See an aerial view of the Climate Strike march in lower Manhattan. More: Thousands of people took to New York City streets Friday to help fight climate change, joining worldwide demonstrations ahead of a U.N. summit. Public schools throughout the city even let kids skip class to join the cause. With home-made signs, some which read "The Earth. Is. Not. Expendable (Period)," "¡PUERTO RICO SE LEVANTA!" and "WE ARE MISSING OUR LESSONS SO WE CAN YEACH YOU ONE," the enthusiastic crowd flooded the Big Apple in hopes of having their message heard. The sea of young people, including Swedish activist Greta Thurnberg and two of the 21 young plaintiffs who filed a constitutional climate lawsuit against the U.S. government, among other climate activists, took over the streets, assembling at Foley Square to march to Battery Park for a rally. The flood of people marching in New York City, holding signs as they chanted, mirrored similar rallies across the globe. Activists are calling for immediate action from the world's governments to halt global warming, reduce fossil fuel consumption and avert environmental catastrophe. Thunberg says that rather than listen to her and other young activists, lawmakers should invite scientists to the Capitol to listen to their expertise on ways to slow a rise in global temperatures, Thunberg said. "This is not about us. This is not about youth activism," she said. "We don't want to be heard. We want the science to be heard." NBC 4 New York on Twitter: 4.nbcny.com/kAuuwUN NBC 4 New York on Facebook: 4.nbcny.com/mbeh714 NBC 4 New York on Instagram: 4.nbcny.com/g5YlkcI NBC 4 New York on Youtube: 4.nbcny.com/iTUpy5e #News #ClimateStrike #NYC #News ----------------------------------------------- NBC 4 New York / WNBC is the flagship station of the NBC Owned Television Stations division of NBCUniversal, serving the New York Tri-State area with an unparalleled commitment to broadcast excellence for more than 75 years. For more information about NBC 4 New York, visit NBCNewYork.com.