April 22, 2013
Today is Earth Day and environmental groups around the world will help raise awareness about environmental concerns.
One of the biggest challenges in recent years is how to combat climate change and greenhouse gas emissions.
The first Earth day on April 22, 1970 is credited with starting the modern environmental movement. It was the brainchild of Democratic Wisconsin Senator Gaylord Nelson. An estimated 20 million Americans participated in the first Earth Day.
Later that same year, the government passed an expanded Clean Air Act and created the Environmental Protection Agency. Now, more than 40 years later, Earth Day is observed by a billion people in 180 nations around the world.