More than one million students in New York City are skipping school to protest the climate crisis. The New York City Department of Education will not penalize students for taking part in the protests. In response to the decision, Jamie Henn -- the founder of climate organization 350.org -- Tweeted, "this is so cool! NYC Public Schools are letting students leave class to join the on September 20th."\u00a0He added,\u00a0"also, holy smokes, this thing could get HUGE." Activists hope that the climate strikes will the biggest ever, with 800 protests planned across 50 states. Potentially, millions more will turn out across the world. In the UK, the Trades Union Congress and Amnesty International are backing the strikes. Kumi Naidoo -- the secretary-general of Amnesty International -- hopes that schools will allow all students to protest without punishment. He has written to nearly 25,000 schools in the UK -- as well as 2,000 in Hungary, Spain, New Zealand, and Canada -- asking headteachers not to penalize students who leave class to protest for climate action. A Human Rights Issue In his letter, Naidoo wrote, "I believe that for the cause for which these children are fighting is of such historic significance that I am writing to you today with a request to neither prevent nor punish your pupils from taking part in the global days of strikes planned for 20 and 27 September." "The climate emergency is the defining human rights issue for this generation of children,"\u00a0he continued.\u00a0"Its consequences will shape their lives in almost every way imaginable. The failure of most governments to act in the face of overwhelming scientific evidence is arguably the biggest inter-generational human rights violation in history." The strikes are inspired by Swedish teen Greta Thunberg. The vegan environmentalist started off by skipping school on Fridays to protest for climate action in Sweden. She is now famous around the world for her climate activism. She recently arrived in the U.S. on an eco-friendly superyacht and since then she has met with former President Barack Obama. During the meeting, the pair fist-bumped and Obama told her, "you and me, we're a team."