One million new trees will join the urban landscape of New York City by the year 2017 to reduce air pollution, cool temperatures and help improve the city's long-term sustainability, officials said Saturday.

The tree program is one of 127 environmental proposals that Mayor Michael Bloomberg was set to outline Sunday in a speech at the Museum of Natural History, timed with the observance of Earth Day.

His administration has been working for more than a year on the package of ideas, which is also expected to include a controversial plan to charge motorists extra for driving into certain parts of Manhattan, as a way to cut down on traffic congestion and pollution.

Click here to read about Bloomberg's $8 entry fee plan for Manhattan.

Bloomberg, whose second term expires at the end of 2009, has a goal of reducing New York City's carbon emissions by 30 percent over the next two decades. He has said that the population is likely to grow by another million in that time — up from 8.2 million today — and that the city needs a plan now to deal with the strain on infrastructure and the environment.

The effort was put together by the mayor's Office of Long-term Planning and Sustainability.

On Saturday, city officials announced the tree program, which is to begin this July.

For the next 10 years, the city will plant 23,000 trees each year along city streets, to reach a goal of having a tree in "every single place where it is possible to plant a street tree," Deputy Mayor Dan Doctoroff said.

The remaining will be planted in parks and public lots, while the private sector will also be encouraged to plant trees on their properties as well.

A number of different species will be planted. For each case, foresters assess the sun and shadow levels and other factors to determine the best type for that spot.

Today, New York City has 5.2 million trees, or 24 percent canopy cover. By comparison, Chicago's canopy cover is 11 percent and the rate for Atlanta is 37 percent.

The city said the increase in trees will help cool temperatures, because trees over roads help decrease the near-surface air temperature by 3.5 degrees. They also remove air pollution and reduce ozone, officials said.

The Bloomberg administration will commit another $37.5 million annually to forestry programs, up from $11 million currently, officials said.