In keeping with tradition, New Yorkers on Thursday will celebrate the 40th anniversary of Earth Day, a day designed to inspire awareness and appreciation for the Earth's environment.

From a walk across the Brooklyn Bridge to raise awareness for clean water projects to an eco-fashion parade in Times Square, New Yorkers will kickstart Earth Day on April 22 with a week filled with climate-related activities.

The Earth Day New York website lists more than 157 separate events in April alone -- many of which will take place on or after April 22nd.

Thousands of people are expected to gather on Friday and Saturday outside Grand Central Station for a two-day festival of art, music and the environment.

Inside the station, a week-long show is illuminating the historic landmark's soaring main concourse with inspiring environmentally themed quotes, messages, photographs and graphic images contributed by artists such as Andy Warhol, Keith Haring, Roy Lichtenstein, and Rafal Olbinski.

New York has a history of going all out to celebrate their appreciation for Mother Earth.

On April 23, 1970, a New York Times article described, "huge, light-hearted throngs" ambling down autoless streets "as the city heeded Earth Day's call for a regeneration of a polluted environment by celebrating an exuberant rite of spring.

For two hours, except for crosstown traffic, the internal- combustion engine was barred from Fifth Avenue between 59th and 14th Streets.

In addition to shutting down Fifth Avenue, then-New York Mayor John Lindsay made Central Park available for Earth Day. The crowd was estimated as more than one million -- by far the largest in the nation.

Earth Day was first realized in 1970 by Wisconsin Senator Gaylord Nelson, who wanted to increase environmental awareness. Now, more than one billion people in 190 countries are expected to attend related events.