At Northwestern University in north suburban Evanston, the campus of 18,000 people turned out their fair share of garbage - 10 tons of trash. Students and activists built a mountain of garbage to bring awareness to the waste.
"Earth Day gives us a target and specific date to shoot for when they are aware of the issues and they like to see something happen for Earth Day and this is a fun outdoor event where we get people walking by," said Julie Cahillane, NU recycling coordinator.
RC Yu, head of Engineers for a Sustainable World at Northwestern, said he hated the environment degradation he grew up with in his native malaysia, especially the foul air from Indonesia.
"People living above Indonesia, to the north of Indonesia, get the smoke from the forest clearing. Sometimes it's so terrible kids have to wear masks to go to school or there's an emergency where you can't go out," said Yu.
Building environmental awareness is the goal at the Bronzeville Children's Museum. Children chanted "reuse, reduce, and recycle" Thursday.
"At last people are beginning to take notice to the fact that Earth Day is importance for us to observe and to live because the earth and the resources," said Peggy Montes, Bronzeville Children's Museum.
"The challenges-- Asian carp, global warming, the economy we're in-- but a really important lesson is when we put our minds to it, we can make real progress on these problems," said Jack Darin, Sierra Club.
Students at the University of Illinois at Chicago celebrated with an "Ecojamapalooza." The event featured many educational displays and demonstrations. It also highlighted sustainability initiatives at the university.
UIC has taken many steps to improve energy efficiency. They include an expanded recycling program and the use of geothermal wells and solar panels.
"It is our generation that has a responsibility to make a difference in environmental consciousness through our actions towards protecting and preserving the earth," said Jose Valencia, Green Youth Movement.
Governor Pat Quinn joined the celebrations and encouraged students to pursue environmental courses and careers to make Illinois a better place to live.
And volunteers were out in Jackson Park for a day of tree planting and springtime sprucing up this Earth Day. The group Friends of the Parks and volunteers from the Exelon Corporation planted 25 new trees and provided grooming and fresh mulch to dozens more. They say once the 25 new trees mature, they will be able to absorb 1,200 pounds of carbon dioxide per year.
According to the National Oceanic and Atmospheric Agency, or NOAA, since 1970 global carbon dioxide emissions have doubled, the polar ice cap has shrunk, and the EPA says waste generated by Americans has increased by about a third -- with a third of that now being recycled. Environmentalists say, however, 40 years of Earth Day shows what can be accomplished.