On April 22, 1970, the US went climate crazy as 20 million Americans took part in the very first Earth Day. Gaylord Nelson, a democratic politician from Wisconsin had proposed the idea of holding a nationwide environmental "teach-in" at colleges to raise awareness of human impact on the environment. 3 years later, the first environmental protection legislation had been passed and the Environmental Protection Agency was created. Today more than a billion people take part in Earth Day events across the globe.