A year ago, Mayor Nutter introduced his Greenworks Philadelphia plan, promising to make Philly the greenest city in America with new parks, better air quality and energy-efficient homes.

Sounds daunting, right?

But the impact of the plan is already visible. Over the past year, the city has improved recycling rates and added bike lanes to Center City streets. And Philadelphia received millions from President Obama's $787 billion stimulus plan to set up job-training programs and other green initiatives.

"Especially in hard times, it's something positive that helps people look forward and remain optimistic," said Katherine Gajewski, director of sustainability for the city.

Christine Knapp, director of outreach for the environmental group PennFuture, said the city had made big strides.

"I was at a 'good jobs, green jobs' conference in Washington, D.C., recently. And [Speaker of the House] Nancy Pelosi gave a shout-out to Mayor Nutter," Knapp said. "If they continue on this pace, I don't see why they wouldn't be able to meet these goals."

Greenworks - funded through stimulus and state dollars, as well as existing city funds - set specific targets to reach by 2015. One year in, how much progress has the city made?

Here's a look at some of the key goals:

* Lower city government energy consumption by 30 percent - The moral here is that efficiency should start at home. And city buildings have used 7 percent less energy over the past year, said Gajewski. The city also hired a company to audit its four main buildings to find other ways to cut energy use.

* Improve air quality to meet federal standards - While not yet in full compliance with federal guidelines, air quality has improved, with just 13 unhealthy pollution days in 2009, compared with 20 in 2008.

* Divert 70 percent of solid waste from landfills - In other words, increase the recycling rate. And it is ticking up. Over the past year, the diversion rate was 16 percent of waste, compared with 12 percent during the previous year. Officials expect it to go even higher now that the recycling-rewards program is set to go citywide.

* Provide park and recreation space within 10 minutes of 75 percent of residents - The plan is to add 500 acres of public space. Gajewski said the city is working with neighborhoods to figure out what they want.

* Plant 300,000 trees - This is one of the more ambitious goals. Since Greenworks started, 2,846 trees have been planted. In April, the Department of Parks and Recreation kicked off a tree-planting campaign called "Green Philly, Grow Philly." It is seeking partnerships with private businesses, nonprofits and other organizations to increase the number of trees. But Nutter last week said he would cut $2.5 million the city budgeted to tree-planting, due to financial constraints, which will undoubtedly slow this effort.

* Double the number of green jobs - Last year, the city said it wanted to increase the number of green jobs - loosely defined as jobs with an environmental benefit - from 14,379 to 28,800. So far, it has created at least 520 jobs, largely through stimulus funding for types of construction work.