45 years ago, US senator Nelson organised what he called a “national teach-in on the environment”. The Americans were polluting as never before, but didn’t bother about the possible results of their emissions. Instead, protests against the war in Vietnam were the order of the day. Nelson believed he could infuse that energy with an emerging public consciousness about air and water pollution and their country, and believed it would inforce political action. And he succeeded. That 22nd of April 1970, 20 million people took to the streets for a sustainable way of living. In the next years, the EPA (Environmental Protection Agency) was founded, the Clean Air act, Endangered species act and Clean Water act were passed in congress. Earth Day became a yearly tradition and spread all over the world, fostering action to demand environmental protection. It created a social and political platform that is likely to have contributed to the first United Nations Earth Summit in 1992, often seen as the first global conference on climate policy (read more about in my post about the history of climate change policy). Today Earth day celebrates its 45th birthday and the message is clearer and more urgent than ever. Back in the early days, the science of climate change was not yet fully settled. Nowadays, 98% of climate scientists agree present man-made climate change is threatening the Earth in drastic ways. Action is needed, not only the twenty second of April, but every day from now on.