By Dan Shapley
New York City's mayor Michael Bloomberg unveiled a plan to plant 1 million new trees, as part of the city's plan to combat climate change and prepare for population growth. The city will plant trees in parks and along streets, and developers will be required to incorporate plantings into their projects. The city estimates that for every dollar spent, it gains $5 in "services" from the urban forest. Trees improve air quality, shade hot city streets and absorb carbon dioxide. All that, and they increase property values too.