Short of roof gardens, what's another way to cool down sweltering urban environments and manage runoff? Good old-fashioned trees.

Gothamist tells us of Mayor Bloomberg's plan to plant a million trees in New York City's five boroughs in the next ten years as part of PLANYC 2030, a set of over 100 initiatives for a "greener, greater New York." The announcement, made on Earth Day, calls for the trees to line streets, adorn parks and add an arboreal touch to vacant lots. To get the ball rolling, the city will triple the yearly tree planting budget to $37.5 million.

What about alternative energy? The city has a plan for that too.

• Create a property tax abatement for solar panel installations
• Study the cost-effectiveness of solar electricity when evaluated on a Real Time Pricing scenario
• Support the construction of the city's first carbon neutral building, primarily powered by solar electricity
• Increase use of solar energy in City buildings through creative financing
• Work with the State to eliminate barriers to increasing the use of solar energy in the city
• Pilot one or more technologies for producing energy from solid waste
• End methane emissions from sewage treatment plants and expand the productive use of digester gas
• Study the expansion of gas capture and energy production from existing landfills

If it all goes according to plan, NYC's soot-encrusted reputation may be a thing of the past...