Secretary-General Ban Ki-moon is inviting world leaders to the United Nations on April 22,"Earth Day," to sign the landmark agreement to tackle climate change that was reached in Paris, AP reported. Ban told reporters Monday he wants leaders of the nearly 200 countries that approved the deal on Saturday to come to U.N. headquarters on the first day it opens for signing "because this will be the first-ever universal climate change agreement." He said the United Nations is also organizing an "action summit" on May 5-6 for government, business and civil society to focus on implementation of the agreement. "The Paris Agreement sends a clear signal that the transformation of the global economy to low-emission, climate-resilient growth is inevitable, beneficial and already under way," Ban said.