

» Increasing green power generation by 37,000 megawatt hours

» Increasing the value of recycled materials by $200 million