Under the plan, the phase-out of heavy oils from the city's boilers would start right away and be completed by the 2030 deadline. It would reduce the presence of airborne fine particulate matter, which the city says is killing 3,000 residents each year and forcing 6,000 to seek emergency asthma treatment.
The update to PlaNYC, first released by the mayor on Earth Day 2007, was missing one measure that had been a key talking point four years earlier. Bloomberg's congestion pricing plan to charge motorists driving in the busiest parts of Manhattan during peak hours - defeated in 2008 by state legislators - was replaced by other programs.
The ban on the dirtiest heating oils will match or surpass the air quality improvements that had been expected as part of the never-realized traffic fee, said Department of Environmental Protection Commissioner Cas Holloway.
Bloomberg said the traffic problem needs to be confronted.
"The problems of not enough mass transit and too much congestion on our roads and too many pollutants spewed out by combustion engines still persist, and we still have to do something about it," he said.
Overall, the nation's largest city has "achieved or mostly achieved" almost two-thirds of the plan's 2009 milestones - a statistic that city officials say they're pleased about even though budget shortfalls mean that some projects have been delayed.
Since the plan's launch, rezoning efforts have helped make 87 percent of new development accessible by public transportation. An additional 250,000 people - up to 74 percent of the city's more than 8 million residents - live within a 10-minute walk of a park.
And more than 30 percent of the city's 13,000 yellow cabs are now green vehicles.
One of the main goals of the plan - to reduce city greenhouse gas emissions by 30 percent from their 2005 levels - appeared well under way, with the city reporting a drop of 13 percent. But Holloway warned that due to weather and other factors that change each year, it would be inaccurate to say the city had nearly reached the halfway point.
Some advocates said they were disappointed that some pieces of the original plan had fallen by the wayside. Geoffrey Croft, president of the group NYC Park Advocates, said that at least five parks that had been included in the original plan had seen their funding sliced significantly - sometimes by more than 90 percent.
Under the revised plan, the use of the heaviest oil for heating buildings, known as No. 6, will end by 2015. A lighter heating oil, No. 4, would be eliminated by 2030. They would be replaced in part by natural gas and low-sulfur oil, the city said.
The change is aimed at the 1 percent of city buildings that produce 86 percent of the city's building-based soot pollution. The mayor's office said the city would seek to encourage property owners to make the change right away, by working with energy companies to increase the distribution of natural gas and by making it easier for landlords to get permits for boiler conversions.
The city also plans to use $37 million in federal stimulus funds to start a loan program to help property owners pay for energy-efficiency upgrades. The New York City Energy Efficiency Corporation would partner with the commercial lending industry and philanthropic organizations.
Bloomberg said the city also will explore public-private partnerships for renewable energy projects such as building solar power plants on top of larger areas of the city's capped landfills.
If built large enough, the structures to be placed at Staten Island's former Fresh Kills Landfill and two other sites could produce up to 50 megawatts at full capacity, Holloway said. One megawatt is enough electricity to serve 800 to 1,000 homes.
In addition, the revised plan includes new initiatives to open farmer's markets at local community gardens and to give tax abatements to people growing food on city roofs. The city also is increasing its recycling goal and piloting projects to convert waste into energy.
The final measure is especially important in a densely populated city where trash often has been trucked away with a sizable carbon cost, said Steven Cohen, a sustainability management professor at Columbia University, who spoke glowingly of the city's progress on environmental issues over the last four years.
"It's been a landmark for New York City," Cohen said of the plan. "It really demonstrates the mayor's understanding that the environment is not a frill but an essential part of the economic development of the city."
The mayor also released some new details of a previously announced program that will invite residents to join forces online to suggest ways to green the city while also connecting them to environmental projects and organizations. The Change by Us program will ask residents how the city could improve energy efficiency, air quality and community composting efforts.